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1
Lowe, Brian D. "Modelling the additivity of perceived exertion in symmetric, mid-sagittal lifting". Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06112009-063305/.
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2
Li, Jian-Chuan. "Three dimensional kinetic analysis of asymmetrical lifting". Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1018240.
Testo completoAbstract (sommario):
Manual lifting is dynamic in nature and involves asymmetrical loading of the human body. This study investigated kinematic and kinetic characteristics of asymmetrical lifting in three dimensions, and then constructed a 3-D biomechanical force model of the lower back which is capable of quantifying torsional stress on the human spine. Eleven healthy adult male manual workers were recruited as subjects and lifted a 1 Okg load placed at the sagittal plane (0°) and at 30°, 60° and 90° lateral planes to the right, from 150mm and 500mm initial lift heights, respectively, to an 800mm high bench in the sagittal plane. Subjects' spinal motions and the trajectorial movements of the load in three-dimensional space were monitored simultaneously by a Lumbar Motion Monitor and a V-scope Motion Analyzer. Generally, the spinal motion factors increased as a function of increasing task asymmetry and differed (p < 0.05) between the lower (150mm) and higher (500mm) levels in the sagittal plane. In all asymmetrical conditions the motion factors showed a dramatic increase at the 500mm level compared to the increase at the 150mm level. The rates of increase in the horizontal and frontal planes were greater than those in the sagittal plane. Task asymmetry had a significant effect on the spinal kinematic parameters in the frontal plane at the two lift heights, and only at the high level (500mm) in the horizontal plane, with exception of average acceleration . Initial lift height exerted a significant effect on peak velocity and acceleration in both frontal and horizontal planes and on range of motion in the horizontal plane. Kinetic characteristics of the object being lifted in three-dimensions increased with an increase in task asymmetry. The increase was more dramatic in the lateral direction in the horizontal plane. However, motion factors in the vertical direction dominated the full range of the lift, irrespective of task asymmetry and lift height. The kinetic measures differed (p < 0.05) between the lower ( 1 50mm) and the higher (500mm) levels in the vertical direction except for average force. Task asymmetry had a significant effect on dynamic measures in the anterior-posterior direction. Both task asymmetry and lift height had a significant effect on dynamic motion factors in the lateral direction. From insights gained in the empirical study a three-dimensional biomechanical force model of the lower back was constructed based on a mechanism of muscle force re-orientation in the lumbar region. Acknowledging that the lower back is designed to be able to rotate around its longitudinal axis, the proposed model accounts for compression and shear forces and a torsional moment. The model has similar predictability to Schultz and Andersson's (1981) model when the human trunk exerts only a flexion-extension moment in the sagittal plane, but additionally predicts dramatic increases in shear forces, oblique muscle forces and torsional moment under asymmetrical lifting conditions which the Schultz-Andersson model does not. The increase rates in these forces and moment are not linearly related over task asymmetric angle.
3
Hartsell, Jared J. "The development of a dynamic scissor lift model". Morgantown, W. Va. : [West Virginia University Libraries], 2010. http://hdl.handle.net/10450/11215.
Testo completoAbstract (sommario):
Thesis (M.S.)--West Virginia University, 2010.Title from document title page. Document formatted into pages; contains vii, 55 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 53-54).
4
Ng, Kim-ching, e 吳劍青. "Prevention of occupational injuries caused by manual handling in health care settings: costs and benefits". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42997574.
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5
Salazar, Nicolas F. "Determination of the range of safe-comfortable lifting postures using the aesthetic ergonomics theory". Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10020.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--West Virginia University, 2009.Title from document title page. Document formatted into pages; contains xii, 196 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 141-146).
6
Ng, Kim-ching. "Prevention of occupational injuries caused by manual handling in health care settings costs and benefits /". Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42997574.
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7
Noone, Gregory P. "Biomechanical modelling of some musculo-skeletal problems /". Title page, table of contents and summary only, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phn817.pdf.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--University of Adelaide, Dept. of Applied Mathematics, 1994.Copies of author's previously published articles inserted at back. Includes bibliographical references (leaves 211-220).
8
Baggio, Viviana Carolina. "Comparison between human perception of risk of injury and NIOSH WPG for lifting tasks". Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4636.
Testo completoAbstract (sommario):
Thesis (M.S.)--West Virginia University, 2006.Title from document title page. Document formatted into pages; contains x, 107 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 68-71).
9
Munn, Kemal. "Analysis of XYZ company's powder transfer in the processing department". Menomonie, WI : University of Wisconsin--Stout, 2006. http://www.uwstout.edu/lib/thesis/2006/2006munnk.pdf.
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10
Choi, Chun-yeung. "A generic fatigue model for frequently performed, highly repetitive combined material handling". Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B37841464.
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11
McKay, Renée Denise. "Observing mothers lifting their children in their own home to identify factors which might give rise to musculoskeletal disorders a thesis submitted to Auckland University of Technology in partial fulfilment of the requirements for the degree of Master of Health Science (MHSc), 2008". Click here to access this resource online, 2008. http://hdl.handle.net/10292/400.
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Heintz, Jeffrey R. "The effect of a 6-week program of isolated back extension strength training on lifting capacity : comparison of an isokinetic vs. isotonic training regimen /". Click for abstract, 1998. http://library.ctstateu.edu/ccsu%5Ftheses/1492.html.
Testo completoAbstract (sommario):
Thesis (M.S.)--Central Connecticut State University, 1997.Thesis advisor: Dr. Robert Trichka. " ... in partial fulfillment of the requirements for the degree of Master of Science in Physical Education." Includes bibliographical references (leaves 162-169).
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Culligan, James T. "A risk assesement of nursing personnel injuries occurring while lifting, transferring or repositioning nursing home residents". Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1507.
Testo completoAbstract (sommario):
Thesis (M.S.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains x, 92 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 81-82).
14
Holman, Grady Talley Thomas Robert Evans. "Patient handling restrictions & conditions". Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Fall%20Dissertations/Holman_Grady_7.pdf.
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15
Lehmann, Frederick Denis, University of Western Sydney, of Science Technology and Environment College e School of Environment and Agriculture. "Weight load carry : a review of the efficiency and effectiveness of the army backpack". THESIS_CSTE_EAG_Lehmann_F.xml, 2000. http://handle.uws.edu.au:8081/1959.7/663.
Testo completoAbstract (sommario):
Military load carrying has occupied the attention of military developers, researchers and commanders over centuries. The Army backpack remains the means of carriage for ammunition and rations for the soldier in the field. The traditional rationale for its use has been that the infantry soldier must be able to sustain himself in combat and live independently for days at a time without resupply. At the Royal Military College, Duntroon (RMC), the mission is to produce men and women who are capable and effective officers and soldiers. The weight of the pack with the items required at RMC is often in excess of 40 kg. In evaluating the effectiveness of current practice, this thesis takes an anthropometric perspective in exploring the historical, physiological and social context of current loads carried by Australian soldiers, It does not, however, evaluate the content of the load itself. Research methods include: a/. Systematic examination of past research findings on the social and physiological aspects of military load carrying since the Roman Centurions. b/. Biophysical tesing of nine soldiers, using a battery of physiological tests to determine heart rates and energy expenditure at various loads. c/. A survey of 100 soldiers from the Royal Military College, Duntroon and in-depth interviews with a sample of four experienced soldiers to obtain the views of the load carriers. The research concludes that the optimum approach to load carrying, and so to the design of the Army backpack, is that it be task-and soldier-specific. This runs directly counter to the longstanding Army traditions of preparing all soldiers for every possible contingency in battle and regarding all soldiers as equivalent units. The study findings offer some specific directions in which the design of the army backpack can be improved.Master of Science (Hons)
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Desai, Sheena Dhiksha. "The effect of load and technique on biomechanical and perceptual responses during dynamic pushing and pulling". Thesis, Rhodes University, 2009. http://hdl.handle.net/10962/d1005187.
