Rozprawy doktorskie na temat „Cricket injuries”

Fast bowlers are especially prone to injury as they perform their bowling techniques repetitively at very high intensities. The fast bowling action in the past has been described as a highly explosive activity that produces high levels of stress and strain on the body. The aim of this study was to compile an injury profile of 46 fast bowlers aged 11 to 18, and to identify the associated risk factors for injury during an academy cricket season. A descriptive correlational research design was utilised. Subjects were selected according to age and fast bowling ability. These subjects were observed for one academy cricket season (March to November). Three testing sessions occurred during this time (T1, T2 and T3). Each subject completed two questionnaires: i) bowler history (at T1) and ii) injury history (at T1, T2, and T3). These assisted in grouping the subjects according to their responses into one of three injury classifications (uninjured = S1; injured but able to play = S2; injured and unable to play = S3). Anthropometric and postural data for the entire group of fast bowlers were also collected pre-season (T1). Physical fitness screenings were also conducted during each of the three testing sessions to establish any relationship between the fitness of each fast bowler and the occurrence of injuries. Additional factors assessed during the season were bowling techniques and bowling workload. Statistical significance was indicated by p-values less than .05 (p< .05), while practical significance was indicated by either Cohen’s d-values of 0.2 or better (d>0.2) for tests based on sample means or Cramer’s V for tests based on sample frequencies, the values of which depend on the applicable degrees of freedom. All fitness scores as well as bowling workload figures for each testing session were converted to standard T-scores and these in turn were summated to derive overall fitness and workload T-scores. ‘TT’ indicated the overall average score for the entire season. Changes in performances, bowling workload and injury status were analysed using ANOVA and ANCOVA. A regression analysis was also conducted to analyse the relationship between bowling workload and weeks incapacitated. This study found that hyperextension in the knees had the highest incidence of postural deviation injury (43 percent) followed by winged scapula (39 percent). Only 15 percent of the fast bowlers remained injury-free for the duration of the season, while 35 percent of the subjects were at some stage injured to such an extent that they were unable to play. The incidence of serious injury (S3) showed a statistical and moderate practical (V=0.23, d.f. ≥2) significant increase throughout the data collection period (4 percent at T1 to 30 percent at T3). The most common injury was to the knee (41 percent) followed by those to the lower back (37 percent). These injuries occurred mostly during test periods T2 and T3. The nature of injuries were predominantly strains and "other" which accounted for 39 percent of the injuries overall (TT) and had the highest reported incidence during the period T1 to T3. Sprains followed with an overall incidence of 14 percent. Less frequently reported injuries were tears, fractures, bruises and dislocations. The degree of severity of injuries was defined in terms of the number of weeks a player reported being incapacitated as a result of injury during the academy session. During midand end-season bowlers were on average incapacitated approximately one week out of every five due to injury. The statistics for the duration of the study translate to approximately one week incapacitated out of every seven weeks of play. When comparing the S1/S2 bowlers with the S3 group, the S1/S2 bowlers performed consistently better than the S3 bowlers in all the fitness variables tested. However no significant differences (p>.05) in either flexibility or muscle strength were observed. Of the risk factors analysed, bowling workload presented a statistically significant (p<.0005) increased risk for injury. A strong significant positive relationship (p<.0005, R²=.619) was found between weeks incapacitated and bowling workload, supporting the finding that increased bowling workloads show a linear relationship with the increase in the number of weeks incapacitated from normal play. This study concluded that inadequate fitness, high bowling workload and bowling technique all have a multi-factorial role in predisposing a bowler to increased risk for injury. These variables did not act alone, but have all contributed to recurring injuries. The bowling action alone would not have been detrimental if the workloads were not in excess of the recommended guidelines. Furthermore the workload would not have been as detrimental if the bowlers were well conditioned and uninjured. Management of minor injuries and adequate recovery time, coupled with adequate and relevant fitness preparation would better prepare fast bowlers for the demands of the game.

