Assessment of upper limb function in swimmers through functional tests and posturography and its relationship with musculoskeletal dysfunctions

Abstract

Introduction: The repetition of movements and high stress on the shoulder joint, common in competitive swimming, can lead to musculoskeletal dysfunctions. Since the assessment of functionality and the risk of dysfunction is an integral part of the rehabilitation process, new clinical-functional tests and measurement tools are frequently developed. Understanding the neuromuscular mechanisms underlying functional performance and their relationship with subsequent dysfunctions in the
shoulder complex are the key themes addressed in this study. Objective: To evaluate clinical-functional performance and upper limb stability control in young swimmers, establishing the relationship between these measures and subsequent musculoskeletal dysfunctions in the shoulder complex. Methods: This investigation comprised (1) a cross-sectional study and (2) a prospective cohort study. Thirty-two competitive swimmers (20 female), aged 13–16 years (min.–max.), were evaluated. Assessments included anamnesis, the Visual Analog Scale (VAS) for pain, the Western Ontario Shoulder Instability Index (WOSI), and the Upper Quarter Y Balance Test (UQ-YBT), performed on a force platform to record center of pressure (COP) displacements. In Study 1, functional performance and CoP displacements were compared between the preferred and non-preferred upper limbs, as defined by the
Edinburgh Handedness Inventory. In Study 2, musculoskeletal shoulder pain was recorded six months after the clinical-functional assessment, and associations between clinical-functional performance and pain occurrence were analyzed. Results: In Study 1, the best UQ-YBT performance was observed in the medial direction, with differences between upper limbs in the inferolateral (preferred > non-preferred) and medial (non-preferred > preferred) directions. Postural displacements did not correlate with performance, being greater in the superolateral direction, with no effect of limb preference. A significant correlation between performance and postural displacements was found only in the medial direction. In Study 2, 10 swimmers reported shoulder pain six months after the clinical-functional assessment. These individuals had higher WOSI and VAS scores, with no differences in anthropometric, training, functional performance, or balance variables. Logistic regression analysis identified WOSI, VAS, and age as significant predictors of subsequent pain. Conclusion: In young swimmers, UQ-YBT performance does not correlate with posturographic measures.
Postural displacements are influenced by task demand but not by limb preference. Clinical-functional outcome measures, such as WOSI and VAS, proved to be more significant predictors of subsequent shoulder pain than functional tests like the UQYBT.