The pursuit of better athletic performance has become frequent in sports practice. Therefore, it is fundamental to use functional tests in the evaluation process to assess functional capacity and implement more assertive interventions. The Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) is a test that evaluates upper limb performance and is consolidated as a reliable measure for clinical application. It is known that various factors such as muscle activation, flexibility, trunk stability, and lower limb strength can influence shoulder complex movement efficiency. However, the relationships between functional tests in identifying or measuring factors related to upper limb performance have not been clarified in the literature.

To identify whether trunk and lower limb strength factors predict upper limb functional capacity.

The database of the Physiotherapy Assessment Tool (PHAST) application was used for the development of this study. Thirty-six healthy participants of both sexes, aged between 25 and 62 years, were included, containing evaluation records with information on performance in CKCUEST, Scapulohumeral Rhythm, Shoulder Strength External, Lateral Rotation Range of Motion, Prone Bridge Test, Pelvic Elevation, Latissimus Dorsi Flexibility and Pectoralis Minor Muscle Tightness, and Torque Knee Isokinetic. Multiple linear regression analysis was performed to identify whether trunk stability and lower limb strength could explain upper limb performance and functional capacity.

The results revealed a statistically significant model for, Scapulohumeral Rhythm, Shoulder Strength External, Lateral Rotation Range of Motion, Prone Bridge Test, Pelvic Elevation, Latissimus Dorsi Flexibility and Pectoralis Minor Muscle Tightness, and Pelvic Elevation predicting 46% of CKCUEST performance (F=7.28, R=0.684, R2=0.468, P=0.008). Additionally, the inclusion of Hamstring Torque in the model (F=8.27, R=0.735, R2=0.541, P=0.003) predicted 54% of CKCUEST performance. No other associations were observed.

Scapulohumeral Rhythm, Shoulder Strength External, Lateral Rotation Range of Motion, Prone Bridge Test, Pelvic Elevation, Latissimus Dorsi Flexibility and Pectoralis Minor Muscle Tightness, and Pelvic Elevation with Hamstring Torque Strength, partially predicted performance in CKCUEST.

The findings of this study suggest that clinicians should use lower limb strength and trunk and pelvis stability tests as a complement to shoulder evaluation. Additionally, future studies should investigate the influence of other factors associated with these functional tests.