Cricket is one of Australia's most popular sports, both in terms of participation rates and spectator interest. However, as with all sports, participation in cricket can be associated with a risk of injury. Injury surveillance in Australia and internationally has consistently identified fast bowlers as the players at the greatest risk of injury. This clearly establishes fast bowlers as the priority group for continued risk factor research. The primary aim of this thesis is to describe the epidemiology of repetitive microtrauma injuries and identify the risk factors for these injuries to male adolescent and adult fast bowlers. The program of research consists of three sequential prospective cohort studies, which were conducted over four cricket seasons. The rate of injury was high in all these studies, with nearly half of the 305 bowlers sustaining an injury. The first of the three studies, which was conducted over three seasons, recruited 95 adult first-class fast bowlers and investigated bowling workload as a risk factor for injury. The findings suggested that there were thresholds for both low and high workload, beyond which the risk of injury increased. The second study recruited 47 adolescent high performance fast bowlers for one season, and identified a significant association between high bowling workload and injury. Based on the results of these two studies, workload guidelines for adult and adolescent fast bowlers are described in detail in this thesis. The third study expanded on the first two workload studies and concurrently investigated a range of potential injury risk factors relating to bowling workload, physical characteristics and bowling technique. A total of 91 adult and adolescent high performance fast bowlers participated in the third study for one season. Two independent predictors of injury were identified: increased hip internal rotation and reduced ankle dorsiflexion. This program of research has provided information that is essential for the development of evidence-based injury prevention guidelines for adolescent and adult fast bowlers. The next stage in the injury prevention process is to implement measures that control the exposure to the injury risk factors identified in this thesis.

Injury surveillance research has established that over 20 % of cricket injuries are related to the upper limb (Leary & White, 2000; Ranson & Gregory, 2008; Stretch, 2003), with bowlers associated altered rotational joint range of motion (Aginsky et al., 2004, BellJenje & Gray, 2005 and Stuelcken et al., 2008). As the applicability of such observations is limited, the aim of this thesis was to provide researchers with a greater understanding of the pathomechanics of shoulder injuries afflicting cricket bowlers though quantifying associated musculoskeletal adaptations and subsequently through the development and validation of a bowling specific kinematic model, establish the influence these may impart on bowling technique. The use of diagnostic ultrasound within the first experimental study in a cohort of bowlers without a history of shoulder injury, established a high prevalence of supraspinatus (45 %) and subscapularis (50 %) tendon pathology, providing insight into common musculotendinous pathology and adaptations that are indicative of the future potential of injury. Data presented within the second study aimed to first quantify the kinematics of the shoulder during the bowling delivery in relation to humerothoracic motion and, second, the influence of rotation sequence to described humerothoracic motion was investigated. Findings established that whilst the bowling delivery was associated with large variability, future research must acknowledge the contribution of the scapula to shoulder motion. As such, due to the complexity of quantifying shoulder motion during cricket bowling, the following three experimental studies evaluated and developed the CSBT shoulder model through modifying current methods. The mCAST method in conjunction with an acromion cluster, was established to not only reduce resultant RMSE associated with scapula landmarks by up to 0.016 m, but also increase the repeatability and robustness of reconstructing GHJ location using the SCoRE method. The emphasis of the final experimental study was to apply the CSBT shoulder model to establish the contribution of individual rotator cuff muscles to shoulder joint stability and, to identify phases of the bowling delivery which increases the risk of injury. This case study established that during the bowling delivery the shoulder experiences large multi-planar forces placing demand on musculature, in particular supraspinatus and Subscapularis to stabilise the joint. These findings in conjunction with those of the first experimental study, not only identify structures at risk of injury but also establish that for the effective formulation of injury prevention strategies the bowling delivery must be investigated in its entirety.

