Biofeedback to Increase Propulsion During Walking After Stroke
Condition: Stroke
MeSH terms: Stroke
Study type: Interventional
Phase: Phase 1

Summary: 
      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.
    

Intervention name(s): Gait Training with Biofeedback; Gait Training with Verbal Feedback
Intervention type(s): Procedure; Procedure
Intervention description(s): 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.; 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.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Parallel: participants are assigned to one of two or more groups in parallel for the duration of the study.
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Stroke; Gait; Walking; Rehabilitation; Exercise; Exercise Therapy; Physical Therapy Modalities; Exercise Movement Techniques