Testo completoAbstract (sommario):
Changes in the industrial job profile, from lifting and lowering to repetitive dynamic pushing and pulling have been facilitated through the use of manual vehicles, aimed at minimising the workload. Yet, the demands of pushing and pulling have not been well documented. Using measures of the horizontal component of the hand forces, spinal kinematics, muscle activity at various sites on the upper body and body discomfort ratings, this study aimed at quantifying the biomechanical and perceptual demands of various dynamic push/pull techniques. 36 healthy male participants performed two-handed forward pushing, two-handed backward pulling and one-handed forward pulling, employing an industrial pallet jack supporting two loads of 250kg or 500kg. While no single technique was definitively identified as preferable regarding hand forces, pushing at 500kg elicited higher initial and sustained forces (p<0.05) than one- and two-handed pulling respectively. Increments in load mass from 250kg to 500kg resulted in significant differences in the initial, sustained and ending forces. With regard to spinal kinematics in the sagittal plane, two-handed pulling elicited the highest trunk flexion, and may therefore expose individuals to prolonged forward bending. Generally this technique was found to evoke the highest sagittal responses. Spinal kinematic measures in the lateral and transverse planes suggested that one-handed pulling was accompanied by the highest measures, and hence the greatest risk of developing lower back disorders related to this plane. Although various combinations of muscles were active during each technique, one-handed pulling and pushing, most often induced the highest muscle activation levels and two-handed pulling, the lowest. While erector spinae evidenced no significant differences between techniques at each load or between loads for the same technique, activation levels were high under all conditions. Perceptual ratings of body discomfort revealed that not only is the upper body susceptible to injuries during pushing and pulling, but also that the lower extremities may have a considerable role to play in these tasks, with the calves being a particular area of concern. Findings concluded that symmetrical pushing and pulling tasks are preferable.
17
Lehmann, Frederick Denis. "Weight load carry : a review of the efficiency and effectiveness of the army backpack /". View thesis, 1998. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20050810.122056/index.html.
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Wong, Man-ying, e 黃文英. "A manual handling operations training program for healthcare workers in preventing back pain and injury". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44626605.
Testo completo
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Pettengell, Clare Louise. "The isolation of muscle activity and ground reaction force patterns associated with postural control in four load manipulation tasks". Thesis, Rhodes University, 2010. http://hdl.handle.net/10962/d1005203.
Testo completoAbstract (sommario):
Although much effort has been placed into the reduction of risks associated with manual materials handling, risk of musculoskeletal disorder development remains high. This may be due to the additional muscle activity necessary for the maintenance of postural equilibrium during work tasks. This research proposes that postural control and subsequent additional muscle activity is influenced by the magnitude of the external load and the degree of body movement. The objective of this research was to identify whether performing tasks with increased external load and with a greater degree of trunk motion places additional strain on the musculoskeletal system in excess of that imposed by task demands. Twenty-four male and twenty-four female subjects performed four load manipulation tasks under three loading conditions (0.8kg, 1.6kg, and 4kg). Each task comprised of a static and dynamic condition. For the static condition, subjects maintained a stipulated posture for ten seconds. The dynamic condition required subjects to move and replace a box once every three seconds, such that a complete lift and lower cycle was performed in six seconds. Throughout task completion, muscle activity of six pairs of trunk muscles were analysed using surface electromyography. This was accompanied by data regarding ground reaction forces obtained through the use of a force platform. After the completion of each condition subjects were required to identify and rate body discomfort. Differential analysis was used to isolate the muscle activity and ground reaction forces attributed to increased external load and increased trunk movement. It was found that the heaviest loading conditions (4kg) resulted in significantly greater (p<0.05) muscle activation in the majority of muscles during all tasks investigated. The trend of muscle activity attributed to load was similar in all significantly altered muscles and activation was greatest in the heaviest loading condition. A degree of movement efficiency occurred in some muscles when manipulating loads of 0.8kg and 1.6kg. At greater loads, this did not occur suggesting that heavier loading conditions result in additional strain on the body in excess of that imposed by task demands. In manipulated data, trend of vertical ground reaction forces increased with increased load in all tasks. Sagittal movement of the centre of pressure attributed to load was significantly affected in manipulated data in the second movement phase of the “hip shoulder” task and the second movement phase of the “hip twist” task. The “hip reach” task was most affected by increased load magnitude as muscle activity attributed to load was significantly different (p<0.05) under increased loading conditions in both movement phases in all muscles. Further, a significant interactional effect (p<0.05) between condition and data point was found in all muscles with the exception of the right and left lumbar erector spinae during the second movement phase of the “hip reach” task. Muscle activity associated with increased trunk motion resulted in additional strain on the trunk muscles in the “hip shoulder” and “hip reach” tasks as muscle activity associated with the static component of each of the above tasks was greater than that of the dynamic tasks. Trend of ground reaction forces attributed to increased trunk motion generally increased under increased loading conditions. Additionally, a significant interactional effect (p<0.05) between load and muscle activity pattern was found in all muscles during all tasks, with the exception of the right rectus abdominis in the first movement phase of the “hip shoulder’ task, the left rectus abdominis in the second movement phase of the “hip knee” task and the right latissimus dorsi during the first movement phase of the “hip twist” task. This was accompanied by a significant interactional effect (p<0.05) between load and sagittal centre of pressure movement attributed to load, in both movement phases of all tasks investigated. From this research it can be proposed that guidelines may underestimate risk and subsequently under predict the strain in tasks performed with greater external loads as well as tasks which require a greater degree of trunk motion. Therefore, this study illustrates the importance of the consideration of the muscle activity necessary to maintain postural equilibrium in overall load analyses.
20
Furney, Sheena Elizabeth. "Laboratory investigation of a load carriage task observed in forestry". Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1008188.