Background: Literature has associated repeated eccentric muscle actions with increased muscle damage of the muscles involved. Eccentric actions are typical in sports which are ‘stop-start’ in nature requiring rapid acceleration and deceleration, typical of a batting activity in cricket. Ultra-structural damage of the skeletal muscle as a consequence of repeated decelerating activities is associated with performance decrements, particularly muscle strength and sprinting speeds. This suggests that eccentric strength decrements may provide an indication for the development of muscle strain injuries during these activities. Despite these findings, limited research has identified the specific musculoskeletal demands placed on cricket batsmen, particularly with reference to various match intensities. Objective: The present study, therefore, sought to determine the specific musculoskeletal, physiological and perceptual demands placed on specialised batsmen during two work bouts of different intensities; one representing a highintensity work bout and the other a moderate-intensity work bout. The dependent variables of interest were muscle activation, isokinetic strength changes, heart rate, ‘central’ and ‘local’ ratings of perceived exertion (RPE), body discomfort and performance. Methods: The two experimental conditions, representative of a high- (HVR) and moderate-volume running (MVR) batting protocol, required players to perform a simulated batting work bout of either twelve or six runs an over, within a laboratory setting. Selected physiological, perceptual and performance measures were collected at specific time intervals throughout the work bout while the biophysical measures were collected prior to, and following both protocols. Results: Of the variables measured, heart rate, ‘central’ and ‘local’ RPE values were observed to increase significantly (p<0.05) over time. This increase was greater as a consequence of the HVR in comparison to the MVR. No change in sprint times was documented during the MVR, in contrast, significant (p<0.05) increases over time were observed during the HVR, further highlighting the elevated demands associated with this condition. In addition, an ‘end spurt’ was observed particularly following the HVR condition, suggesting athletes were conserving themselves through the adoption of a pacing strategy. Reductions in biceps femoris and semitendinosus muscle activation levels were observed following the HVR. This was further supported by the significantly greater levels of semitendinosus activation following the MVR when compared to the HVR. Peak concentric and eccentric knee extensor (EXT) (-17.17% and -16.07% respectively) and eccentric flexor (FLEX) (- 17.49%) values decreased significantly (p<0.05) following the HVR at 60°.s-1. In addition, concentric and eccentric total work produced by the flexors and eccentric extensors resulted in significantly (p<0.05) lower values due to the HVR. Conclusion: The intermittent high-volume batting work bout elicited elevated mean heart rates, perceived ratings of cardiovascular and muscular effort and sprint times. Furthermore, hamstring activation levels and muscle strength, particularly concentric strength of the dominant lower limb were negatively affected by the HVR condition. These results suggest elevated demands were placed on the hamstring musculature as a consequence of the HVR condition, indicating a greater degree of musculoskeletal strain and increased injury risk associated with running between the wickets at this intensity, representative of an aggressive batting scenario.

This study investigates the effects of cumulative concussive and subconcussive mild head injury on the cognitive functioning of professional rugby players. A comprehensive battery of neuropsychological tests was administered to 26 professional rugby players and a noncontact sport control group of 21 professional cricket players. The test performances of the rugby players were compared to those of the cricket players. Within the rugby group, forward and backline players were compared. An analysis of mean score differences between the rugby and cricket group failed to support the presence of brain damage effects in the rugby group. However, there was significantly increased variability of scores for the rugby players compared with the cricket players on tests particularly sensitive to cognitive deficit associated with mild head injury. This invalidates the null indications of average effects, indicating that a notable proportion of rugby players’ performances were falling off relative to the rest of the rugby players on tests vulnerable to the cognitive effects of diffuse brain damage. Mean score comparisons within the rugby group indicated that it was the subgroup of forward players, in particular, whose test performances revealed deficits suggestive of cerebral damage. Specifically, deficits were found in working memory, visuoperceptual tracking, verbal memory and visual memory, a pattern of deficits commensurate with cumulative mild head injury. The theoretical perspectives of Satz’s (1997) Brain Reserve Capacity Theory and Jordan’s (1997) ‘Shuttle’ model of variability are drawn upon in order to elucidate research findings and suggestions for future research are provided.

