Improving Function After Knee Arthroplasty With Weight-Bearing Biofeedback (RELOAD)

This study has been completed.
Information provided by (Responsible Party):
University of Colorado, Denver Identifier:
First received: April 8, 2011
Last updated: December 10, 2013
Last verified: December 2013

People who have had knee replacement surgery typically have worse physical function, compared to healthy people of similar age. This problem occurs despite completion of standard rehabilitation programs. One reason for less than optimal restoration of physical function is standard rehabilitation does not effectively address habitual movement patterns that persist after surgery. These movement patterns are characterized by patients placing less weight on their surgical leg compared to their non-surgical leg after surgery. This asymmetrical movement pattern has been identified by researchers and shown to not completely resolve after knee replacement surgery, even though the surgery reliably reduces knee pain. The persistence of asymmetrical weight-bearing during every day activity may limit the stimulus needed for full recovery by the muscles and joints of the surgical leg. By promoting increased loading of the surgical leg, a greater stimulus can be provided to promote better functional recovery, compared with standard rehabilitation. As a result, people may subsequently move more symmetrically with improved recovery of physical function. Improved function would in turn promote the person's ability to participate in life events, limiting disability. Considering that over 500,000 knee replacement surgeries occur in the United States each year, maximizing functional recovery and limiting disability following surgery are important goals.

The investigators propose a new method of exercising following knee replacement surgery. This method involves using a commercially available game system to promote "re-loading" of the surgical limb. The game system has games designed to allow the person playing to move objects or characters on a screen by shifting his/her weight from one leg to another while standing on an instrumented "balance board". The investigators have developed an exercise program to promote shifting weight to the surgical limb, by choosing appropriate games and manipulating the goals of those games. It is the investigators hypothesis that early application of this surgical leg "re-loading" intervention after knee replacement will result in meaningful improvement in physical function by improving movement symmetry.

Condition Intervention Phase
Arthropathy of Knee Joint
Other: Weight-bearing biofeedback exercise
Other: Standard of care exercise
Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Single Blind (Subject)
Primary Purpose: Treatment
Official Title: Improving Function After Knee Arthroplasty With Weight-Bearing Biofeedback

Resource links provided by NLM:

Further study details as provided by University of Colorado, Denver:

Primary Outcome Measures:
  • Weight-bearing symmetry [ Time Frame: 6 weeks post-operative ] [ Designated as safety issue: No ]
    Weight-bearing symmetry is measured during transitions between sitting and standing and compared to the control group as indicated by greater symmetry in vertical ground reaction force (vGRF) between lower limbs.

Secondary Outcome Measures:
  • Five Times Sit-to-Stand Test [ Time Frame: 6 weeks post-operative ] [ Designated as safety issue: No ]
    The Five Times Sit-to-Stand Test will be quantified as the total time required for an individual to rise from and return to a chair five times in a row.

  • Six-minute Walk Test [ Time Frame: 6 weeks post-operative ] [ Designated as safety issue: No ]
    The Six-minute Walk Test will assess gait function on level surfaces and is a standardized measure of the total distance walked over 6 minutes.

  • Stair Climb Test [ Time Frame: 6 weeks post-operative ] [ Designated as safety issue: No ]
    The Stair Climb Test will be used to assess gait function on stairs and is a standardized measure of the time to ascend and descend a flight of stairs.

Enrollment: 26
Study Start Date: January 2011
Study Completion Date: December 2012
Primary Completion Date: December 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Weight-bearing biofeedback exercise Other: Weight-bearing biofeedback exercise

Patients in the experimental group will complete the same standard of care rehabilitation program as the control group. Thus, the experimental intervention will be in addition to the standard intervention.

Upon discharge to home, patients in the RELOAD group will begin the weight bearing (WB) biofeedback phase of the study. Patients will participate in two 30-minute training sessions/week with a physical therapist for a total of 6 weeks, focusing on promoting WB symmetry using a progressive series of activities adapted to video games.

Active Comparator: Standard of care exercise Other: Standard of care exercise
Standard inpatient rehabilitation will begin on post-operative day 1 and last for an estimated 3 days. After hospital discharge, two weeks of home rehabilitation (6 visits) will be provided by physical therapists. Patients will progress to outpatient rehabilitation, consisting of 4 weeks of treatment. As such, 6 weeks of rehabilitation following hospital discharge will be implemented for both groups.


Ages Eligible for Study:   50 Years to 85 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • unilateral total knee arthroplasty, body mass index <35 kg/m2

Exclusion Criteria:

  • neurological, vascular or cardiac problems that limit physical function, severe osteoarthritis or other orthopaedic conditions in the non-operated lower extremity that limit function, sub-acute inpatient rehabilitation following unilateral total knee arthroplasty
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Please refer to this study by its identifier: NCT01333189

United States, Colorado
University of Colorado
Aurora, Colorado, United States, 80045
Sponsors and Collaborators
University of Colorado, Denver
Principal Investigator: Cory L Christiansen, PT, PhD University of Colorado, Denver
  More Information

No publications provided

Responsible Party: University of Colorado, Denver Identifier: NCT01333189     History of Changes
Other Study ID Numbers: 10-1185, 2558404
Study First Received: April 8, 2011
Last Updated: December 10, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by University of Colorado, Denver:
total knee arthroplasty
gait processed this record on August 27, 2015