Testo completoAbstract (sommario):
The objective of the present study was to investigate and compare the human responses to two load carriage tasks performed with three different load masses and on three different gradients. The task of carrying hydrogel in one hand was observed in a silviculture industry and crude physiological and perceptual responses were measured. This task was simulated in a laboratory setting together with a suggested intervention of backpack carriage. Eighteen conditions were established which consisted of the two modes of carriage and a combination of three load masses (9kg, 12kg and 15kg) and three gradients (5%, 10% and 15%). Twenty eight Rhodes University female students comprised the sample and the experimental procedures were conducted on a Quinton treadmill. Each participant was required to complete nine of the eighteen conditions which were each four minutes in duration. Postural changes were assessed using lateral and posterior digital images taken at the second and fourth minute and compression and shearing forces were estimated with the ErgolmagerTM Physiological responses (heart rate, ventilation and metabolic responses) were measured continuously with the Quark b² and perceptual responses ('central' and 'local' RPE) were measured every minute during the experimentation and body discomfort was rated at the completion of each condition. Overall responses revealed that hand carriage (146 bt.min⁻¹ , 25.09 mIO₂. kg-l.min⁻¹) was generally found to be more physiologically stressful than backpack carriage (130 bt.min⁻¹, 22.15 mIO₂.kg⁻¹ .min⁻¹) independent of load mass and gradient. Physiological responses were higher (113 bt.min-1 to 174 bt.min⁻¹ ) in responses to increasing gradient as opposed to increasing load mass (104 bt.min-1 to 153 bt.min⁻¹ ) for both backpack and hand carriage. Categorisation using the guidelines of Sanders and McCormick (1993) allowed for classification of conditions, with respect to physiological responses, into 'moderate', 'heavy' and 'very heavy' stress. For almost all of the physiological responses the majority of conditions which were classified as 'moderate' were backpack carriage conditions and the conditions classified as 'very heavy' were mostly hand carriage conditions. In terms of postural responses hand carriage resulted in more strain and greater compression and shearing forces on the spine. In terms of the compression forces increasing gradient had a greater affect on backpack carriage (681 N to 935 N) compared to hand carriage (570N to 793N). In contrast, increasing load mass had a larger affect on hand carriage postures and compression forces (751 N to 935N) in comparison to backpack carriage (723N to 780N). Shearing forces were found to be worse in hand carriage conditions overall. Although participants generally underrated perceived exertion in relation to cardiorespiratory responses, these perceptions revealed that backpack carriage, with a mean 'central' RPE of 12 compared to 11 for hand carriage, was somewhat preferred to hand carriage and that increasing gradient was perceived to be marginally more straining than increasing load mass.
21
Lu, Kui. "A comparison of infant-carrying methods with physical stress in Hong Kong Chinese female adults". HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/602.
Testo completo
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Choi, Chun-yeung, e 蔡振揚. "A generic fatigue model for frequently performed, highly repetitive combined material handling". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B37841464.
Testo completo
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Ramabhai, Leena I. "The effect of load carriage on selected metabolic and perceptual responses of military personnel". Thesis, Rhodes University, 2000. http://hdl.handle.net/10962/d1005189.
Testo completoAbstract (sommario):
Taking a multi-disciplinary, integrated approach, the present study sought to examine selected physiological and psycho-physical parameters related to load carriage involving a 12 km march under military conditions. Military constraints hampered, but did not entirely inhibit the secondary aim of the study which concerned the effectiveness of relativising loads in order to normalise responses for all soldiers, irrespective of morphological diversity. Forty three subjects were measured in six groups using a test-retest experimental protocol. They were involved in a rest-broken 12 km march at 4 km.h⁻¹ under 40.5 kg absolute total load and under a relative load of 37% of body mass. Heart rates, ratings of perceived exertion (RPE) as well as area and intensity of discomfort were monitored for all subjects. Ten subjects were measured more extensively with regard to physiology using the Metamax, a portable ergospirometry system that provides all the data needed for a complete functional analysis of lung, heart, circulation and metabolic activity. Physiological responses (fc; fb; V̇T; V̇E; V̇O₂; EE; V̇CO₂; R; T°) indicated subjects were not severely physically taxed and that the loads imposed constituted a sub-maximal demand. Moreover, there appeared to be a limited cumulative effect over the 3.5 h. Data from the first and third hours were similar, while the significantly higher responses in the second hour reflected the challenge of the undulating terrain encountered during this section of the march. All responses during the Relative load conditions mirrored those of the Absolute load condition but, because the demands were less, the trends occurred at a reduced level. Furthermore, the reduction in inter-individual variability indicates that relativised load carriage tends to stress the soldiers in a more uniform manner. All "local" RPE responses were higher than "central" ratings, suggesting soldiers were in good cardiovascular condition and experienced marginally more strain in the lower limbs. There was increased perceived strain corresponding to the increase in gradient, with little cumulative effect over the three hours. The shoulders and feet were the two regions in which most discomfort was experienced; the shoulders being the worst area in the first hour and the feet being rated the worst after the third hour of marching. This study clearly demonstrates the probability of a significant improvement in mean combat-readiness following loaded marching by showing that, if loads are set at levels commensurate with individual capabilities to carry them without undue strain, unnecessary physical demands experienced by smaller, more gracile soldiers are reduced.
24
Ravelo, Emilio M. "Theoretical Basis for General Mixed Object Handling Equations Based on Mechanical Work Required". University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1100641006.
Testo completo
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Walraven, Lynne Louise. "Identification and analysis of manual materials handling tasks within a commercial warehouse in South Africa". Thesis, Rhodes University, 1989. http://hdl.handle.net/10962/d1015722.
Testo completoAbstract (sommario):
Lifting and overstraining are major causative factors related to musculoskeletal injuries and low back pain. A great number of work-related injuries arise from the handling and/or mishandling of materials. Hence there is a need to quantify risk factors in situ and develop guidelines for safe lifting practises in industry. The aim of this study was to make appropriate in situ quantification, within a commercial warehouse, of the stresses and physical demands imposed on the worker when performing two handed lifts in the sagittal plane. The performance of employees was assessed under normal working conditions through an observational methodology of data collection. Task performance evaluation was based on detailed measurement of all containers handled, an activity and time analysis, and the 'Work Practices Guide to Manual Lifting’ (NIOSH, 1981) which was used as the primary guide to developing theoretical recommendations to probable MMH risk factors for the workers involved. Of the 191 tasks analysed 103 were deemed unsuitable. Appropriate task factor adjustments were made where necessary to both the frequency and Hfactors (horizontal distance between the centre of gravity of the container and that of the worker) in order to reduce the risk factor for the workers
26
Muriti, Andrew John Safety Science Faculty of Science UNSW. "A biomechanical analysis of patient handling techniques and equipment in a remote setting". Awarded by:University of New South Wales. Safety Science, 2005. http://handle.unsw.edu.au/1959.4/22002.
