Comparative Study of Mobility and Perceived Exertion for the Wheeled Knee Walker and Axillary Crutches in Healthy Participants

Abstract

Category: Other Introduction/Purpose: Functional limitations are common after lower extremity surgery and often require the use of an assistive device for ambulation during rehabilitation and recovery. There is no known data evaluating the wheeled knee walker (WKW) as an assistive device for postoperative protected ambulation. The purpose of this study is to compare mobility and perceived exertion in the WKW and the axillary crutch (AC) in healthy volunteers. Methods: This is a cross sectional study of the WKW and the AC that was performed on 24 healthy volunteers utilizing the Six- Minute Walk Test (6MWT). The participants were randomized into two separate arms, one starting with the AC (N=12) and one starting with the WKW (N=12). A modified version of the American Thoracic Society (ATS) Guidelines for the 6MWT was performed for both assistive devices on all subjects. Pre-activity and post-activity heart rates were recorded for both events. From the 6MWT data the values for the Self Selected Walking Velocity (SSWV) were calculated and the subjects rating of perceived exertion was recorded using the OMNI Rating of Perceived Exertion (OMNI-RPE). Patient's preference for assistive device was identified. Results: The 6MWT, SSWV and the Omni-RPE were evaluated using paired T-tests and was determined to be statistically significant for the WKW when compared to the AC (p < 0.001). The confounding effect of the sequences were measured utilizing a mixed-model 2x2 ANOVA and was determined to have no significant 3 way (time x device x sequence) interaction (p = 0.968). Factorial 2 x 2 repeated measures ANOVA was used to evaluate the pre-activity and post-activity heart rates and demonstrated a statistically significant difference for the WKW when compared to the AC (p < 0.001). 87.5% of subjects preferred the WKW to the AC. Conclusion: The WKW provided increased mobility and had a lower rating of perceived exertion than the AC on level surfaces in healthy participants