Ankle Robot to Reduce Foot-drop in Stroke

Recruiting

Phase N/A Results N/A

Trial Description

Deficits in ankle control after stroke can lead to foot drop, resulting in inefficient, aberrant gait and an elevated falls risk. Using a novel ankle robot and newly invented adaptive control system, this study tests whether robotic assisted treadmill training will improve gait and balance functions in chronic stroke survivors with foot drop impairment. It is hypothesized that, compared to treadmill training alone, integrating adaptive ankle robotics with treadmill training will reduce drop foot during independent overground walking, resulting in greater mobility, improved postural control, and reduced fall risk.

Detailed Description

This proposal investigates a novel ankle robot (anklebot) adaptive control approach integrated with treadmill training to reduce foot drop and improve mobility function in chronic hemiparetic stroke survivors. Currently, stroke survivors with foot drop are trained to live with a cane or other assistive device, and often ankle foot orthotics (AFOs) for safety. Neither mediates task-practice or neuromotor recovery.
The investigators have developed an adaptive anklebot controller that detects gait cycle sub-events for precise timing of graded robotics assistance to enable deficit severity-adjusted ankle motor learning in the context of walking. The investigator's pilot findings show that 6 weeks treadmill training with anklebot (TMR) timed to assist swing phase dorsiflexion only is more effective than treadmill alone (TM) to improve free-walking swing dorsiflexion at foot strike, floor-walking speed, and the benefits are retained at 6 weeks post-training. Notably, swing-phase TMR training improved paretic leg push-off, and reduced center-of-pressure sway on standing balance, indicating potential benefits to other elements of gait and balance, beyond those robotically targeted toward foot drop.
This randomized study investigates the hypothesis that 6 weeks TMR is more effective to improve durably gait biomechanics, static, and dynamic balance, and mobility function in chronic stroke survivors with dorsiflexion deficits, compared to TM alone. Aims are to determine the compare effectiveness of 6 weeks TMR vs. TM alone on:
1. Independent gait function indexed by gait velocity, swing-phase DF, terminal stance push-off.
2. Balance function indexed by measures of postural sway (CoP), asymmetric loading in quiet standing, peak paretic A-P forces in non-paretic gait initiation, and standardized scales for balance and fall risk.
3. Long-term mobility outcomes, assessed by repeated measures of all key gait and balance outcomes at 6 weeks and 3 months after formal training cessation.

Conditions

Interventions

  • Treadmill plus anklebot Device
    Other Names: TMR
    Intervention Desc: This intervention employs the use of the adaptive anklebot control system to complement treadmill exercise training over a 6-week intervention period.
    ARM 1: Kind: Experimental
    Label: Treadmill+anklebot
    Description: This group will receive gait training on a treadmill while wearing the anklebot with the adaptive control system.
  • Treadmill only Behavioral
    Other Names: TM
    Intervention Desc: This intervention employs the use of a treadmill for gait exercise training over a 6-week intervention period
    ARM 1: Kind: Experimental
    Label: Treadmill only
    Description: This group will receive gait training on a treadmill, without use of the anklebot.

Trial Design

  • Allocation: Randomized
  • Masking: Single Blind (Outcomes Assessor)
  • Purpose: Treatment
  • Endpoint: Efficacy Study
  • Intervention: Parallel Assignment

Outcomes

Type Measure Time Frame Safety Issue
Primary Gait velocity during self-selected overground walking change from baseline to: post 6 weeks training, 6 weeks after completion of training, and 6 months after completion of training No
Primary Anterior-posterior propulsion forces of paretic side during gait Change from baseline to: post 6 weeks training, 6 weeks after completion of training, and 6 months after completion of training No
Primary Peak dorsiflexion angle during swing phase of gait Change from baseline to: post 6 weeks training, 6 weeks after completion of training, and 6 months after completion of training No
Primary Postural sway areas during quiet standing Change from baseline to: post 6 weeks training, 6 weeks after completion of training, and 6 months after completion of training No
Primary Ratio of asymmetric loading in quiet standing Change from baseline to: post 6 weeks training, 6 weeks after completion of training, and 6 months after completion of training No
Primary Peak paretic push off forces during gait initiation Change from baseline to: post 6 weeks training, 6 weeks after completion of training, and 6 months after completion of training No

Sponsors