Testo completoAbstract (sommario):
Remote area staff performing manual patient handling tasks in the absence of patient lifting hoists available in most health care settings are at an elevated risk of musculoskeletal injuries. The objective of this project was to identify the patient handling methods that have the lowest risk of injury. The patient handling task of lifting a patient from floor to a chair or wheelchair is a common task performed in a remote health care setting. The task was performed utilising three methods, these being: (1) heads/tails lift, (2) use of two Blue MEDesign?? slings and (3) use of a drawsheet. The task of the heads/tails lift was broken down into two distinctly separate subtasks: lifting from the (1) head and (2) tail ends of the patient load. These techniques were selected based on criteria including current practice, durability, portability, accessibility, ease of storage and cost to supply. Postural data were obtained using a Vicon 370 three - dimensional motion measurement and analysis system in the Biomechanics & Gait laboratory at the University of New South Wales. Forty reflective markers were placed on the subject to obtain the following joint angles: ankle, knee, hip, torso, shoulder, elbow, and wrist. The raw data were converted into the respective joint angles (Y, X, Z) for further analysis. The postural data was analysed using the University of Michigan???s Three-Dimensional Static Strength Prediction Program (3D SSPP) and the relative risk of injury was based on the following three values: (1) a threshold value of 3,400 N for compression force, (2) a threshold value of 500 N for shear force, and (3) population strength capability data. The effects on changes to the anthropometric data was estimated and analysed using the in-built anthropometric data contained within the 3D SSPP program for 6 separate lifter scenarios, these being male and female 5th, 50th and 95th percentiles. Changes to the patient load were estimated and analysed using the same computer software. Estimated compressive and shear forces were found to be lower with the drawsheet and tail component of the heads/tails lift in comparison to the use of the Blue MEDesign?? straps and head component of the heads/tails lift. The results obtained for the strength capability aspect of each of the lifts indicated a higher percentage of the population capable of both the drawsheet and tail end of the heads/tails lift. The relative risk of back injury for the lifters is distributed more evenly with the drawsheet lift as opposed to the heads/tails (tail) lift where risk is disproportionate with the heavier end being lifted. The use of lifter anthropometrics does not appear to be a realistic variable to base assumptions on which group of the population are capable of safely performing this task in a remote setting. This study advocates the use of the drawsheet lift in a remote setting based on the author???s experience and the biomechanical results obtained in this study. The drawsheet lift is both more accessible and provides a more acceptable risk when more than two patient handlers are involved, in comparison to the other lifts utilised lifting patients from floor to a chair.
27
Bennett, Anthea Iona. "The effect of load and technique on biomechanical and psychophysical responses to level dynamic pushing and pulling". Thesis, Rhodes University, 2009. http://hdl.handle.net/10962/d1005188.
Testo completoAbstract (sommario):
Pushing and pulling research has yet to fully elucidate the demands placed on manual workers despite established epidemiological links to musculoskeletal disorders. The current study therefore aimed to quantify biomechanical and perceptual responses of male operators to dynamic pushing and pulling tasks. Three common push/pull techniques (pushing, one handed and two handed pulling) were performed at loads of 250kg and 500kg using an industrial pallet jack in a laboratory environment. Thirty six healthy male subjects (age: 21 ±2 years, stature: 1791 ±43 mm and body mass: 77 ±10 kg) were required to perform six loaded experimental and two unloaded control conditions. Hand force exertion, muscle activity and gait pattern responses were collected during 10m push/pull trials on a coefficient controlled walkway; body discomfort was assessed on completion of the condition. Horizontal hand force responses were significantly (p<0.05) affected by load, with a linear relationship existing between the two. This relationship is determined by specific environmental and trolley factors and is context specific, depending on factors such as trolley maintenance and type of flooring. Hand force exertion responses were tenuously affected by technique at higher loads in the initial and sustained phases, with pushing inducing the greatest hand forces. Comparison of the motion phases revealed significant differences between all three phases, with the initial phase evidencing the greatest hand forces. Muscle activity responses demonstrated that unloaded backward walking evoked significantly higher muscle activation than did unloaded forward walking whilst increased muscular activity during load movement compared to unloaded walking was observed. However increasing load from 250kg to 500kg did not significantly impact the majority of muscle activity responses. When considering technique effects on muscle activity, of the significant differences found, all indicated that pushing imposed the least demand on the musculoskeletal system. Gait pattern responses were not significantly affected by load/technique combinations and were similar to those elicited during normal, unloaded walking. Perceptually, increased load led to increased perception of discomfort while pushing resulted in the least discomfort at both loads. From these psychophysical responses, the calves, shoulders and biceps were identified as areas of potential musculoskeletal injury, particularly during one and two handed pulling. Pushing elicited the highest hand forces and the lowest muscle activity responses in the majority of the conditions whilst psychophysical responses identified this technique as most satisfactory. Current results advocate the use of pushing when moving a load using a wheeled device. Suitability of one and two handed pulling remains contradictory, however results suggest that one handed pulling be employed at lower loads and two handed pulling at higher loads.
28
POLIERO, TOMMASO. "Enhancing Occupational Back-Support Exoskeletons Versatility". Doctoral thesis, Università degli studi di Genova, 2021. http://hdl.handle.net/11567/1045128.
Testo completoAbstract (sommario):
In the 1970s, the scientific community began addressing the relationship between musculoskeletal disorders (MSDs) and work ergonomics. Since then, many studies have been published regarding this topic. Yet, 50 years later, MSDs are still cited as the most common work-related health problem, in the majority of the cases due to back pain. Workers performing manual material handling (MMH) activities (e.g., package loading and unloading in a warehouse or luggage handling in airports) are among the most exposed to risks and injuries. Several solutions have been proposed but, due to high implementation costs or lack of acceptability by the workers, MSD problem has not been solved.
Occupational back-support exoskeletons have been investigated for their ability to reduce muscle activation and, hence, mitigate the risk of injuries. Exoskeletons can be categorized as soft or rigid, if how the assistance is delivered to the user is taken into account, or as active, passive or quasi- passive, if, instead, focus is on the actuators that generate the assistance. Regardless of the categories, exoskeletons have been designed and tested, mostly, for static bending or lifting tasks. This is justified by the high risk of developing injuries associated with these tasks, but, on the other hand, does not address the complexity that out-of-the-lab environments might present. In this regard, an interesting study reported that if passive exoskeletons are used in non-lifting tasks, as walking, rather than helping they actually hinder and obstacle the wearers’ movements. And, it is clear, that in industrial settings, workers do not lift for the whole duration of their schedule. Other relevant activities might be pushing, pulling or carrying. Indeed, the International Standard ISO 11228 establishes ergonomic guidelines also for these activities, highlighting that they could yield risk of injuries. Therefore, designing exoskeletons that address also these activities might help promote the acceptability of these devices.
In this work, exoskeleton versatility is defined as the device ability to recognize which activity the user is performing and provide assistance accordingly. As an example, assisting with lifting could require the design of strategies that are not fit for carrying assistance. More in details, in the first part of this thesis, it is shown that considering spinal loading, carrying has an impact comparable to that of lifting. However, if lifting control strategies are used to assist with carrying, this produces gait impairments. The need of assisting with these two activities in different ways requires, first of all, a mean to recognize which task is taking place. This is addressed in the second part of the thesis. In particular, by using Support Vector Machines (SVM), it is shown that it is possible to build an automatic Human Activity Recognition (HAR) algorithm. Moreover, this algorithm can be embedded in the control architecture of XoTrunk, the back-support exoskeleton developed at our lab, enhancing its versatility. The third and last part of this this work assesses the advantages of using a versatile exoskeleton, comparing its performance to state-of-the-art exoskeletons and control strategies. At the end of the work, it is described the impact that exoskeleton versatility had on field testing.
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Dell, Geoff University of Ballarat. "The causes and prevention of airline baggage handler back injuries : safe designs required where behaviour and administrative solutions have had limited effect". University of Ballarat, 2007. http://archimedes.ballarat.edu.au:8080/vital/access/HandleResolver/1959.17/12823.
