Impairments to locomotion can severely impact quality of life. In order to design and implement an intervention focused on gait impairments, the event needs to be detected objectively. Thus, a literature review was performed on methods to detect motor symptoms in real-time. However, our initial data collection didn’t produce impaired gait events needed to develop a classifier. Therefore the research shifted to ways of modifying gait.

Previous research showed the use of rhythmic electrical stimulation improved gait in individuals with Parkinson’s disease. Before testing a patient group, it’s important to understand the effect on non-impaired individuals. We first investigated whether entrainment of gait would occur in response to rhythmic electrical stimulation of the medial gastrocnemius with a period equal to natural stride period. We found that most subjects entrained with phase-locking near ankle push-off or near heel strike. We also investigated the electromuscular response of electrical stimulation of the medial gastrocnemius throughout the gait cycle. We found the largest effect in early stance and throughout the swing phase, but no augmentation was found when applied at push-off.

Next a dynamic walking model was created based on previous literature to observe entrainment of gait for unilateral and bilateral plantarflexor or dorsiflexor perturbations with perturbation periods ± 20 ms and ± 10 ms from the natural stride period. The model showed that shorter plantarflexion perturbation periods entrained near the end of double stance and longer plantarflexion perturbation periods entrained just before foot contact. The model typically entrained to dorsiflexor perturbations before the start of double support. The model entrained to shorter perturbations earlier in stance and entrained to longer perturbations later in stance. Applying the perturbation bilaterally shifted the timing to reduce its effect.

Experimental results showed that the period of the rhythmic electrical stimulation of the medial gastrocnemius and tibialis anterior was the only significant factor leading to entrainment. Entrainment occurred least frequently when the stimulation period was shorter than natural stride period. An analysis of stride period change due to the electrical stimulation showed stride period usually increased for all conditions, suggesting electrical stimulation is better suited for decreasing cadence.