Real-World Walking Performance of Individuals with Lower-Limb Amputation Classified as Medicare Functional Classification Level 2 and 3

Abstract

Introduction Lower-limb prostheses are prescribed based on each patient's individual needs. However, there is no standardized method to identify a patient's needs, which results in difficulty and variability in making prosthetic recommendations. Using measures of real-world walking performance in conjunction with clinical measures and the clinician's expertise may be an ideal way to ensure that patients receive the optimal prosthetic treatment. Currently, there is only limited understanding of the relationship among in-clinic performance-based measures, real-world walking performance, and K-level. Therefore, the purpose of this study was to investigate outcomes of in-clinic performance-based evaluations and real-world walking performance measures for individuals with unilateral lower-limb amputation classified as K2 and K3. Materials and Methods Twenty-seven individuals with unilateral lower-limb amputation classified as K2 or K3 functional levels underwent a clinical assessment visit that included a 10-m walk test and a 6-minute walk test. After the assessment, the individuals were equipped with an activity monitor, which they wore for a 7-day observation period. From these data, participants' self-selected walking speed, total distance walked in 6 minutes, total number of steps taken during the observation period, total number of active minutes during the observation period, and percentage of time spent in low-, moderate-, and high-intensity activity during the observation period were calculated. Results Individuals classified as K2 had, on average, a significantly slower self-selected walking speed, significantly shorter distance walked in 6 minutes, significantly lower total step count, and a significantly fewer number of active minutes when compared with those classified as K3. Although not significant, trends in activity intensity were seen with individuals classified as K2, spending a larger percentage of time in low-intensity activity and less percentage of time in high-intensity activity when compared with those classified as K3. Conclusions This study quantified real-world walking performance, in conjunction with in-clinic performance-based data, for individuals classified as K2 and K3 and showed significant differences between the 2 groups. This study is a step forward toward developing an objective and standardized method to classify an individual's functional ability and make prosthetic recommendations.