Background: The musculoskeletal demands placed on the lower limb musculature of fast bowlers over time have not received much attention. In particular, measures of muscle recruitment changes have, to the author’s knowledge, not been considered. Objective: The present study, therefore sought to establish any associations between an eight over, simulated fast bowling spell, and muscle activation patterns, power output, perceptual demands, and changes in performance. This will enable improvements in the development of training programmes. Methods: Players’ were required to attend two sessions in total. The purpose of the initial session was to collect specific demographic, anthropometric and physiological data and injury history information from each player. In addition, this first session allowed for habituation with the treadmill, the jump meter and all other equipment involved in experimentation. The second testing session involved electrode attachment sites being identified on player’s dominant leg. The areas were then shaved, wiped with an alcohol swab and left to dry, to ensure good connectivity. Pre- and post- measures of muscle activity and functional strength of the lower limbs were recorded in the Department of Human Kinetics and Ergonomics. The protocol took place at the Kingswood High Performance Centre, which is in close proximity to the initial testing site. The protocol involved players bowling eight overs (48 balls). During the protocol, accuracy, ball release speed and perceptual measures were recorded at the end of each over. After the protocol, players were driven back to the Human Kinetics and Ergonomics Department where post-testing measures were completed. The dependable variables of interest were muscle activation, functional strength of the lower limbs, ‘local’ ratings of perceived exertion (RPE), body discomfort, accuracy, and ball release speed. Results: For all muscles it was shown that, as the speed increased so did the muscle activity in players’ lower limbs. There were no significant changes in muscle activity preversus post-protocol. There was however, a general trend of decreasing muscle activity post protocol at higher testing speeds. There were significant (p<0.05) decreases in peak power following the simulated eight over bowling spell. ‘Local’ RPE displayed a significant (P<0.05) increase with each additional over and were observed to reach the ‘heavy’ category. The players’ highest discomfort area was in the lower back, with 13 players perceiving discomfort in this region following the eight over spell. The shoulder and chest were another two areas player’s indicated discomfort with eight players selecting the dominant shoulder. Seven players complained of the dominant side pectoral muscle, leading foot and dominant latissimus dorsi muscle being uncomfortable. Interestingly, the dominant pectoral showed the highest body discomfort ratings amongst players. There were no significant changes in accuracy between overs although there were large interindividual differences in accuracy points between players. The decrease in ball release speed observed during over seven was shown to be significantly (p<0.05) lower than overs one to four. Conclusion: The power output and perceived strain results of the players, appears to indicate the presence of fatigue in players. However, the results are not conclusive, as the fatigue was not shown in muscle recruitment patterns, as well as the body discomfort ratings. There was a non-significant trend observed in the lower limb muscle activation decreasing at higher speeds. Players were able to maintain accuracy. However, the significantly lower ball release speed observed during over seven showed players performance decreasing.

Thesis (MScPhysio)--University of Stellenbosch, 2011.
ENGLISH ABSTRACT: Aim: The aim of the study was to improve understanding of the hip joint kinematics in cricket fast bowlers and to ascertain whether a relationship exists between hip joint biomechanical parameters, including kinematics, ROM characteristics and lumbar symptoms. Study design: A descriptive cross-sectional study was conducted. Participants: Sixteen adult male fast bowlers between the ages of 18 and 40 years old, playing first-club league, were featured in the study. Main outcome measures: To obtain data with regards to the training history, as well as the nature of lumbar-spine symptoms experienced by the cricket fast bowlers, a newly designed questionnaire was compiled. For analysis of the front foot hip joint ROM and kinematics, the biomechanical equipment used included: a two-dimensional Canon MV950 Digital Video Camcorder, a Kodak EasyShare C310 camera and XSENS Motion Tracking equipment (Xsens Technologies B. V., Enschede, Netherlands). Results: Eight of the sixteen bowlers in our study experienced LBP in the season with seven of these bowlers presenting with recent symptoms most of which are experienced after bowling a spell and described as “tightness” or a “stabbing pain” in the lower back. Intensity of LBP ranged between 1/10 to 8/10. Front foot hip joint kinematics of fast bowlers showed highly individualised patterns of movement between different subjects. Medium amplitude movements in the flexion/extension as well as the rotation plane of movement showed a significant difference in bowlers with- and without LBP. No significant differences between groups with LBP and without LBP were found in the three passive hip ROM measurements. Conclusions: It has proved to be very difficult to improve the understanding of the front foot hip biomechanics in cricket fast bowlers due to the high inter-subject variability. Variability in movement patterns remains under-researched by sports biomechanics. Although decreased hip mobility could alter mechanical forces transmitted to the lumbar spine and therefore predispose or be a causative factor in LBP development, this study found no significant relation between these parameters. The sample size was very small in this study which will influence the validity of results. Our study confirmed the high incidence of LBP and preventative efforts for bowlers should therefore be strongly supported.
