Stroke patients often have a compromised gait pattern with kinematic deviations from normal walking, typically consisting of decreased hip-, knee-, and ankle dorsiflexion throughout the swing phase, and lack of stability in the paretic leg during the stance phase of gait.
The aim of this thesis was to design and develop a gait controller based on functional electrical stimulation to assist hemiparetic gait by combining muscle stimulation of quadriceps and soleus in the stance phase with elicitation of the nociceptive withdrawal reflex (NWR) from the sole of the foot to initiate the swing phase. Experimental studies were carried out to investigate the modulation of the NWR during normal gait (n = 4 participants) and hemiparetic gait (n = 1). The results indicated that the kinematic hip-, knee-, and ankle responses were dependent on stimulation site on the sole of the foot and stimulation on- set.
The modulatory effect of the NWR was utilised in the design of a sequence-based stimulation (SBS) controller to support hemiparetic gait. The performance of the SBS controller paradigm was tested (n = 1) against a simple paradigm composed of a fixed pattern of stimulation (FPS) controller. Overall, the SBS controller paradigm was superior in supporting the specific needs of the hemiparetic participant compared to the FPS paradigm.
The findings obtained in this thesis suggest that stroke patients may benefit from a stimulation paradigm where quadriceps and soleus are activated in the stance phase and the NWR elicited to initiate the swing phase during gait retraining.