Evaluation of the effects of tennis on the shoulder biomechanics of master athletes for the identification of injury risk factors

The research project presented in this thesis originates from the collaboration between researchers affiliated with the Department of Human and Health Sciences, the Integrated Laboratory of Exercise Physiology, the Laboratory of Bioengineering and Neuromechanics of Movement at the University of Rome Foro Italico, clinicians from the University Foundation Foro Italico and clinicians from Fondazione Policlinico Universitario Campus Bio Medico. The aim of this PhD thesis is to comprehensively outline the shoulder biomechanics of master tennis athletes, encompassing aspects such as shoulder strength, range of motion, and scapula humeral rhythm. This thesis also aims to pinpoint potential risk factors for injuries and contribute a reference dataset pertaining to master tennis athletes, which has been notably absent from existing literature. Tennis, characterized by repetitive upper limb movements, especially overhead actions, heightens the susceptibility to upper limb injuries. Specifically, the shoulder emerges as a focal point of vulnerability due to the substantial loads and forces it sustains during play. Moreover, this vulnerability appears to exhibit age related and activity dependent correlations. Existing literature predominantly focuses on investigations involving young athletes (aged 10-17) or amateur female tennis players, underscoring the compelling need for research involving adult master athletes (aged over 40). To achieve this goal, it was necessary to identify in the literature the criteria commonly used to determine an athlete's readiness to return to sports after shoulder injury, particularly following rotator cuff surgery, a common occurrence among tennis athletes. Consequently, the first chapter presents the results of a systematic review aimed at establishing these criteria. The second part of this thesis focuses on the assessment of shoulder muscle strength and scapulohumeral rhythm. We present the results of a study published in the Journal of Functional Morphology and Kinesiology, demonstrating how posture and grip modality influence strength assessments, specifically maximum voluntary isometric contraction. This highlights the critical importance of a thoughtful choice when employing these assessments in clinical contexts to determine an athlete's readiness to return to sports following an injury. Additionally, this thesis presents the details of the MATLAB code development process used to compute scapulohumeral rhythm using four magneto-inertial sensors within the assessment protocol. Finally, the concluding part of this thesis reports the results of the biomechanical assessment of the shoulder in a population of master tennis players, comparing them to a cohort of non-tennis athletes of the same age focusing on the identification of biomechanical variations that may serve as indicators of an elevated risk of shoulder injury.