Biofeedback to Increase Propulsion During Walking After Stroke

Recruiting

Phase 1 Results N/A

Trial Description

Approximately 15,000 Veterans are hospitalized for stroke each year with new cases costing an estimated $111 million for acute inpatient, $75 million for post-acute inpatient, and $88 million for follow-up care over 6 months post-stroke. Rehabilitation of walking ability contributes to these costs. To "walk again" is the number one stated goal for Veterans who have had a stroke. Teaching patients post-stroke to use their weak leg while they are regaining walking function and to not compensate by over-using their strong leg is necessary to restore safe, efficient walking ability. This project will determine if providing biofeedback (an audible tone) from pressure-sensitive shoe insole sensors, that encourage use of the weaker leg during walking training, in addition to therapists' feedback, will help Veterans regain use of their weak leg, improve their endurance and improve their balance when walking in challenging environments.

Detailed Description

Background/Purpose: Approximately 15,000 Veterans are hospitalized for stroke each year. Impairments of motor control and the subsequent functional limitations in ambulation are the most common manifestations and regaining the ability to walk is the number one stated goal of Veteran stroke survivors. Forward propulsion of the body's center of mass is a cardinal feature of gait that depends on the generation of appropriate anterior-posterior ground reaction forces. Decreased propulsive force generation by the paretic limb of stroke survivors has been identified through both simulation and cross-sectional studies as a major contributor to walking dysfunction. Extrinsic verbal feedback from a therapist is the standard approach used during gait retraining to improve propulsion generation. However, this key component of gait is not directly observable by therapists and patients are often unable to sense propulsion generation due to impaired intrinsic feedback, specifically deficits in somatosensation and proprioception, hindering recovery of paretic propulsion and compromising walking function. The objective of this study is to provide preliminary evidence that biofeedback as an adjuvant to therapists' verbal feedback will improve propulsion and enhance walking function for Veterans post-stroke.
Subjects: Thirty individuals > 6-months post-stroke will participate. Additional study criteria include: 1) Ambulation of household distances without physical assistance to advance or support the paretic leg; 2) Unilateral leg paresis confirmed by a score of < 32 on the Fugl-Meyer Motor Assessment; 3) Step length asymmetry (paretic > non-paretic step length); 4) Ambulation without an assistive or orthotic device.
Methods: Participants will be randomized to either an experimental group that will train with propulsion biofeedback from commercially available pressure-sensitive insole sensors (Biofeedback group; n=15) or a control group that will train with standard therapist-provided verbal feedback alone (Standard group; n=15). The 12 session (3X/week for 4 weeks) gait training intervention will be delivered by a physical therapist-led team. For participants in the Biofeedback group, prior to the first intervention session, the baseline amount of pressure exerted by the paretic forefoot during late stance will be determined. The insole area underlying the forefoot will then be calibrated to produce a tone when pressure exceeds 5% of this baseline pressure. This threshold will be progressively increased at regular intervals throughout the intervention period to ensure participants are training at their challenge-point to improve propulsion of the paretic limb. An insole of similar thickness will be worn in the shoe of the non-paretic leg for symmetry and comfort but will not produce a tone during the intervention. Those in the Standard group will not wear insoles during intervention but will receive verbal feedback alone regarding propulsion of the paretic limb during gait training. Therapist-provided verbal feedback will be used to instruct participants on achieving and/or maintaining appropriate movement patterns that contribute to propulsion generation. For both groups, the therapist will choose from a standardized bank of gait activities, suitable to each participant's ability level. The goal for total walking time for each session will be 50 minutes: 5, 10-minute bouts with a 2-minute rest between each bout.
Outcome Measures: Paretic limb propulsion is the primary outcome measure. Secondary measures include the Six Minute Walk Test, Functional Gait Assessment, Fall Self-Efficacy, temporal-distance gait measures and gait kinematics, all of which will be measured pre- and post-intervention.
Data Analysis Plan: Descriptive statistics will be provided for all outcome measures. To identify the effect of the intervention, differences between the pre- and post-training assessment within each group (i.e. change scores) will be calculated. To test the hypotheses, the investigators will apply independent sample t-tests to the change scores of the Biofeedback and Standard group. Hypothesis testing will be conducted at a two-sided p < 0.05 level.

Conditions

Interventions

  • Gait Training with Biofeedback Procedure
    Intervention Desc: Intervention (12, 60-minute sessions, 3X/week for four weeks) will occur in an outpatient research setting. Participants will be supervised by a licensed physical therapist and wear a gait belt during all activities. The therapist will choose from a standardized bank of gait activities, suitable to each participant's ability level. The goal for total walking time for each session will be 50 minutes: 5, 10-minute bouts with a 2-minute rest between bouts. This is the typical length and intensity of outpatient rehabilitation sessions for ambulatory patients discharged from inpatient rehabilitation. Biofeedback Group: Biofeedback (external-focus feedback) will be provided as an adjuvant to therapist-provided feedback during the intervention. Participants will be instructed that a tone will sound when they "push off with their (paretic) leg to swing it forward" when the participant-specific pre-programmed threshold is exceeded.
    ARM 1: Kind: Experimental
    Label: Biofeedback Group
    Description: Participants will wear a pressure-sensitive insole inside the shoe of their paretic limb. An auditory tone will sound when participants have provided sufficient load to active the pressure-sensitive in-sole.
  • Gait Training with Verbal Feedback Procedure
    Intervention Desc: Intervention (12, 60-minute sessions, 3X/week for four weeks) will occur in an outpatient research setting. Participants will be supervised by a licensed physical therapist and wear a gait belt during all activities. The therapist will choose from a standardized bank of gait activities, suitable to each participant's ability level. The goal for total walking time for each session will be 50 minutes: 5, 10-minute bouts with a 2-minute rest between bouts. This is the typical length and intensity of outpatient rehabilitation sessions for ambulatory patients discharged from inpatient rehabilitation. Verbal Feedback Group: Therapist-provided internal-focus feedback ("directed towards components of body movement") will be used to instruct participants on achieving and/or maintaining appropriate movement patterns that contribute to propulsion generation.
    ARM 1: Kind: Experimental
    Label: Verbal Feedback Group
    Description: Participants will receive verbal feedback from a physical therapist regarding the amount of loading they are exerting on their paretic limb.

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 Change in Paretic Limb Propulsion from pre to post-intervention Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No
Secondary Change in Hip, knee and ankle motion data from each leg from pre to post-intervention Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No
Secondary Change in stride time from pre to post-intervention. Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No
Secondary Change in Electromyography of the soleus and medial gastrocnemius muscles of both legs from pre to post-intervention Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No
Secondary Change in Six Minute Walk Test from pre to post-intervention Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No
Secondary Change in Functional Gait Assessment from pre to post-intervention Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No
Secondary Change in Modified Falls Efficacy Scale from pre to post-intervention Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No
Secondary Change in step time from pre to post-intervention. Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No
Secondary Change in stride length from pre to post-intervention. Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No
Secondary Change in step length from pre to post-intervention. Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No
Secondary Change in step width from pre to post-intervention. Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No
Secondary Change in gait speed from pre to post-intervention. Pre-intervention (prior to 1st intervention session) and Post-intervention (after the final (12th intervention session), approximately 4 weeks after entering the study. No

Sponsors