High Velocity Quadriceps Exercises Compared to Slow Velocity Quadriceps Exercises Following Total Knee Arthroplasty

Background: Despite improvement in pain and perceived function in patients who have undergone total knee arthroplasty (TKA), objective outcome measures of muscular impairment and ambulatory function demonstrate significant deficits compared to the univolved side and to age-matched healthy adults. Some evidence suggests that quadriceps power may play a greater role in ambulatory function than measures of strength following TKA. Objective: The purpose of this sudy was to compare the effect of high velocity (HV) to slow velocity (SV) quadriceps exercises on functional outcomes and quadriceps power following knee arthroplasty. Design: This study used a double-blinded randomized controlled clinical trial design and was conducted in a university hospital outpatient physical therapy clinic in patients who underwent TKA. Methods: Nineteen patients between the ages of 50 and 85 years old and four to six weeks out from unilateral TKA were randomly assigned to a HV group or SV group. Subjects performed an evidence-bsed standard progressive exercise program in addition to either HV quadriceps exercises or SV quadriceps exercises. Subjects attended two sessions per week for eight weeks. Before and after the eight-week exercise intervention, subjects completed a functional questionnaire, health survey, functional testing, and underwent quadriceps strength and power testing. Results: Both groups demonstrated improvement in ambulatory outcome measures, strength, speed and power. The HV group demonstrated significantly greater improvement in distance walked and perceived physical function, compared to the SV group. Limitations: Limited subject numbers may be responsible for a Type I error. There was no control for the amount of exercise workload between groups. The eight-week intervention may not have been sufficient to maximize differences. Conclusion: HV quadriceps exercises are an effective rehabilitation strategy in conjunction with a standardized progressive resistance exercise program beginning four to six weeks after total knee arthroplasty.