Testo completoAbstract (sommario):
"Back injuries have consistently been the most common types of injuries suffered by people at work. They have been a significant worker injury problem in most, if not all, industrialised countries for many years and manual handling has long been established as a significant task related back injury causal factor.[...] This research project established that the manufacturers of the jet airlines used by the airlines in this study had not previously been acquainted with the issue of baggage handler back injuries.[...] This study also canvassed the opinion of airline safety professionals and airline baggage handlers concerning baggage handling tasks and working environment related causal factors. [...] A major focus of this research project was also to measure the effect of ACE and Sliding Carpet, two commercially available retro-fit baggage systems, on the risk of back injuries to baggage handlers stacking baggage within Boeing B737 narrow-body aircraft."Doctor of Philosophy
30
Dell, Geoff. "The causes and prevention of airline baggage handler back injuries : Safe designs required where behaviour and administrative solutions have had limited effect". Thesis, University of Ballarat, 2007. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/44427.
Testo completoAbstract (sommario):
"Back injuries have consistently been the most common types of injuries suffered by people at work. They have been a significant worker injury problem in most, if not all, industrialised countries for many years and manual handling has long been established as a significant task related back injury causal factor.[...] This research project established that the manufacturers of the jet airlines used by the airlines in this study had not previously been acquainted with the issue of baggage handler back injuries.[...] This study also canvassed the opinion of airline safety professionals and airline baggage handlers concerning baggage handling tasks and working environment related causal factors. [...] A major focus of this research project was also to measure the effect of ACE and Sliding Carpet, two commercially available retro-fit baggage systems, on the risk of back injuries to baggage handlers stacking baggage within Boeing B737 narrow-body aircraft."Doctor of Philosophy
31
Dell, Geoff. "The causes and prevention of airline baggage handler back injuries : safe designs required where behaviour and administrative solutions have had limited effect". University of Ballarat, 2007. http://archimedes.ballarat.edu.au:8080/vital/access/HandleResolver/1959.17/14622.
Testo completoAbstract (sommario):
"Back injuries have consistently been the most common types of injuries suffered by people at work. They have been a significant worker injury problem in most, if not all, industrialised countries for many years and manual handling has long been established as a significant task related back injury causal factor.[...] This research project established that the manufacturers of the jet airlines used by the airlines in this study had not previously been acquainted with the issue of baggage handler back injuries.[...] This study also canvassed the opinion of airline safety professionals and airline baggage handlers concerning baggage handling tasks and working environment related causal factors. [...] A major focus of this research project was also to measure the effect of ACE and Sliding Carpet, two commercially available retro-fit baggage systems, on the risk of back injuries to baggage handlers stacking baggage within Boeing B737 narrow-body aircraft."Doctor of Philosophy
32
Shuman, Barbara Dixon. "The effect of backpack weight on the height of middle school students". CSUSB ScholarWorks, 2003. https://scholarworks.lib.csusb.edu/etd-project/2172.
Testo completoAbstract (sommario):
The focus of this study investigates the effect backpack weight has on the height of middle school students. It provides data about the effects of backpack weight on height that has not previously been determined. This study aims to contribute information to a growing body of evidence which supports the limitation of backpack weight for children to be no more than 10% of body weight.
33
Van, Blommestein Donald Lloyd. "Automating a labour performance measurement and risk assessment: an evaluation of methods for a computer vision based system". Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86502.
Testo completoAbstract (sommario):
Thesis (MScEng) Stellenbosch University, 2014ENGLISH ABSTRACT: This thesis brings together productivity and risk assessments through innovative design, development and evaluation of a unique system for retrieving and analysing data. In the past, although the link between them is well-documented, these assessments have largely been dealt with as separate antagonist entities. A broad evaluation of the existing traditional and technological support systems has been conducted to identify suitable methodologies along with a common technological platform for automation. The methodologies selected for the productivity and risk assessments were; work sampling and the revised NIOSH lifting equation respectively. The automation of these procedures is facilitated through computer vision and the use of a range imaging Kinect™ camera. The standalone C++ application integrates two tracking approaches to extract real-time positional data on the worker and the work-piece. The OpenNI and OpenCV libraries are used to perform skeletal tracking and image recognition respectively. The skeletal tracker returns positional data on specific joints of the worker, while the image recognition component, a SURF implementation, is used to identify and track a specific work-piece within the capture frame. These tracking techniques are computationally expensive. In order to enable real time execution of the program, Nvidia’s CUDA toolkit and threading building blocks have been applied to reduce the processing time. The performance measurement system is a continuous sampling derivative of work sampling. The speed of the worker’s hand movements and proximity to the work-piece are used to classify the worker in one of four possible states; busy, static, idle, or out of frame. In addition to the worker based performance measures, data relating to work-pieces are also calculated. These include the number of work-pieces processed by a specific worker, along with the average and variations in the processing times. The risk assessment is an automated approach of the revised NIOSH lifting equation. The system calculates when a worker makes and/or breaks contact with the work-piece and uses the joint locations from the skeletal tracker to calculate the variables used in the determination of the multipliers and ultimately the recommended weight limit and lifting index. The final calculation indicates whether the worker is at risk of developing a musculoskeletal disorder. Additionally the information provided on each of the multipliers highlights which elements of the lifting task contribute the most to the risk. The user-interface design ensures that the system is easy to use. The interface also displays the results of the study enabling analysts to assess worker performance at any time in real time. The automated system therefore enables analysts to respond rapidly to rectify problems. The system also reduces the complexity of performing studies and it eliminates human errors. The time and costs required to perform the studies are reduced and the system can become a permanent fixture on factory floors. The development of the automated system opens the door for further development of the system to ultimately enable more detailed assessments of productivity and risk.
