Energy consumption during prosthetic walking and physical fitness in older hip disarticulation amputees.

The objective of this study is to investigate energy consumption during prosthetic walking and physical fitness in older hip disarticulation (HD) subjects and to examine the ambulatory outcome in a community setting. The subjects were seven unilateral HD amputees with an average age of 67.7 +/- 3.9 yr. Energy consumption was measured during prosthetic walking at each individual's comfortable walking speed (CWS) by means of a portable telemetric system. An incremental exercise test was performed to evaluate fitness. The average CWS for the subjects was 30.5 +/- 9.6 m/min. The average oxygen consumption rate at each CWS was 18.3 +/- 2.4 mL/kg/min, and the average oxygen cost was 0.639 +/- 0.165 mL/kg/m. The maximum oxygen uptake during exercise as a proportion of predicted maximum oxygen uptake (%VO2max) for the subjects was 57.2 +/- 11.1. Five subjects continued prosthetic walking on return to their communities. Two subjects abandoned prosthetic walking. The %VO2max for the five who continued prosthetic walking after discharge ranged from 55.8 to 72.0. The subjects who abandoned prosthetic walking had lower %VO2max of 43.3 and 44.2. Energy consumption during prosthetic walking at CWS seemed not to be excessive. Older HD amputees in good physical condition were able to successfully walk with a prosthesis in a community setting. A lower level of fitness appears to make community walking prohibitive.