Musculoskeletal screening to detect asymmetry in swimming

ObjectivesTo investigate the influence of asymmetry of clinical strength musculoskeletal screening measures and 3D kinematic movements on bilateral hand-force performance measures in swimmers.DesignCross-sectional.SettingInstitutional.Participants32 national-ranked junior swimmers, 100 m freestyle time (mean (SD), 60.68 s (4.81)).Main outcome measurementsScreened clinical strength, kinematic movements, and bilateral hand-force were measured. Asymmetry was defined as a percentage difference greater than 10 percent, either left (negative) or right (positive) for all variables.ResultsAsymmetry of the clinical strength measures was found in ∼85% of swimmers. Athletes with symmetry of all clinical strength measures displayed symmetrical bilateral hand force production. Approximately 50% of clinically asymmetrical swimmers were able to compensate, due to summated muscle symmetry and/or an altered kinematic movement pattern, and generate symmetrical hand force.ConclusionsSymmetry of clinical strength was directly related to symmetrical force output. It is important to connect the clinical screening results to the sport-specific performance measures to ensure functional and valid screening is undertaken. Clinicians should aim for symmetry of strength in order to minimise the requirement for compensatory strategies.