Power Exercise for Stroke Recovery: The POWER Pilot Trial (POWER-P)

Official title

Power Exercise for Stroke Recovery: A Pilot Randomized Controlled Trial (POWER-Pilot)

Overview

Weakness is one of the most common consequences of stroke. For the over 750,000 Canadians living with stroke, many daily activities like standing from a chair, walking and balance not only require strength but often efforts in bursts, known as muscle power. Strength training can improve muscle strength and, when performed at higher speeds, can help build muscle power. Current guidelines for stroke recommend strength training but these are commonly performed at lower intensities and do not include any focus on building muscle power. There has been very little research on power training after stroke. A 10-week power training program for people living with stroke, Power Exercise for Stroke Recovery (POWER-Feasibility, NCT05816811) was recently evaluated. POWER includes 3 phases of progressive exercise: building familiarity with the upper and lower body exercises, then strength, and lastly muscle power. The results from POWER-Feasibility are promising, suggesting that POWER is safe and may improve stroke recovery. POWER-Feasibility was a small study (15 participants), and POWER was not compared to a control intervention. A pilot randomized controlled trial of POWER (POWER-Pilot) will now be conducted. Sixty people who are at least 6 months after stroke will be recruited. They will be randomly assigned to participate in POWER or standard strength training for stroke at lower intensities and without focus on power training. The feasibility of a randomized study will be examined, and whether POWER can improve walking, strength and balance compared to the control group. Results from POWER-Pilot will help design a larger randomized trial in the future (POWER-RCT), and may ultimately be important for stroke rehabilitation teams to better understand whether power training can help people recovering from stroke.

Detailed description

With the population aging, nearly 750,000 Canadians live with stroke, surpassing previous projections by 15 years. Post-stroke deficits, including loss of strength, balance and walking ability, are highly common. Sarcopenia, often associated with aging yet highly prevalent in stroke, underlie these deficits and contribute to lower discharge rates after hospitalization.

Community stroke exercise programs can improve strength and function to aid in recovery beyond hospital care. Most programs however follow conservative resistance exercise training (RET) approaches, as stroke guidelines are based on limited evidence. Unlike benefits of RET shown in mobility in older adults, stroke trials have shown large improvements in strength without concurrent changes in mobility, motor function or walking.

Power-focused RET involves moving lighter weights at high speed to develop muscle power, which may be more important than strength alone for activities critical for independent living such as climbing stairs, balance, and walking speed. A novel, progressive power training-focused community program for stroke (Power Exercise for Stroke Recovery, POWER) was developed to influence recovery of physical function. Following a successful single-group feasibility study of POWER (POWER-Feasibility, NCT05816811), a phase II pilot randomized trial (POWER-Pilot) is needed.

This pilot randomized trial aims to answer the following questions: 1) What is the feasibility of a multi-site randomized design to evaluate Power Exercise for Stroke Recovery (POWER), a power-focused training program for people living in the community with stroke? 2) What are the preliminary estimates of the effect of POWER compared to conventionally recommended RET (Strength Training Engaging Guidelines to Enhance Total Health, STRENGTH) for people living in the community with stroke on outcomes of functional mobility (walking, balance), post-stroke fatigue, psychological wellbeing, cognition, and health-related quality of life?

Sixty participants (6 months post-stroke, completed rehabilitation) will be randomized to POWER or STRENGTH. POWER involves 3 progressive phases: 1) Familiarization (1 week), 2) Strength (4 weeks, 2-3 sets, 5-8 repetitions), and 3) Power (5 weeks, 2-3 sets, 15-20 repetitions, fast tempo). STRENGTH is based on current RET clinical practice guidelines for stroke with no focus on power. POWER and STRENGTH matched in length, frequency (3x/week) and format (in-person supervision) but differentiated by approach to exercise progression, intensity, and tempo.

Feasibility indicators such as randomization and blinding have predefined success and progression thresholds. Estimates of the effect of POWER include functional mobility (Timed Up and Go, primary clinical outcome), walking speed, post-stroke fatigue, psychological well-being, cognition, balance, and quality of life, and will be assessed pre-post, and at 8-week follow-up. Sex and gender-related factors associated with feasibility and changes in clinical outcomes as social determinants of exercise participation post-stroke will also be examined.

