Isokinetic outcome measures and functional performance: Evaluating the utility of the 5-times squat-to-stand test

Objectives: The primary objective of this study was to examine the association between isokinetic knee extensor performance measures and the 5-Times Squat-to-Stand Test (5×SqTST) in healthy female college students. The second objective was to compare isokinetic outcome measures and 5-times squat-to-stand performance between recreationally active and inactive college students. Methods: A cross-sectional study was conducted involving 54 students. Participants underwent isokinetic testing of the dominant lower limb at angular velocities of 60°/s and 180°/s using a Biodex dynamometer to obtain peak torque, average torque (Nm), and average power during concentric quadriceps contractions. Functional performance was assessed using the 5×SqTST under eyes-open and eyes-closed conditions. Results: Spearman’s correlation analysis demonstrated a moderate negative association between the functional performance and isokinetic average power, significant at 180°/s ( P = −0.39, P = 0.003) but not at 60°/s ( P = −0.24, P = 0.08), indicating that longer task completion times were associated with lower muscle power at higher velocity. The Wilcoxon signed-rank test revealed statistically significant differences ( P < 0.001), with higher isokinetic average power at 180°/s, despite the lower torque values observed at the higher velocity. The Mann–Whitney U test demonstrated no significant differences in either functional or isokinetic measures between recreationally active and inactive participants (P > 0.05). Conclusion: The 5×SqTST demonstrated significant associations with isokinetic lower-limb power, supporting its use as a practical tool for estimating muscle performance in settings lacking laboratory equipment. Recreational activity status did not significantly impact outcomes in this cohort of female college students.