Impairment Variables Predicting Activity Limitation in Individuals with Lower Limb Amputation

Abstract

The purpose of this study was to determine whether measures of impairment (i.e., muscle strength, balance), personal factors (i.e., comorbidities, demographic information) and amputation specific variables (i.e., time since amputation, cause of amputation, level of amputation) were able to predict performance on the six-minute walk test, a measure of activity limitation, in individuals with lower limb amputation. A total of 72 individuals with lower limb amputation ranging in age from 21-83 were tested for balance, limb muscle strength and function. Medical comorbidities were recorded and activity limitation was measured using the six-minute walk test. Data were analyzed and multivariate relationships were examined using multiple linear regression. Impairment variables of strength, balance, subject demographics, time since amputation, cause of amputation and level of amputation were all significant predictors and explained 72% of the variance in the outcome variable. Strength of the hip extensors was the strongest predictor, accounting for 30.9% of the total variance. Multiple factors impact six minute walk scores in individuals with lower limb amputation. Impairments in hip strength and balance appear to be the two most significant. The findings of this study support the use of the six-minute walk test to underscore impairments of the musculoskeletal system that can affect ambulation ability in the amputee.

Application of self-report and performance-based outcome measures to determine functional differences between four categories of prosthetic feet

“…The non-PVD group was faster than the PVD group but not statistically significant. However, both groups were within the moderate range (61-79 m/min) [31] at baseline. The non-PVD group, when wearing the Talux and Proprio feet, increased their velocities to what is considered moderate to fast walking velocities (80-96 m/min) [46], resulting in a significant difference between groups with the Proprio foot (p < 0.05).…”

“…Because both groups were considered within normal ranges for nondisabled adults [31] and instructed according to the American Thoracic Society Guideline for the 6MWT to cover as much distance as possible in 6 min, we did not anticipate that a change of foot would significantly increase their self-selected walking speed. All groups had a mean 6MWT distance that was consistent with or slightly higher than previous reports [13].…”

“…The 6MWT has been found to be effective in determining functional capacity using peak oxygen uptake [27][28]; predicting community ambulation capacity [29]; and assessing overall performance, mobility, and cardiovascular fitness [30]. More recently, contributing variables such as hip extensor strength, age, single-limb balance time, and symmetry of step length have been found to correlate with 6MWT performance in people with amputation [31]. The 6MWT distance has been shown to be responsive to functional training interventions in people with lower-limb amputation [29].…”

Influence of physical capacities of males with transtibial amputation on gait adjustments on sloped surfaces

“…A functional score out of 70 was calculated from the PPA-LCI, and a score out of 30 was calculated from the mobility item of the SF-36. The functional capacities of subjects with amputation were tested with the 6MWT, measuring the distance covered in 6 min by the patients on level surface [2].…”

“…For example, muscular capacities of the patients are evaluated by quantifying maximal isometric muscular strengths [1]. Functional evaluations are also used to give global scores based on self-reported questionnaires such as the Prosthetic Profile Amputee-Locomotor Capacities Index (PPA-LCI) and the 36-Item Short Form Health Survey (SF-36) or on performance measures such as the 6-minute walk test (6MWT) [2]. Finally, quantitative analysis of gait provides detailed biomechanical parameters useful to the understanding of gait limitations [3].…”