AFRIKAANSE OPSOMMING: Produktiwiteit en risiko evaluerings word in hierdie tesis saam hanteer deur die innoverende ontwerp, ontwikkeling en evaluering van 'n unieke stelsel vir die meting en ontleding van data. Alhoewel die skakel tussen hulle goed gedokumenteer is, word hierdie evaluering as afsonderlike antagonistiese entiteite hanteer. 'n Breë studie van die bestaande tradisionele en tegnologiese ondersteuningstelsels is gedoen om toepaslike metodes te identifiseer, om 'n gemeenskaplike tegnologiese platform vir outomatisering daar te stel. Die metodes wat gekies is vir die produktiwiteit en risiko bepalings is onderskeidelik werk monsterneming en die hersiende NIOSH opheffing vergelyking. Die outomatisering van hierdie prosedures word gefasiliteer deur middel van rekenaar visie en die gebruik van 'n Kinect™ 3D kamera. Die selfstandige C++ program integreer ‘n dubbelvolgings benadering om in reële tyd posisionele data van die werker en die werk-stuk te kry. Die OpenNI en OpenCV biblioteke word onderskeidelik gebruik om skeletale volging en beeld erkenning uit te voer. Die skeletale volger bepaal posisionele data van spesifieke gewrigte van die werker, terwyl die beeld erkenning komponent, 'n SURF implementering gebruik om 'n spesifieke werk-stuk binne die opname raam te identifiseer en te volg. Hierdie volgings tegnieke is berekenings intensief. Om werklike tyd uitvoering van die program te verseker, is Nvidia se CUDA gereedskapstel en liggewig boublokke geimplementeer. Die produktiwiteit meting-stelsel is 'n aaneenlopende monsterneming benadering van werk monsterneming. Die spoed van die werker se handbewegings en nabyheid aan die werkstuk word gebruik om die werker te klassifiseer as in een van vier moontlike toestande; besig, staties, onaktief of buite die raam. Benewens die werker gebaseerde metings, word daar ook data oor werkstukke bereken. Dit sluit in die aantal werkstukke verwerk deur 'n spesifieke werker, sowel as die gemiddelde en variasie in verwerkings tye. Die risiko-berekening is 'n outomatiese benadering van die hersiende NIOSH opheffing vergelyking. Die stelsel bereken wanneer die werker kontak maak en/of breek met die werkstuk en maak gebruik van die gewrigsposisies wat die skeletale volger aandui om die veranderlikes wat in die vermenigvuldigers gebruik word te bepaal. Die vermenigvuldigers word gebruik om die aanbevole maksimum gewig en die opheffing indeks te bereken. Die opheffing indeks dui aan of daar ‘n risiko vir die werker is om muskuloskeletale versteuring te ontwikkel. Benewens dui die vermenigvuldigers aan watter elemente die grootste bydra tot die risiko van die opheffingstaak maak. Die gebruiker-koppelvlak-ontwerp verseker dat die stelsel maklik is om te gebruik. Die koppelvlak vertoon ook die resultate van die studie sodat ontleders op enige tyd werker prestasie kan evalueer in reële tyd. Die outomatiese stelsel stel dus ontleders in staat om vinnig te reageer sodat probleme reggestel kan word. Die stelsel verminder ook die kompleksiteit vir die uitvoering van studies en dit elimineer menslike foute. Die tyd en koste vereis om die studie te doen, word verminder en die stelsel kan ‘n permanente instelling op fabriekvloere geword. Die ontwikkeling van die outomatiese stelsel maak die deur oop vir verdere ontwikkeling van die stelsel om uiteindelik daartoe te lei dat meer gedetailleerde evaluering van produktiwiteit en risiko bepaal kan word.
34
Bassey-Duke, Elizabeth Misan. "An ergonomics intervention study into the physiological, perceptual and productivity effects of three citrus harvesting bag designs in the Eastern Cape of South Africa : a combined laboratory and field approach". Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1018908.
Testo completoAbstract (sommario):
Background: Agriculture plays a vital role in the economy of any industrially developing country, including South Africa. In the Eastern Cape of South Africa citrus farming is a significant contributor to the local economy (Johnson et al., 2005). The harvesting phase of citrus farming is performed manually and exposes workers to physical risks, which can lead to the development of musculoskeletal disorders. In particular, the standard harvesting bag comprises of a single shoulder strap and promotes asymmetrical load carriage which results in shoulder and lower back pain complaints. The current study compared the physiological (EMG), perceptual (RPE), usability (PUEU) and productivity effects of two new harvesting bag designs (a hip belt and a backpack bag design) to the standard harvesting bag design. This was performed in a laboratory as well as a field setting. Methods (Laboratory phase): 36 participants (12 males and 24 females) were assigned to one worker group. The “tall ladder worker” group was comprised of only males and the “step ladder worker” and “ground worker” group of females. Each participant was required to simulate a citrus harvesting task while utilizing each of the bag designs on different days. On each day/test session, participants performed three harvesting cycles. Muscle activity was measured throughout the entire testing session and RPE were recorded at the end of each cycle. Results (Laboratory phase): The EMG and RPE results indicate that the backpack design was the most ideal design to reduce asymmetry, while the standard harvesting bag design was the worst. Although not significant, there was greater muscle asymmetry (p=0.109) and a significantly higher perceived exertion when using the standard bag (p=0.0004), in comparison to using the backpack. Methods (Field phase): 17 Xhosa-speaking citrus harvesters (6 females and 11 males) participated in this study. Each harvester worked with one of the three bag designs on a different day. Productivity of each worker was assessed every hour by recording the number of bags filled with fruit and at the end of the shift. A Perceived Usefulness & Ease of Use questionnaire was presented to each participant to obtain feedback on worker acceptance to the new bag designs. Results (Field phase): A general trend in support of the hip belt bag design over the other two bag designs were found, even within the different worker demographic groups (age, sex and worker experience). The workers perceived less exertion (7.98 ± 1.86) and were more productive (9.90 ± 2.11 bags/hour) when using the hip belt design; they also found this bag the most useful (1.02 ± 0.09) and easy to use (1.07 ± 0.25). In contrast, the backpack bag design had significantly poorer responses when compared to the other two bag designs and this was evident in all the dependent variables assessed (RPE, productivity and PUEU). Conclusion: The results from the laboratory phase supported the expectation that the backpack bag design reduces asymmetry and hence, is more suitable than the standard harvesting bag. However, results from the field show that the hip belt bag design was the most preferred and the backpack was the least preferred. Bao & Shahnavaz (1989) highlight the need for ergonomics researcher to convey laboratory findings into the field context. However, as shown by the current study, there are numerous challenges associated with field work, making it difficult for laboratory findings to be successfully conveyed to the field. Limitations and Recommendations: For the laboratory phase of the project, no biomechanical and cardiovascular responses were assessed. However, for a holistic approach, these variables should be considered in future studies. Due to high variability from one harvesting cycle to another, more than three harvesting cycles should also be performed to accurately replicate the harvesting process as done in the field over extended durations of time. For the field phase, data should be collected from more than one citrus farm and thus a larger sample size could be obtained. This would improve the validity of the study. In addition to this, data should be collected for a full working day, especially if environmental conditions are not a hindrance, as well as for a whole season, since workloads vary, depending on the time of the harvesting season.Name on Graduation Programme: Bassey-Duke, Elizabeth Missan
35
Elliott, Andrew Brent. "Risk assessment and the effects of overhead work - an automotive industry example". Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1005211.
