Muscle activation patterns of knee flexors and extensors during passive and active movement of the spastic lower limb in chronic stroke patients.

The aim of this study was to describe the characteristics of spasticity, quantified as muscle activity during stretch, during passive and active movement. For this cross sectional study 19 stroke patients with spasticity in the lower limb were recruited. Reflex activity was studied with surface electromyography of knee flexor and extensor muscles during passive and active movement of the lower leg. On both the affected and unaffected side, root mean square values of the knee extensor muscles, while stretched, were higher during active than during passive movement (p<0.05). For the vastus lateralis (VL) the correlation was moderate (rho=0.54, p=0.022), for the rectus femoris (RF) high (rho=0.83, p