Antigravity treadmill training during the early rehabilitation phase following unicompartmental knee arthroplasty: A case series

ABSTRACT

Patients who have undergone unicompartmental knee arthroplasty (UKA) have been reported to exhibit altered gait 19–25 months post-surgery. The most common gait impairment in this population is inadequate knee flexion and a corresponding decrease in the knee extensor moment during loading response (i.e., quadriceps avoidance). The purpose of this case series was to determine whether incorporation of antigravity treadmill training into a standard physical therapy program can eliminate quadriceps avoidance gait during the early rehabilitation phase following UKA. Four females who underwent UKA were recruited for this study. Participants completed antigravity treadmill training three times per week for 12 weeks in addition to their standard physical therapy program. Instrumented gait analysis was performed at baseline (pre-intervention), week 6 (mid-intervention), and week 12 (post-intervention). We found that peak knee flexion and the peak knee extensor moment during the weight acceptance phase of gait increased to normal values following the 12-week intervention period (14.1 ± 6.5° to 20.6 ± 1.5° and 0.4 ± 0.3 to 0.7 ± 0.2 Nm/kg respectively). The findings of this case series suggest that a standard physical therapy program that incorporates early gait training using an antigravity treadmill may be beneficial in eliminating “quadriceps avoidance” during the early rehabilitation phase following UKA.

KEYWORDS:

• Antigravity treadmill
• rehabilitation
• knee arthroplasty

Acknowledgments

The authors thank Jeri Ward R.N for her assistance with participant recruitment. They also thank Jesus Dominguez PhD, PT, and Alberto Vallejo, PhD, for their help in this case series.

Declaration of interest

Dr Christopher Powers is on the Alter-G Board of Advisors.