Testo completoAbstract (sommario):
The focus of this investigation was an analysis of the work demands being placed on South African automotive industry workers as there is a recognised problem with regard to the prevalence of musculoskeletal disorders (MSDs). Preliminary work was conducted to highlight the dominant risks and areas which elicited higher numbers of MSDs within the chosen automotive plant. An area of concern was highlighted through medical record analysis and the use of risk assessment tools, thereby prioritising the need for ergonomic intervention. In particular, the effects of varying restricted and overhead work heights on the biomechanical, physiological and psychophysical responses of an individual were investigated. Twenty-eight subjects were required to complete sixteen conditions. The conditions consisted of the adoption of restricted and upright overhead static postures, with half requiring the holding of four kilograms of weight in the hands and the remaining eight conditions having no weight. Testing was carried out using an electromyography unit, ergospirometer and a perceptual Body Discomfort Map and Scale. This involved a habituation and testing session. The results of the testing revealed the biomechanical and physiological responses were dependant on the change in height. Body discomfort was also shown to be variable over the changing height conditions. This indicates that there is a significant effect of height on an individual’s responses during overhead work. The extreme restricted (-200mm and -100mm) and upright (+300mm and +400mm) overhead conditions within this study were limiting, as they elicited the highest muscle activation, physiological responses and body discomfort ratings. Positions that are preferable to adopt, which were identified from the results in this study, indicate conditions closer to head height (0mm and +100mm) were favourable. The results therefore illustrate how awkward working postures during work are likely to elicit higher demands from an individual, which could lead to an increased risk for the development of a musculoskeletal disorder. The added factor of weight elicited significant results over all variables, excluding a respiratory The focus of this investigation was an analysis of the work demands being placed on South African automotive industry workers as there is a recognised problem with regard to the prevalence of musculoskeletal disorders (MSDs). Preliminary work was conducted to highlight the dominant risks and areas which elicited higher numbers of MSDs within the chosen automotive plant. An area of concern was highlighted through medical record analysis and the use of risk assessment tools, thereby prioritising the need for ergonomic intervention. In particular, the effects of varying restricted and overhead work heights on the biomechanical, physiological and psychophysical responses of an individual were investigated. Twenty-eight subjects were required to complete sixteen conditions. The conditions consisted of the adoption of restricted and upright overhead static postures, with half requiring the holding of four kilograms of weight in the hands and the remaining eight conditions having no weight. Testing was carried out using an electromyography unit, ergospirometer and a perceptual Body Discomfort Map and Scale. This involved a habituation and testing session. The results of the testing revealed the biomechanical and physiological responses were dependant on the change in height. Body discomfort was also shown to be variable over the changing height conditions. This indicates that there is a significant effect of height on an individual’s responses during overhead work. The extreme restricted (-200mm and -100mm) and upright (+300mm and +400mm) overhead conditions within this study were limiting, as they elicited the highest muscle activation, physiological responses and body discomfort ratings. Positions that are preferable to adopt, which were identified from the results in this study, indicate conditions closer to head height (0mm and +100mm) were favourable. The results therefore illustrate how awkward working postures during work are likely to elicit higher demands from an individual, which could lead to an increased risk for the development of a musculoskeletal disorder. The added factor of weight elicited significant results over all variables, excluding a respiratory individual.
36
Duguid, Lynn. "The use of backpacks, levels of physical activity and reported pain in Year 8 school students /". 1998. http://arrow.unisa.edu.au:8081/1959.8/85263.
Testo completo
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Desai, Sheena Dhiksha. "The effect of load and technique on biomechanical and perceptual responses during dynamic pushing and pulling /". 2008. http://eprints.ru.ac.za/1572/.
Testo completo
38
Lean, Leonard. "Lifting devices used by hospital staff; their relationship to the handling of patients". Thesis, 1991. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/97539.
Testo completoAbstract (sommario):
This paper investigates the utilisation of lifting devices by hospital staff, in relation-ship to the handling of patients and the reasons for this. A survey was conducted at Flinders Medical Centre, Adelaide during June and July 1989 using a questionnaire which returned 54% (n=110) completed returns. The results showed a lack of available lifting devices; 16.4% (n=18) of health care respondents had no lifting devices available in their work area while 14.5% (n=16) of respondents had only one lifting device. Where lifting devices were available, 63.6% (n=70) of respondents used the lifting devices less than three times in the week prior to the survey. 24.6% (n=27) of respondent health care workers were of the opinion that lifting devices were not very appropriate for patient handling tasks and 12.7% (n=14) of respondents found the devices difficult to use. 22.7% (n=25) of respondents indicated insufficient room for the use of the devices. 19.1% (n=21) of respondents consider the floor plan layout in which they to be utilised obstructive. 24.5% (n=27) were of respondents found that the lifting devices were not very mobile. 24.6% (n=27) of respondents considered that the setting-up time of the lifting devices took too long and 18.2% (n=20) were of the opinion that the devices were located too far away from the workplace for quick and convenient access. Strong emphasis in the literature review is placed on Common and Statute Law of the employer's "Duty of Care" to the health care workers. The main recommendation is that users need to have input into the design of the equipment. Also, user require initial training and require on-going refresher training in the use of lifting devices for patients. Supervision of users of lifitng devices is essential.Thesis (Master of Applied Science )
39
DeBeliso, Mark. "The effects of a lumbar support belt on radiographic characteristics of the lumbosacral spine". Thesis, 1997. http://hdl.handle.net/1957/33802.
Testo completoAbstract (sommario):
Study Design. This study investigated the effects of a lumbar support belt on lumbar disc deformation and joint angles. Trunk strength and endurance were also compared to disc deformation and joint angles to determine if any meaningful relationships existed.
Objective. The purpose of this study was to determine if back support belts relieve stresses encountered by the lumbar spine during lifting activities and thus reduce the risk of injury. Additionally, trunk strength and endurance measures were collected in order to determine if strong, well conditioned trunk musculature aids in the support of the lumbar spine.
Summary of Background Data. Low-back pain and injury are responsible for a major portion of lost work days and injury compensation claims. Back support belts have been proposed as a counter measure towards reducing low-back injuries in the industrial setting.
Methods. Twelve male subjects (average age, 49.7 years) performed two sessions of stoop type lifting with a loaded milk crate (11.5 kg), at a rate of 4 repetitions per minute, for a total 15 minutes per session in accordance with the NIOSH 1993 lifting
equation. The order of testing with and without a belt was randomized for the two
sessions. Fluoroscopic images were collected prior to and following both lifting sessions.
Fluoroscopic images were collected with the subjects positioned at the initiation (flexed
trunk), mid-range, and completion of the lift (erect standing). Images were imported into
Auto Cad where lumbar disc deformation and joint angles were measured by calculating
changes in position of adjacent vertebra (L3-4 and L4-5). A reduction of deformation was
deemed indicative of reduced stress. Trunk extension and flexion strength were measured
with a Kin Com isokinetic dynamometer. Trunk flexion endurance was measured via a 60
second curl-up test.
Results. Analysis of variance revealed that compressive and shear disc deformation were reduced while in the erect trunk posture for the support belt condition (p<.05). No significant reduction in disc deformation was detected while in flexed trunk postures for the support belt condition (p>.05). A significant inverse relationship was detected (p<05) between: abdominal strength and shear stress (flexed trunk positions), abdominal endurance and shear stress (erect trunk), and spinal erector strength and L4-L5
joint angle (erect trunk).
Conclusions. During stoop type lifting, support belts provide a measurable amount of stress reduction of the lumbar spine when the trunk is in the erect posture, with little effect during flexed trunk positions. Strong, well conditioned trunk musculature is associated with reduced stress on the lumbar spine.Graduation date: 1998
40
Noone, Gregory P. "Biomechanical modelling of some musculo-skeletal problems / by Gregory P. Noone". Thesis, 1993. http://hdl.handle.net/2440/21194.
Testo completoAbstract (sommario):
Copies of author's previously published articles inserted at backBibliography: leaves 211-220
viii, 220 leaves : ill ; 30 cm.
Summary: Investigates various problems relating to scoliosis and manual load handling. Introduces the idea of deducing optimal load lifting techniques which take into into account multiple joint/muscle complexes
Thesis (Ph.D.)--University of Adelaide, Dept. of Applied Mathematics, 1994
41
Bennett, Anthena Iona. "The effect of load and technique on biomechanical and psychophysical responses to level dynamic pushing and pulling /". 2008. http://eprints.ru.ac.za/1580/.
