The association between ankle joint function and knee hyperextension during the stance phase of gait in hemiparetic stroke patients: a pilot study
Knee hyperextension is common following stroke which clinicians hypothesise could be due to changes in muscle strength, muscle tone, and joint range of motion on the hemiparetic side. There is no clear consensus as to the cause of knee hyperextension during stance phase of gait. This pilot study’s aim is to determine the feasibility of the methods in order to investigate the association between ankle joint function and hyperextension of the knee in hemiparetic stroke patients during stance phase of gait in a larger study. This was a pilot study of a cross-sectional observational study design and assessed bilateral ankle muscle strength using a handheld dynamometer, joint range of motion (ROM) using a digital inclinometer, and muscle tone using the Modified Tardieu Scale. The knee angles of the hemiparetic leg during the three sub-phases of stance phase of gait (initial contact, loading response, and midstance) were assessed using the Kinovea movement analysis software. The data was analysed using the Statistical Package for the Social Sciences v27 with significance level set at p< 0.05. The researcher included 12 participants and found positive associations between the tibialis anterior muscle tone and the hemiparetic knee angles during heel strike, terminal stance and pre-swing phases (p < 0.05, p < 0.01 and p < 0.01 respectively). The results of the data analysis showed that there was no association between muscle strength and range of motion of the ankle, and knee hyperextension during stance phase of gait. Decreased tibialis muscle tone was seen in participants who presented with increased knee flexion during stance phase and does not seem to not play a role in knee hyperextension. But conclusions cannot be drawn from these results based on the small sample size and the heterogeneity of the participants. The researcher has shown feasibility of the methods described in this study for a larger study to be conducted with the recommendations considered.
A research report submitted in partial fulfilment of the requirements for the degree of Master of Science in Physiotherapy to the Faculty of Health Sciences, School of Therapeutic Sciences, University of the Witwatersrand, Johannesburg, 2021