Influence of Isokinetic Knee Muscle Torque at Different Angular Velocities on Standing Posture Stability in Healthy Adults

Abstract

Abstract Objectives Knee muscle groups contribute to proper and safe static and dynamic standing posture stability. The impact of isokinetic knee muscle torque at various angular velocities on standing posture stability is poorly understood. We investigated the influence of isokinetic knee muscle torque at different angular velocities on standing posture stability. Design Cross-sectional study. Setting King Saud University Campus labs. Method The study population was a convenience sample of 30 healthy volunteer college students with a mean age of 20±2 years. Isokinetic concentric peak torque (PT) of knee extensor (Q) and flexor (H) muscle groups as well as the flexor to extensor (H:Q) ratio at three different angular velocities: (60, 180, and 300°/s) were measured, respectively. The postural stability was also measured in both static and dynamic components. The Pearson correlation coefficient was used to examine the association between the different isokinetic components and postural stability (both static and dynamic). Results The PT of Q and H muscle groups and the H:Q ratio at the 3 different angular velocities were significantly associated with static standing balance with eye open on a firm surface (p<0.033). Moreover, the PT of Q at 60 and 180°/s angular velocities was significantly associated with maximum and endpoint excursion components of dynamic standing balance (p<0.044). Conclusions The PT of both Q and H muscle groups at different angular velocities are associated with maintenance of standing static balance. PT of Q only is significantly associated with control of dynamic standing balance in the lower angular velocities.