Testo completo
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郭俊宏. "The Changes on Skills and Capacity of Lifting and Carrying of High School Students with Mental Retardation after A Lifting and Carry Training Program: A Pilot Study". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/43665333910451798204.
Testo completo
43
Holmes, Michael W. R. "Effects of a simulated motion environment upon the physical demands of heavy materials handling operators /". 2005.
Cerca il testo completo
44
Lehmann, Frederick Denis. "Weight load carry : a review of the efficiency and effectiveness of the army backpack". Thesis, 2000. http://handle.uws.edu.au:8081/1959.7/663.
Testo completoAbstract (sommario):
Military load carrying has occupied the attention of military developers, researchers and commanders over centuries. The Army backpack remains the means of carriage for ammunition and rations for the soldier in the field. The traditional rationale for its use has been that the infantry soldier must be able to sustain himself in combat and live independently for days at a time without resupply. At the Royal Military College, Duntroon (RMC), the mission is to produce men and women who are capable and effective officers and soldiers. The weight of the pack with the items required at RMC is often in excess of 40 kg. In evaluating the effectiveness of current practice, this thesis takes an anthropometric perspective in exploring the historical, physiological and social context of current loads carried by Australian soldiers, It does not, however, evaluate the content of the load itself. Research methods include: a/. Systematic examination of past research findings on the social and physiological aspects of military load carrying since the Roman Centurions. b/. Biophysical tesing of nine soldiers, using a battery of physiological tests to determine heart rates and energy expenditure at various loads. c/. A survey of 100 soldiers from the Royal Military College, Duntroon and in-depth interviews with a sample of four experienced soldiers to obtain the views of the load carriers. The research concludes that the optimum approach to load carrying, and so to the design of the Army backpack, is that it be task-and soldier-specific. This runs directly counter to the longstanding Army traditions of preparing all soldiers for every possible contingency in battle and regarding all soldiers as equivalent units. The study findings offer some specific directions in which the design of the army backpack can be improved.
45
"biomechanics study of school-bag carrying during stair ascent and descent by children =: 背負書包上落樓梯對學童生物力學反應的硏究". 2002. http://library.cuhk.edu.hk/record=b5891215.
Testo completoAbstract (sommario):
Lau Tsz Chung.Thesis (M.Phil.)--Chinese University of Hong Kong, 2002.
Includes bibliographical references (leaves 57-66).
Text in English; abstracts in English and Chinese.
Lau Tsz Chung.
Acknowledgement --- p.i
Abstract --- p.ii
Table of contents --- p.v
List of Figures --- p.viii
List of Tables --- p.x
Introduction --- p.1
Background --- p.1
Statement of Problem --- p.3
Research Question --- p.4
Significance of the Study --- p.4
Theoretical Contribution --- p.4
Practical Contribution --- p.5
Review of Literature --- p.7
Load carrying on Level Ground --- p.7
Research Method Involved --- p.8
Modified Gait Pattern During Load Carriage --- p.9
Trunk Posture --- p.10
Low Back Pain --- p.11
Posture and Back Pain --- p.12
Load Carrying Studies in Children --- p.14
Stair Walking --- p.15
Compared with Level Walking --- p.15
Temporal Characteristics --- p.17
Kinematics Measurement --- p.18
Stair Dimensions --- p.19
Stair Walking with Load Carriage --- p.21
Physiological Studies --- p.21
Biomechanical Studies --- p.21
Methodology --- p.24
Design --- p.24
Subject --- p.24
Instrumentation --- p.25
Motion Analysis System --- p.25
School Bag --- p.25
Experimental Set-up --- p.25
Procedure --- p.26
Term Definition --- p.27
Data Analysis --- p.27
Results --- p.29
Ascending Stair --- p.29
Posture --- p.29
Effect on Load Weight --- p.29
Effect on Load Carrying Method --- p.30
Velocity --- p.30
Parameters of Lower Extremities --- p.30
Descending Stair --- p.31
Posture --- p.31
Effect on Load Weight --- p.31
Effect on Load Carrying Method --- p.31
Velocity --- p.32
Parameters of Lower Extremities --- p.32
Trend --- p.32
Summary --- p.33
Discussion --- p.35
Ascending Stair --- p.35
Posture --- p.35
Different Load Weights --- p.35
Different Carrying Methods --- p.39
Velocity --- p.40
Descending Stair --- p.42
Posture --- p.42
Velocity --- p.46
Parameters of Lower Extremities --- p.47
Trend --- p.48
Back Pain --- p.49
Recommended Carrying Load Method and Weight for Children --- p.50
Limitations of the Study --- p.52
Further Study --- p.53
Conclusion --- p.56
References --- p.57
Appendix --- p.67
Appendix A - The experimental Set-up --- p.67
Appendix B - Subject Consent Form --- p.68
Appendix C - Figures and Tables --- p.71
46
Mackie, Hamish William. "Schoolbag carriage : design, adjustment, carriage duration and weight : a thesis presented in fulfilment of the requirements for the degree of Doctor of Philosophy in Ergonomics at Massey University, Palmerston North, New Zealand". 2006. http://hdl.handle.net/10179/1478.
Testo completoAbstract (sommario):
There is anecdotal and scientific evidence to suggest that schoolbag carriage is associated with musculoskeletal discomfort (MSD) and possibly long-term back pain. Thus schoolbag carriage is an area of concern for students, parents and both education and health professionals. A schoolbag weight limit of 10% of body weight (BW) is currently recommended. However, it is based on subjective observations rather than objective findings and does not consider other aspects of schoolbag carriage such as schoolbag design and adjustment or carriage patterns. Five studies were conducted in order to determine the effects on students' responses to schoolbag carriage of schoolbag design, adjustment, carriage duration and weight. Backpack design had a significant effect on reported musculoskeletal discomfort and choice of backpack. Schoolbag hip-belt and shoulder strap adjustment and weight significantly affected shoulder strap tension forces and shoulder interface pressure in simulated schoolbag carriage. Using activity monitoring, school students were found to spend approximately two hours carrying their schoolbags each day. This usually comprised 11-15 times per day of 8-9 minutes of carriage. Using this temporal pattern information, 16 boys (13-14 years) were exposed to a simulated school day using schoolbags weighing 0, 5, 10, 12.5 and 15% BW and an additional condition of 10% BW with tighter shoulder straps. Posture, rating of perceived exertion (RPE), muscular strain and reported ability to walk and balance were significantly affected when schoolbag load reached 10% BW. However, despite these findings, the magnitude of self reported muscular strain and MSD suggested that 15% BW may be too heavy for school students. Thus, 10% BW may be an appropriate upper schoolbag weight limit for a typical school day. Using a psychophysical approach the mean (standard deviation) maximum acceptable schoolbag weight (MASW) selected by 16 school boys (13-14 years) was 10.4(3.8) %BW. This finding agrees with the findings of the previous study and supports the current schoolbag weight recommendation of 10% BW. The results of the five studies can be used in developing schoolbag carrying guidelines to help reduce the prevalence of MSD amongst school students.