Stimulation of the withdrawal reflex in gait training after stroke: A systematic review and meta-analysis

After a stroke many people experience hemiparesis, resulting in walking difficulties which affects independence, mobility, and participation in activities of daily living. Activating the nociceptive withdrawal reflex (NWR) during gait training aims to support the initiation and facilitation of the swing phase of the paretic leg. The aim of this review is to investigate the orthotic and therapeutic effects of a NWR stimulation intervention to improve gait in patients after a stroke.

We searched the databases CENTRAL, DORIS, MEDLINE, and PEDro, trial registers and reference lists. We selected randomized controlled trials using any type of stimulation of the NWR in people after stroke, comparing it to any control intervention, and reporting a change in gait performance assessed by means of any appropriate measurement method.

We included three studies in this review, all of which used electrical stimulation to elicit the NWR during walking. The orthotic effect was investigated in one study, and the therapeutic effect in two studies, comparing walking with and without electrical stimulation-triggered NWR. The meta-analysis revealed a borderline statistical significance result for the therapeutic effect. The pooled mean difference between the treatment and control group (random-effects model) for walking speed was 0.13 m/s (95% CI -0.04 to 0.29; I² = 72%) after treatment and 0.17 m/s (95% CI -0.03 to 0.37; I² = 62%) at follow-up.

Activating the NWR during gait training has not been investigated frequently so far. By using electrical stimulation-elicited NWR, severely affected hemiparetic patients may improve their walking speed.