Identification of stiff-knee gait in stroke survivors

Abstract Background: Though stiff-knee gait is a common movement disorder in individuals with stroke, the criteria for identifying it in this population are not yet well established. This study investigated suitable criteria to identify stroke survivors with stiff-knee gait. Twenty-four stroke survivors (45.2±13.7 years old) and 24 individuals matched by age and sex (45.5±13.5 years old) with no known gait impairment participated in this study. They walked along a 10-m extension walkway at a self-selected comfortable speed. A computerized analysis system registered the trajectories of retroreflective markers placed on specific body landmarks, and different measurements were calculated regarding knee flexion during gait cycle, such as its peak during the swing period, total range of motion (RoM), equivalent to the difference between maximum and minimum knee excursion during gait cycle (“RoM cycle”), and RoM from toe-off to peak knee flexion (“RoM swing”). Results: Overall, peak knee flexion during the swing period and knee RoM swing were the most remarkable measurements to identify stiff-knee gait in stroke survivors. Conclusions:Based upon the found results, we suggest using at least two criteria to identify stiff-knee gait in individuals with stroke. The most suitable ones are peak knee flexion during the swing period <50° and the knee RoM from toe-off to peak knee flexion <12°. Finally, our results suggest that it is inappropriate to consider the non-paretic limb and total knee flexion RoM to classify stiff-knee gait in individuals with stroke.