Research in Focus: Ankle-foot Orthoses and Continuous Functional Electrical Stimulation Improve Walking Speed After Stroke

  •   November 5, 2020

Full citation

Nascimento LR, da Silva LA, Araujo Barcellos JVM, Teixeira-Salmela LF, Ankle-foot Orthoses and Continuous Functional Electrical Stimulation Improve Walking Speed After Stroke: A Systematic Review and Meta-analyses of Randomized Controlled Trials, Physiotherapy (2020), doi: https://doi.org/10.1016/j.physio.2020.08.002

Background

Stroke is the leading cause of death and disability in Canada, with 36% of survivors experiencing persistent, significant disabilities five years after stroke.1 “Balance impairments and reduced walking speed are two of the main disabilities after stroke” and are “associated with restrictions in social participation.”2 Foot drop, characterized by inefficient foot clearance in the swing phase of gait and reduced stability during the stance phase, affects 20-30% of individuals with stroke.2 Both ankle-foot orthoses (AFOs) and functional electrical stimulation (FES) have been used to improve foot drop and its related balance and gait impairments.

The objective of the study was to examine the effectiveness of ankle-foot orthoses and functional electrical stimulation on walking speed and balance after stroke.

Methods

Study design:

  • Systematic review, registered at PROSPERO conducted in accordance with PRISMA guidelines.
  • Literature search:
    • Databases: Medline, EMBASE, Cochrane, PsycINFO, PEDro.
    • No date or language restrictions.
  • Quality was determined by extracting PEDro scores. If a trial was not included on the PEDro database, it was scored by a reviewer who had completed PEDro scale training.
  • Inclusion Criteria: ≥ 80% of the sample of any study included comprised ambulatory participants.
  • Population: ambulatory adults (walking speed ≥ 0.2m/s at baseline or when able to walk without help, with or without gait aid), at any time post-stroke.
  • Intervention: AFO or FES, applied throughout the day, to reduce foot-drop during gait in people with stroke. Control group varied with each included study.
  • Outcomes of Interest: walking speed and balance.   
  • 11 studies were included in the review, including:
    • 2 compared AFO with no intervention for gait speed (both studies included this comparison) and balance (both studies included this comparison)
    • 5 compared FES with no intervention for gait speed (all 5 studies included this comparison) and balance (only 1 study included this comparison)
    • 4 comparing AFO and FES for gait speed (all 4 studies included this comparison) and balance (only 2 studies included this comparison)
  • Eight studies included additional rehabilitation to both groups (intervention and control).

Data analysis

  • Pooled estimate of effect based on post-intervention scores or change scores
  • Random effects model used
  • I2 statistic calculated to determine proportion of variance due to heterogeneity
  • GRADE system was used to summarize overall quality of evidence

Findings

Quality:

  • Mean PEDro score of included studies was 5.8 (range 4-7)
    • Most included trials did not have blinded assessors and did not report intention-to-treat analysis.
    • None of the trials blinded participants or therapists.

Q1: Do AFOs improve gait speed and balance after stroke?

  • Moderate quality evidence of significant increase in walking speed (0.24m/s) compared with no intervention
    • Exceeds MCID (estimated to be between 0.1 to 0.2m/s3)
    • Pooled post-intervention data from two trials (61 participants)
  • Contradictory, low-quality evidence regarding impact of AFO on balance
    • Pooled post-intervention data from two trials (61 participants)

Q2: Does FES improve gait speed and balance after stroke?

  • Moderate quality evidence of statistically significant increase in walking speed (0.09m/s) compared with no intervention
    • Does not reach MCID (estimated as 0.1 to 0.2m/s3)
    • Pooled post-intervention data from four trials (125 participants)
  • Effect of FES on balance could not be determined due to insufficient data from 1 trial

Q3: Are AFOs and FES similarly effective for improving walking speed and balance after stroke?

  • Moderate quality evidence of no difference between AFO and FES for improving walking speed after stroke
    • Pooled post-intervention data from four trials (895 participants)
  • High quality evidence of no difference between AFO and FES for improving balance after stroke
    • Pooled post-intervention data from two trials (692 participants)

Limitations

Clinicians should be very cautious when drawing conclusions based on this review.

  • Most of the trials did not include blinded assessors nor intention-to-treat analysis.
  • Rehabilitation was provided in addition to the intervention (AFO, FES) in seven trials. While clinically relevant, this makes it difficult to ascertain the intervention’s true effect.
  • Risk of small trial bias due to limited sample size of some of the included studies and small pooled sample sizes.
  • No follow up assessment to determine maintenance of effects beyond the trial period.
  • The authors did not comment on the risk of publication bias and presented no funnel plot.

Discussion

Additional well-designed, large trials are required to clearly demonstrate the effects of AFO or FES on balance, and to establish if AFO and FES provide comparable benefits for gait and balance outcomes. Until further evidence is available, clinical decisions should be made with due considerations of patient preferences, costs, and adverse effects of the interventions.

Relevance to physiotherapy practice in Alberta

AFO is a commonly available intervention and FES is increasingly available and employed in Alberta for individuals with foot drop following stroke. Clinicians must be aware of the research outcomes related to the use of FES and AFO when making clinical recommendations. Clinicians must also be aware of the limitations of the existing evidence when making recommendations regarding either intervention.

Disclaimer

The purpose of this summary is to highlight recently published research findings that are not openly accessible. Every effort is made to ensure accuracy and clarity of the summary. Readers are encouraged to review the published article in full for further information.


  1. Physiotherapy Alberta – College + Association. Physioworks: Stroke. Available at: https://www.physiotherapyalberta.ca/xchange/evidence_based_practice_resources/physiotherapy_works/stroke Accessed October 21, 2020.
  2. Nascimento LR, da Silva LA, Araujo Barcellos JVM, Teixeira-Salmela LF, Ankle-foot Orthoses and Continuous Functional Electrical Stimulation Improve Walking Speed After Stroke: A Systematic Review and Meta-analyses of Randomized Controlled Trials, Physiotherapy, 2020, doi: https://doi.org/10.1016/j.physio.2020.08.002
  3. Bohannon RW, Glenney SS. Minimal Clinically Important Difference for Change in Comfortable Gait Speed of Adults with Pathology: A Systematic Review. Journal of Evaluation in Clinical Practice, 2014 Aug; 20(4):295-300. doi: 10.1111/jep.12158. Epub 2014 May 5. PMID: 24798823.