Abstract
Aim: The purpose of the present study was to investigate the effect of different test positions on the static strength of ankle joint muscles and the EMG activity of the calf and thigh muscles in patients with upper motor neuron lesion due to stroke.
Set-up: Static torque was recorded during isometric plantar flexion muscle action while sitting, standing and lying prone, in both the affected and the non-affected leg in seven patients. The EMG activity was recorded in the soleus, medial gastrocnemius, anterior tibial and rectus femoris muscles.
Results: The affected leg showed lowered torque values in all positions compared to the non-affected leg. There were no significant differences in the torque values depending on positions nor in the EMG recordings. When the standing position was used as "normative", there was a significant difference in the EMG values between the affected and non-affected leg when sitting with the knee bent and while standing with the knee straight; i.e. in closed-chain exercises.
Discussion: Training and testing of strength in the plantar flexor muscles in stroke patients may be done in both open and closed-chain exercises as far as force development is concerned. However, the outcome of these different types of exercises might be influenced by the position of the knee joint since the gastrocnemius is a two-joint muscle.