Exercise testing as a screening measure for ability to walk with aprosthesis after transfemoral amputation due to peripheral vascular disease.

Abstract

To establish at which exercise-power level is the vascular response, as measured by oxygen uptake, closest to the response during the 6-min walk test (6 MWT) in people after lower-limb amputation due to peripheral vascular disease (PVD). A prospective exploratory cohort study was conducted. 6 MWT and exercise testing using a hand-wheel ergometer (starting at 10 W and increasing the workload by 10 W) were performed in 101 consecutively recruited participants after transfemoral amputation due to PVD. Agreement of oxygen uptake during 6 MWT and exercise testing was compared between the groups defined by the exercise-power level reached. Linear regression through origin with Chow test for comparing slopes indicated that oxygen uptake at 30 W agreed more with 6 MWT than at 20, 40 or 50 W. Analyses of observed differences (one-way ANOVA with post-hoc tests, Jonckheere-Terpstra test) confirmed 30 W to be the recommendable threshold. At the level of 30 W, the oxygen uptake during the exercise was the closest to the 6 MWT, so we estimated that to be the minimum required level for walking using a prosthesis after transfemoral amputation due to PVD. Implications for Rehabilitation Exercise testing after transfemoral amputation. Walking with a prosthesis causes notable strain to the person's vascular system: after the 6-min walk test, the participants' heart rate reached 75% of the maximum predicted heart rate on average. The study shows that persons after transfemoral amputation due to peripheral vascular disease who reach the level of 30 W or more in exercise testing with an arm ergometer at admission to rehabilitation are likely to be able to walk in-doors using a prosthesis.