Impact of Carry Angle Variation on Shoulder Joint Stability and Risk of Shoulder Injury in Fast Bowlers

Abstract

Background: Fast bowling involves repetitive high-velocity arm motions that place significant biomechanical stress on the shoulder. Shoulder injuries in fast bowlers often result from instability, overuse, and poor kinetic mechanics. The carry angle between the humerus and ulna affects upper limb alignment, and abnormal variations may disrupt force transmission, compromising shoulder stability and increasing injury risk. Objective: To determine the impact of carry angle variation on shoulder joint stability and the risk of shoulder injury among fast bowlers. Methodology: A cross-sectional analytical study was conducted at Peshawar Sports Complex on 80 male fast bowlers aged 18 to 30 years with at least two years of competitive experience. The carry angle was measured using a goniometer, and shoulder stability was evaluated through the Oxford Shoulder Instability Score and clinical tests. Shoulder injuries were recorded using the OSICS-10 questionnaire. Data were analyzed in SPSS 25 using Pearson’s correlation, independent t-test, and logistic regression, with p ≤ 0.05 considered significant. Intra-rater reliability was established through pilot testing on ten participants, yielding an intraclass correlation coefficient (ICC) of 0.91, confirming the reliability of both goniometric and questionnaire-based assessments. Results: The mean dominant-arm carrying angle was 11.2±2.1°, significantly higher than the non-dominant arm (8.6±1.8°, p<0.00). A negative correlation existed between carrying angle and shoulder stability (r=−0.52, p<0.01), while a positive correlation was found between carrying angle and shoulder injury occurrence (r=0.47, p<0.01). Bowlers with a carrying angle greater than 12° had significantly reduced stability scores (32.4±5.6) and higher injury rates (58.6%) than those with normal angles (40.8±4.9, 31.4%, p=0.01). Logistic regression revealed that each 1° increase in carrying angle predicted a 0.43-point decrease in shoulder stability (β=−0.43, p=0.00) and a 12% higher injury risk (OR=1.12, 95% CI: 1.04–1.24, p=0.00). Conclusion: An increased carrying angle significantly reduced shoulder joint stability and increased the risk of shoulder injury among fast bowlers. Routine biomechanical screening and corrective training should be incorporated in cricket conditioning programs to minimize shoulder injuries linked with excessive carrying angles.