The biomechanical determinants of sports related groin pain in athletes.

Abstract

Introduction Sports related groin pain (SRGP) is common, debilitating and often recurrent. Rehabilitation that addresses strength and flexibility deficits has only moderate effects. Recurrence of SRGP remains high, suggesting that deficits remain after apparently successful rehabilitation. The aims of this thesis were to inform best practice by (i) systematically reviewing the literature on biomechanical factors associated with SRGP (ii) investigating muscle activation and movement patterns associated with SRGP in both professional and amateur athletes; (iii) investigating muscle activation and movement patterns immediately after groin injury alongside their response to standard rehabilitation. Methods A systematic review with meta-analysis was completed. 84 athletes from four sports (56 professional and 28 amateur) were recruited and clinically assessed. Hip joint kinematics and surface electromyography of gluteus medius (GM) and adductor longus (AL) muscles were measured while performing selected manoeuvres. A further 5 athletes had serial measures during traditional rehabilitation from acute injury. Results The review found strong evidence for decreased adductor flexibility as a risk factor; and decreased adductor strength and external rotation range of movement being associated with SRGP. The GM:AL ratio in injured professionals was increased due to reduced AL activation, a decreased GM:AL ratio was found in amateurs due to a decrease of GM activation. In injured professionals hip kinematic change matched the sEMG findings (increased abduction), whereas no consistent pattern was observed in amateurs. Longitudinal study participants 7 improved clinically after groin injury, but the muscle activation and movement patterns did not alter. Conclusion These studies identified clear muscle activation differences that extend existing the literature while the kinematic changes are novel. Further, participation level and sports-specific subgroups had not previously been identified but are clearly evident. Published guidelines require amendment, while clinical innovation that addresses sub-group specific biomechanical factors in rehabilitation programmes may inform prevention, improve outcome and certainly warrant further research.