Investigating the factors causing knee hyperextension in chronic stroke patients and the effects of rigid taping for the control of hyperextension through kinematic analysis

This study was conducted to determine the factors that cause knee hyperextension during the stance phase of gait in stroke patients and to examine the acute effect of rigid taping on hyperextension. 30 stroke patients between the ages of 40 and 70 were included in the study. The lower extremity muscle strength of the patients was evaluated with manual muscle testing, muscle tone with the Modified Ashworth Scale, and balance evaluation with the single-leg stance test. Clinical evaluation of gait was performed using the 10-meter walk test, and kinematic analysis was performed using the motion analysis system. On the second day of the study, rigid taping was applied to the patients' knees using the hyperextension taping technique and the gait analysis was repeated. In our study, a moderate relationship was found between maximum knee hyperextension degree and gastrocnemius spasticity, and a weak relationship was found between hip adductor spasticity. However, a moderate correlation was found between the degree of knee hyperextension and knee flexor muscle strength, and a weak correlation was found between ankle dorsiflexor muscle strength (p<0.05). Additionally, it was observed that increasing knee hyperextension was weakly associated with increasing pelvic retraction angle (p<0.05). It was found that rigid taping applied to the knee significantly reduced knee hyperextension and pelvic retraction (p<0.05). Our results showed that lower extremity spasticity and muscle forces are factors that cause knee hyperextension, and rigid taping application is effective in controlling knee hyperextension. Our results suggest that post-stroke knee hyperextension is a multifactorial disorder, and that rigid taping contributes to the reduction of knee hyperextension and increased pelvic retraction because it mechanically gives the knee a flexion moment and provides proprioceptive input. Keywords: Stroke, gait analysis, rigid taping, kinematic analysis, knee hyperextension.