Feasibility outcomes and effect estimates from POWER-Pilot will guide scalability for a fully powered RCT and future cost-effectiveness evaluation, shaping exercise best practices and facilitating hospital-to-community transition through broader implementation in community programs.

Interventions

• Other Power Exercise for Stroke Recovery (POWER)
  POWER incorporates 3 progressive phases: Phase 1 Familiarization (Week 1) as a low-intensity version of the training program to acclimate participants to the movements (body weight resisted or light weights, RPE 2-3 "Fairly light" to "Moderate"). Phase 2 Strength (Weeks 2-5) progresses loads to achieve volitional fatigue within 6-8 repetitions (RPE 7-9 "Very hard" to "Very very hard"). Phase 3 Power (Weeks 6-10) will use intensities RPE 4-6 ("Somewhat hard" to "Very hard"), and exercises will be
• Other Strength Training Engaging Guidelines to Enhance Total Health (STRENGTH)
  STRENGTH is based on current clinical practice guidelines for RET after stroke. It will include the same Familiarization week as the POWER program (Week 1), followed by progressive conventional RET involving 3 sets of 10-15 repetitions at moderate to high intensities (RPE 4-5 "Somewhat hard" to "Hard") (Weeks 2-10). The external resistance will be progressed to maintain this target RPE range. STRENGTH is matched with POWER in length (60-minute sessions over 10 weeks), frequency (3x/week) and for

Primary outcome measures

• Feasibility: Randomization - Percentage of participants allocated as assigned [Time frame: Through study completion, over 24 months]
• Feasibility: Randomization - Clinically important difference between groups [Time frame: Through study completion, over 24 months]
• Feasibility: Allocation concealment [Time frame: Through study completion, over 24 months]
• Feasibility: Assessor blinding - Number of occurrences of unblinding [Time frame: Through study completion, over 24 months]
• Feasibility: Contamination - Number of participants exposed to other intervention arm [Time frame: Through study completion, over 24 months]
• Feasibility: Recruitment rate - Number of participants recruited per month [Time frame: Through study completion, over 24 months]
• Feasibility: Retention rate - Percentage of participants with follow up data [Time frame: Through study completion, over 24 months]
• Feasibility: Participant and assessor burden - Percentage of participants completing study assessments in ≤1.5h [Time frame: Through study completion, over 24 months]
• Feasibility: Participant and assessor burden - Participant rating of the burden of assessments [Time frame: Through study completion, over 24 months]
• Feasibility: Safety - Number of serious adverse events [Time frame: Through study completion, over 24 months]

Secondary outcome measures (12)

• Walking speed: 10-meter walking speed (self- and fast-paced) [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]
• Post-stroke fatigue: Fatigue Severity Scale-7 (FFS) [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]
• Psychological well-being: General Health Questionnaire-28 [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]
• Cognition: Montreal Cognitive Assessment (MoCA) [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]
• Standing balance: Brief Balance Evaluation System Test (Brief BESTest) [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]
• Standing balance: Berg Balance Scale (BBS) [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]
• Health-related quality of life: Stroke Impact Scale 3.0 (SIS 3.0) [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]
• Health-related quality of life: EuroQol-5D-5L (EQ-5D-5L) [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]
• Participation: Measure of Experiential Aspects of Participation (MeEAP) [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]
• Lower extremity strength and endurance: 30-second chair stand test (30sCST) [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]
• Self-efficacy for balance: Activities-Specific Balance Confidence Scale (ABC) [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]
• Confidence in exercising: Exercise Self-Efficacy Scale (ESES) [Time frame: Baseline (0 weeks), post-intervention (10 weeks), follow-up (18 weeks)]

Eligibility criteria

Inclusion criteria

• ≥19 years old
• ≥6 months poststroke,
• able to walk >10 meters with or without an assistive device
• have mild to moderate stroke severity (modified Rankin Scale ≤3)
• without significant cognitive impairment that would preclude safe exercise, screened via Montreal Cognitive Assessment-Blind score <18

Exclusion criteria

• Any contraindications to exercise for people with cardiovascular disease, such as unstable angina, uncontrolled hypertension, orthostatic blood pressure with exercise, or uncontrolled arrhythmias or
• Actively engaged in or have made plans to engage in stroke rehabilitation services

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Other

Study locations

Canada · 2 centers

• The University of British Columbia - Okanagan Campus — Kelowna
• McMaster University — Hamilton

Identifiers

NCT: NCT06780995 · POWER-Pilot

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