AFRIKAANSE OPSOMMING: Doelwit: Die doelwit van die studie was om die heupgewrig kinematika van krieket snelboulers beter te verstaan en om vas te stel of daar ‘n verwantskap bestaan tussen heupgewrig biomeganiese parameters, insluitende kinematika, omvang van beweging karakter en lumbale simptome. Studie ontwerp: ‘n Deursneë beskrywende studie is onderneem. Deelnemers: Sestien volwasse manlike snelboulers tussen die ouderdomme van 18 en 40 jaar oud wat eerste liga speel maak deel uit van die studie. Hoof uitkoms maatreëls: ‘n Nuut ontwerpte vraelys is opgestel om data aangaande oefen geskiedenis sowel as aard van lumbale simptome wat deur krieket snelboulers ervaar word in te samel. Die biomeganiese apparaat wat gebruik is vir die analiese van die voorvoet heup omvang van beweging, sowel as die kinematika, sluit in: ‘n twee dimensionele Canon MV950 Digitale Video Camcorder, ‘n Kodak EasyShare C310 kamera en XSENS beweging volgende apparaat (Xsens Technologies B. V., Enschede, Netherlands). Resultate: Agt van die sestien boulers in ons studie het lae rug pyn in die seisoen ervaar. Sewe van die boulers het gepresenteer met onlangse simptome waarvan die meeste na ‘n bouler se boulbeurt ervaar is en beskryf was as ‘n “styfheid” of “steekpyn” in die lae rug. Die intensiteit van die lae rug pyn het gewissel tussen 1/10 en 8/10. Voorvoet heup kinematika van snelboulers het hoogs individualistiese patrone van beweging getoon tussen verskillende deelnemers. Medium amplitude bewegings in die fleksie/ekstensie sowel as die rotasie plein van beweging het ‘n beduidende verskil tussen boulers met- en sonder lae rug pyn getoon. Geen beduidende verskille tussen die groep met- en sonder rugpyn is gevind met die drie passiewe heup omvang van beweging meetings nie. Gevolgtrekkings: Dit blyk baie moelik te wees om die voorvoet heup biomeganika in krieket snelboulers beter te verstaan a.g.v. die hoë inter-deelnemer veranderlikheid. Veranderlikheid in bewegings patrone is nog nie genoeg nagevors deur sport biomeganici nie. Alhoewel ingekorte heup mobiliteit meganiese kragte wat deur die lumbale werwelkolom gaan kan wysig, en sodoende die ontwikkeling van lae rug pyn kan predisponeer of ‘n oorsakende faktor kan wees, het hierdie studie nie ‘n beduidende verwantskap tussen die parameters gevind nie. Die steekproef groote was baie klein en dit sal die geldigheid van die resultate beïnvloed. Ons studie het die hoë insidensie van lae rug pyn bevestig en pogings tot voorkomende maatreëls moet daarom ten sterkste ondersteun word.

The aim of this study was to investigate the effect of cumulative mild head injury on the cognitive functioning of professional rugby players. A comprehensive battery of neuropsychological tests was administered to 26 professional rugby players and to a comparison group of 21 professional cricket players. The group test results of the rugby, cricket, rugby forwards and rugby backline players were each compared with established normative data. Generally, the comparison of the rugby and cricket mean scores relative to the normative data did not reveal significant differences on tests known to be sensitive to the effects of mild head injury. However, the comparison of variability for each of the rugby and cricket playing groups relative to variability for the normative data, revealed a pattern of increased variability among the rugby players. This implies a bimodal distribution in which a significant number of rugby players were performing poorly across these tests whereas a significant proportion were not. This variability effect was accounted for by further mean score comparisons which revealed that, as a group, it was the forward players whose performances were disproportionately poor on tests sensitive to the effects of mild head injury. The implications of these results are developed theoretically within the context of brain reserve capacity theory and suggestions for future research are provided.

