Reactive Balance Training and Fitness

Summary

People with stroke should exercise to maintain function and reduce the risk of another stroke. Different types of exercise target different components of fitness, such as aerobic, strength, and balance. Post-stroke exercise guidelines exist for each type of exercise separately (eg, brisk walking as aerobic exercise, resistance training for strength, and Tai Chi for balance). Meeting these recommendations means spending a lot of time exercising, and people with stroke say that lack of time and fatigue are barriers to exercise. It is possible to target several components of fitness with one type of exercise.

'Reactive balance training' (RBT) is a type of exercise that improves control of reactions that are needed to prevent a fall after losing balance, and is the only type of exercise with potential to prevent falls in daily life post-stroke. Because RBT involves repeated whole-body movements it may have similar aerobic benefit as other exercises using whole-body movements (eg, brisk walking). Also, leg muscles need to generate a lot of force to make rapid steps in RBT; repeatedly generating this force may help to improve strength.

The purpose of this study is to determine if RBT improves two important components of fitness among people with chronic stroke: aerobic capacity and strength. The investigators expect that the improvements in aerobic capacity and strength after RBT will not be any worse than after an exercise program that specifically targets aerobic fitness and strength. A secondary purpose of this study is to determine the effects of RBT compared to aerobic and strength training on balance control and balance confidence. The investigators expect that RBT will lead to greater improvements in balance control and balance confidence than an aerobic and strength training program.

Conditions

• CVA (Cerebrovascular Accident)

Interventions

OTHER

Reactive balance training

A variety of tasks will be included to induce external or internal perturbations. External perturbations will be caused by forces outside participants' control (e.g. a push or pull from the physiotherapist). Internal perturbations are when the participant fails to control the centre of mass-base of support relationship during voluntary movement; e.g., 'agility' tasks such as kicking a soccer ball. Each session will include a five-minute warm-up, at least 60 perturbations, and a five-minute cool-down. The difficulty of the task will be set such that participants will 'fail' to recover balance \~50% of the time; 'failure' is defined as use of an upper extremity response, use of external assistance (i.e. from the overhead harness or physiotherapist), or taking more than 2 steps to regain stability. Training tasks will progressed by increasing the perturbation magnitude, including cognitive or movement tasks, or imposing sensory or environmental challenges (e.g. eyes closed, obstacles).

OTHER

Aerobic and strength training (AST)

AST sessions will consist of 30 minutes of aerobic and 30 minutes of strength training. Aerobic training: Aerobic training will be done using treadmill walking or combination of modalities (e.g. cycling or recumbent stepping) for those unable to maintain the target heart rate with walking. The heart rate that occurred at the ventilatory threshold (V̇O2VT) during the cardiopulmonary exercise test will be used to prescribe intensity. In the absence of a discernible V̇O2VT a combination of the following will be used: 60-80% of heart rate reserve, peak oxygen uptake, and rating of perceived exertion of 11-16 (Borg 6-20 scale). Prescriptions will be initially progressed by increasing duration to ≥20 minutes and then increasing intensity to target heart rate. Resistance training: Participants will be prescribed 1-2 sets of 8 exercises per session (squat, heel raise, ankle dorsiflexion, knee extension and flexion, abdominal curl-up, wall push up, bicep curl), at 70% of 1 repetition maximum.

Sponsors & Collaborators

• University of Toronto

  collaborator OTHER

• Heart and Stroke Foundation of Canada

  collaborator OTHER

• Toronto Rehabilitation Institute

  lead OTHER

Principal Investigators

• Avril Mansfield, PhD · University Health Network, Toronto

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2019-09-01

Primary Completion

2024-05-28

Completion

2025-05-16

Countries

• Canada

Study Locations