Treadmill Integrated Robot-assisted Ankle Dorsiflexion Training for Stroke Rehabilitation: A Pilot Randomized Controlled Trial

Ankle hemiparesis is a common post-stroke problem that impairs walking and exoskeletal robots are an emerging joint-specific tool that can address ankle deficits and automate therapy. This single-blind randomized controlled trial compared 6-week treadmillankle robot (TMR) training to 6-week treadmill (TM) only training on paretic ankle motor control and gait performance. Fortyfive participants with chronic stroke (>5 months to 6+ years) trained three times per week for six weeks. The groups were not statistically different at baseline, however, more TMR participants used ankle foot orthosis (AFO) (61%TMR; 36% TM). The primary analysis was based on intention-to-treat using a longitudinal regression model and analyzed post-training outcomes at week-six and at retention six-weeks and three-months after training. We found no significant between group ankle dorsiflexion (DF) and gait velocity change at week-six or at retention. The six-week mean peak paretic DF swing angle was 4.84 degrees (SD 6.83) and 4.2 degrees (SD 6.83) p=0.63 and the DF angle at foot strike was -0.70 degrees (SD 6.55) and -0.46 degrees (SD 5.70) p=0.84, respectively, in TMR and TM. Within group gait velocity improvement was similar with a mean increase of 0.54 m/s (SD 0.24) and 0.56 m/s (SD 0.32) p=0.48 in TMR and TM respectively, that was durable through retention. Integrating ankle robot training with TM walking was not significantly better than treadmill training alone. Future larger studies with refined eligibility criteria and randomization strata that balance key gait determinates are needed to further determine effectiveness on ankle function and gait.