Acute Knee Crutch Use Provokes Changes to Postural Strategy

Abstract

Single-leg knee crutches are a relatively new, hands-free mobility assistive device with benefits over standard axillary crutches. Our main goal in this study was to evaluate balance ability in a healthy population upon first exposure to the knee crutch device. We had 20 healthy individuals (M age = 21.1; SD = 1.5 years) complete baseline static and dynamic balance tests on a force plate, followed by knee crutch fitting, a self-selected duration of ambulation practice, and another round of balance testing while wearing the knee crutch. We used the BTrackS Balance Test (BBT) to measure static balance, and the BTrackS Limits of Stability (BLOS) test to measure dynamic balance, and we created a custom lateral bias score from the BLOS results. On average, participants self-selected 3.1 minutes of ambulation practice. Wearing the knee crutch caused a near doubling of static balance path length and a large reduction in percentile ranking on the BBT. Dynamic balance area was more than halved (p < .001), with lateral bias scores during the BLOS, indicating that participants heavily favored their non-crutched leg (p < .001). Our results indicate that static and dynamic balance were significantly altered when wearing the knee crutch, and participants seemed to switch to a single leg stance strategy. Despite these balance changes, participants were quickly ready and willing to complete independent ambulation and balance testing procedures using the single-leg knee crutch.