This research report is presented to the University of the Witwatersrand in partial fulfilment of the requirements for the degree of Master of Science in Physiotherapy Johannesburg, 2017 / BACKGROUND: The game of cricket requires the repetitive use of the upper limbs in batting, bowling and fielding. Shoulder injuries are prevalent in cricket players with the most common activities causing injury being fielding and bowling. There is no research on pectoralis minor muscle length in cricketers or the role that the throwing arc range of movement (ROM) plays in shoulder injuries, in a male only cricket population older than 18 years of age. OBJECTIVE: The objective of this study was to determine if there is an association between shoulder rotation ROM, throwing arc ROM, pectoralis minor muscle length, and incidence of shoulder injury, as monitored in the first three months of a cricket season METHOD: This was a prospective, observational cohort study. Thirty six male, provincial and club cricket players, with and without shoulder pain, were recruited. Shoulder internal rotation ROM, external rotation ROM and pectoralis minor muscle length test distance were measured at the beginning of a cricket season and during the first three weeks of the in-season. Glenohumeral internal rotation deficit (GIRD), external rotation gain (ERG) and throwing arc ROM were calculated from these measurements. The incidence of injury was monitored for three months. Comparisons were made between the injured and uninjured groups. Parametric data were analysed using independent t-tests and paired t-tests. Non-parametric data were analysed with the Mann-Whitney U tests, chi-squared tests and Sign tests. A logistic regression model was used to determine the relationship between variables. RESULTS: Thirty six participants were recruited and underwent the baseline testing procedure, although only thirty two participants’ data were analysed. During the study, four participants were not exposed to the typical cricket training and match workloads and were therefore excluded from the study. The mean age of participants was 23.56 (SD ± 4.27) years. Nine participants (28%) sustained dominant shoulder injuries and twenty-three (72%) remained uninjured. The presence of initial shoulder pain at rest, during or after training (p = 0.007) at the beginning of the season occurred in six participants who sustained shoulder injuries during the season. There were no statistically significant differences between the injured and uninjured group in any of the other variables. All pre-season measurements in the entire group were significantly different between the dominant and non-dominant upper limb. The external rotation ROM (p = 0.0037) was increased on the dominant side and the internal rotation ROM (p < 0.0001), throwing arc ROM (p = 0.016) and pectoralis minor muscle length (p = 0.0001) (decreased pectoralis minor length test distance) was increased on the non-dominant side. In the injured group, there was no significant difference between dominant and non-dominant measurements. The uninjured group had a smaller dominant internal rotation ROM (p = 0.0001), throwing arc ROM (p = 0.005) and pectoralis minor muscle length (p = 0.0002) (larger pectoralis minor length test distance) which was statistically significantly different to the non-dominant shoulder. A logistic regression analysis found no association between the variables and injury. CONCLUSION: Shoulder pain at the beginning of the season may be a precursor to shoulder injuries in cricket players. The presence of pain should be questioned during the pre-season screening, so that preventative programmes may be put into place to prevent shoulder injuries which result in time out of play. Asymmetries were found in the uninjured group with internal rotation ROM, throwing arc ROM and pectoralis minor muscle length although, no asymmetries existed in the injured group. These asymmetries may have a protective role in injury prevention whereas, non-asymmetries (as seen in the injured participants) may precipitate dominant shoulder injuries. / MT2017