Principal Investigator: Heather  Hayes
Keywords: cycle , stroke , symmetry , gait Department: Physical Therapy/Athletic Training
IRB Number: 00135445 Co Investigator: Jim  Martin
Specialty: Physical Therapy
Sub Specialties:
Recruitment Status: Enrolling by invitation

Contact Information

Heather  Hayes

Brief Summary



Stroke is a major health problem and a leading cause of long-term disability, such as impaired mobility, in the US. 1 Consequently, national funding agencies have considerable interest in funding stroke rehabilitation research. 

         Improving walking performance is a major goal post-stroke which can facilitate patients returning to their productive lives, thereby reducing cost to society. Stroke survivors usually have impaired, asymmetric walking with decreased stance phase and prolonged swing phase on the paretic side, decreased stride length, and decreased walking speed.2 Weight shifting in the frontal plane onto the hemiparetic leg is reduced by as much as 25-43% of body weight.3 These gait asymmetries place stroke survivors at a high risk for falls and have an increased energy cost.  4 Traditional rehabilitation techniques have demonstrated limited efficacy in reducing the hemiparetic gait asymmetry.5

         Cycling with power biofeedback (BFB) has great potential for improving walking post-stroke. Cycling and walking share similar kinematic patterns, but, in a recumbent position, patients are safer than in upright walking training, and instrumented pedals can provide BFB. BFB provides quantitative information about difficult-to-perceive parameters, such as power symmetry. Our prior research has shown that cycling with power BFB improves cycling power symmetry in individuals with gait asymmetries after anterior cruciate ligament reconstruction. We believe that cycling with power symmetry BFB can produce similar improvements in individuals post-stroke. Recumbent cycling with BFB is safe and feasible for individuals with chronic stroke (> 6 months). 6 Our goal is assess cycling with power symmetry BFB in individuals early after stroke (2 - 20 days post-stroke), the time period when most recovery occurs and ingrained compensatory asymmetries develop. We will test this intervention early in rehabilitation capitalizing on heightened neuroplasticity and perhaps preventing entrenched asymmetry 7-9 through the following three Specific Aims.


Aim 1. Determine the change in cycling power using BFB on a group of individuals with stroke in an Inpatient Rehabilitation Facility. Approach. Participants from the University of Utah Craig H. Neilsen Rehabilitation Hospital will be randomized into 2 groups; 1) traditional rehabilitation; 2) traditional rehabilitation + cycling with power BFB. We seek to determine the change in cycling power output for individuals’ early post-acute stroke.  Expected outcome. We expect that individuals provided BFB about cycling power will demonstrate improved power symmetry pre- to post-cycle intervention.


Aim 2. Determine the effect size of the change in gait symmetry with cycling training with power BFB pre- to post-cycle intervention. Approach. Participants will be assessed on gait symmetry patterns using a wearable sensor system (APDM®) for gait kinematic analysis pre- and post-intervention. Expected outcome. We expect the cycling with BFB (in conjunction with traditional rehabilitation) will improve interlimb symmetry during walking.


Aim 3. Determine the effect size of the change in functional mobility with cycling training with power BFB pre- to post-cycle intervention. Approach. Participants will be assessed on gait speed (10-meter walk test) and endurance (6-minute walk test) pre- and post-intervention. Expected outcome. We expect the cycling with BFB will have greater improvement in walking speed and 6-minute walk compared to traditional rehabilitation alone.


Detailed Description

Stroke is a leading cause of serious long-term disability.1 Walking dysfunction occurs in greater than 80% of stroke survivors.Consequently, gait impairments cause difficulties in performing activities of daily living and safe mobility. Stroke survivors usually have impaired walking characterized by decreased stance phase and prolonged swing phase of the paretic side, decreased walking speed and stride length. Weight shifting capacity is an important component in balance recovery and walking velocity. Weight shifting in the frontal plane onto the hemiparetic leg is reduced in individuals post-stroke, by as much as 25-43% of their body weight. These gait abnormalities place stroke survivors at a high risk of falls. Greater asymmetry of lower extremity power is strongly correlated with reduced walking velocity, stance time and swing time. Improving walking performance and safety is a major goal for stroke survivors and rehabilitation therapists in the early phases of rehabilitation to prevent falls and improve quality of life.Biofeedback (BFB) about performance is a powerful tool to aid individuals in understanding their deficits, for example in post-stroke the weakness of the impaired limb. Individuals receiving visual feedback about their weight shift during practice have demonstrated improvement in weight bearing and dynamic balance and gait activities. Providing biofeedback about limb weakness or reduced weight shift during walking is difficult in a rehabilitation setting, because of the need for expensive force plates and walking platforms.Cycling with BFB may be a viable and effective alternative.Cycling and walking have a similar kinematic pattern, with reciprocal flexion and extension of the hip, knee, and ankle and alternate activation of agonist/antagonists mucles. Exercising with BFB on a cycle ergometer has been shown to be feasible in individuals with chronic stroke and the cycling motion has demonstrated transfer of training to improved gait symmetry. We are proposing to collect preliminary data regarding the feasibility and effect of providing BFB of leg power using a recumbent cycle ergometer to improve gait speed and gait symmetry in individuals early after stroke, when rehabilitation typically occurs. Training individuals early post-stroke (post-acute care) using biofeedback on a cycle ergometer has not been assessed, to our knowledge.

Inclusion Criteria

Individuals will be included if: 

1) they have a confirmed MCA or ACA ischemic or intracerebral hemorrhagic stroke, confirmed by CT/MRI or clinical documentation AND demonstrating lower extremity hemiparesis (< 100 on lower limb Motricity Index; 2) 18 to 70 years of age; 3) a Functional Ambulation Category of 2 (Dependent Level II) through 5 (Independent Level surfaces only); and 4) medical clearance to participate.

Exclusion Criteria

Individuals will be excluded if they have: 1) contractures that limit lower limb range of motion; 2) cardiovascular, respiratory or metabolic instability, including unstable angina or hypertension above 200/110 at rest; 3) uncontrolled diabetes; 4) severe respiratory disorders that limit exercise; 5) inability to ambulate > 150 feet prior to stroke; 6) prior history of peripheral or central nervous system injury; 7) moderate to severe hemispatial neglect according to the Kessler Foundation Neglect Assessment;25 8) major cognitive impairment preventing the capability to understand training instructions; identified by inability to follow 3-step command; and 9) severe aphasia preventing communication with the therapist.