Dissertation submitted in partial compliance with the requirements for the Master's Degree in Technology: Chiropractic, Durban University of Technology, 2009.
Objective: Literature has focused its efforts on professional cricket players and player related risk factors to injury with little information being available with regards to coaching / management and environmental risk factors to injury. Therefore, this study aimed to profile the injuries and risk factors in Premier League club cricketers in the greater Durban area. Methods: This was a prospective, cross-sectional based study, using a self-administered questionnaire, developed specifically for this research utilizing a focus group and pilot study. The questionnaire consisted of a demographics section, as well as an injury history and risk factor section. Letters of informed consent and questionnaire were distributed to 144 players / coaches for completion. Data was analysed using Pearson‟s correlation and t-tests. Results: A response rate of 70% (n=109) was achieved. Selected parameters from demographics, injury history and risk factors were found to be significantly related to current and / or previous injury. Conclusion: It is advised that coaches heed significant injury parameters in order to improve player health, decrease injury risk and decrease time out of play. Key words: Athletic injuries; questionnaires; cross-sectional study‟s; risk factors; sports; sports medicine; risk assessment; cricket.

Dissertation submitted in partial compliance with the requirements for the Master’s Degree in Technology: Chiropractic at the Durban Institute of Technology, 2008.
Purpose Cricket fast bowlers are prone to the development of Myofascial pain syndrome and in particular active myofascial trigger points in their rotator cuff muscles of the shoulder joint (Scott, et al. 2001). This is due to the severe stresses placed upon the muscles, bones and joints of the shoulder as a result of the high velocity throwing action (Bartlett, et al.1996). In muscles containing active myofascial trigger points a decrease in the stretch range of motion as well as the maximal contractile force is noted, these two factors may negatively affect the speed at which a fast bowler deliver the ball (Travell, Simons and Simons, 1999). Dry needling is viewed as the most effective means of deactivating myofascial trigger points leading to in increase in both the contractile force and range of motion of the affected muscle, which could increase the speed at which the bowler delivers the ball (Wilks, 2003). The aim of the study was to determine the immediate effect of dry needling active myofascial trigger points of the rotator cuff on bowling speed in action cricket fast bowlers. Method The study consisted of 40 participants (randomly split into two equal groups of 20) each with shoulder pain of a myofascial origin. Group A (intervention group) received the dry needling intervention in their most tender active myofascial trigger point. While participants in Group B (control group) received no treatment. Bowling speeds were measured both before and after the intervention, to determine its effect on bowling speed. IV Data was entered into MS Exel spreadsheet and imported into SPSS version 15 (SPSS Inc.,Chicago, Iiiinois, USA), which was used for data analysis. Paticipants were evaluated on bowling speed, Algometer readings and Numerical pain rating Scale (NRS) both pre and post intervention. Participants were also asked if they believed the intervention increased, decreased or had no effect on their bowling speeds. Two sample t-test was used to compare baseline values between the groups. A repeated measure ANOVA was used to compare the rate of change of each outcome over time in the two groups. Pearson’s correlation analysis (intra-group) was used to assess the strength and magnitude of correlations of the changes in the outcomes. The McNemar – Bowker test and Weighted Cohen’s kappa statistics were calculated to assess agreement between perceived and actual levels of change. Results A significant treatment effect was observed in the intervention group were an increase in bowling speed, algometer readings as well a decrease in Numerical pain rating scale(NRS) scores was observed. There was also a perceived increase in the speed the participants delivered the ball in the intervention group. No significant changes were observed in the control group. The findings of this study indicate that dry needling as a treatment modality would be beneficial to fast bowlers in not only increasing their speeds but also the pain experienced as a result of active myofascial trigger points.

A dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Physiotherapy Johannesburg, 2017
This research makes a meaningful contribution to the development of effective injury prevention strategies among adolescent cricket pace bowlers. This dissertation, specifically investigated two screening procedures, the Functional Movement Screen (FMS) and ultrasound measured abdominal wall muscle thickness, both of which aim to predict injury among the general and sporting population. More specifically, the dissertation investigated the applicability of these screening procedures to adolescent cricket pace bowlers. Adolescent pace bowlers are prone to injury due to the high load and complex nature of the bowling action as well the risk factors associated with the adolescent growth spurt. Studies related to the validity of the FMS in terms of the prediction of injuries among various sporting disciplines have been conducted but none among cricket pace bowlers. Studies related to the association between abdominal wall muscle morphometry (i.e. thickness at rest and during the performance of abdominal drawing in manoeuvre (ADIM), as measured by ultrasound imaging (USI), and injury among professional and amateur cricket pace bowlers have had conflicting results and limited research related to abdominal muscle morphometry among the adolescent pace bowlers exist. Adolescent pace bowlers that were injury free at the start of the season were recruited for this study. Details related to the nature of past injuries as well as injuries sustained during the season were monitored and recorded over a three month period. Included in this dissertation are three original papers. The first two investigated the association between prospective in-season injury and the two above mentioned screening procedures. The third investigated the concurrent validity of FMS overhead deep squat (DS) when observer rating was compared to kinematic analysis. The first paper (Chapter 4) investigated the association between muscle morphometry of transverse abdominis (TA), internal oblique (IO) and external oblique (EO), as measured by USI, at the start of the season and in-season injury. Results indicated that non-dominant internal oblique is thicker than dominant IO (p=0.01, effect size (ES) =0.65) in injury free pace bowlers but that non-dominant and dominant internal oblique (p=0.47; ES=0.24) is symmetrical in injured pace bowlers. Based on these findings we concluded that asymmetry in IO thickness may play a protective role against injury rather than being a predisposing risk factor to injury. The second paper (Chapter 5) investigated the association between pre-season total FMS score and in-season injury among adolescent pace bowlers. Results indicated that there was no significant difference in total pre-season FMS scores of bowlers that sustained injuries during the season and those that remained injury free (p=0.58). Also, a total FMS score of 14 (the score previously found to be an accurate cut-off score) does not provide the sensitivity needed to assess injury risk among adolescent pace bowlers. It was therefore concluded that the FMS was not associated with in-season injury among adolescent pace bowlers and that the usefulness of this tool in the prediction of injuries among these cricketers is doubtful Paper 3 (Chapter 7) investigated the concurrent validity of the overhead DS included in the FMS when observer rating is compared to kinematic analyses. The FMS attempts to systematically score the quality of movements, among other the DS, based on specific criteria. The developers of the FMS suggest that specific mechanics related to the DS differ between levels of scoring. There were significant differences in the degree to which the torso was flexed forward, away from the vertical (p=0.03), where groups 3 and 2 (i.e. those participants who scored a rating of 3 and 2 respectively for the performance of the DS) remained more upright compared to Group 1. There was also a significant difference in the degree to which the femur passed the horizontal line (p=0.05) between the three groups. At the point of deepest descent, the femurs of Groups 3 and 2 were below the horizontal while that of Group 1 remained above. The findings of this part of the study suggest that, while raters correctly identified differences in biomechanics between groups for two of the scoring criteria (femur below horizontal and feet remaining flat on floor or board) , they did not rate the groups correctly for the remaining criteria. The concurrent validity of the observer rating of the FMS DS is therefore questionable. In conclusion, the high load nature and complexity of the pace bowling action together with the intrinsic risk factors related to the adolescent growth spurt, expose school boy cricket pace bowlers to injury. The ability of these screening procedures to accurately identify individuals at risk of sustaining injuries are therefore of the utmost importance. Despite the popularity of the FMS, the concurrent validity of this screening tool and its lack of association with in- season injury among adolescent pace bowlers brings the use of FMS into question. Symmetry, not asymmetry, of the IO and under-, not over-activation of the dominant TA muscles were associated with in-season injuries among pace bowlers. All of the above conflicting findings pose uncertainty regarding the applicability of these screening procedures to injury prediction among adolescent cricket pace bowlers.
MT2017