Energy expenditure of transfemoral amputees during floor and treadmill walking with different speeds.

Background: Walking energy expenditure, calculated as the percent utilization of the maximal aerobic capacity, is little investigated in transfemoral amputees.

Objectives: Compare the energy expenditure of healthy participants (control participants) and transfemoral amputees walking with their respective preferred walking speeds on the treadmill (TPWS) and floor (FPWS).

Study Design: Randomized cross-over study.

Methods: Oxygen uptake (VO2) was measured when walking with the FPWS and TPWS. VO2max was measured by an incremental treadmill test.

Results: Mean ± standard deviation VO2max of the transfemoral amputees and control participants were 30.6 ± 8.7 and 49.0 ± 14.4 mL kg(-1) min(-1), respectively (p < 0.05). TPWS for the transfemoral amputees and control participants was 0.89 ± 0.2 and 1.33 ± 0.3 m s(-1), respectively (p < 0.01). FPWS for the transfemoral amputees and control participants was 1.22 ± 0.2 and 1.52 ± 0.1 m s(-1), respectively (p < 0.01). Walking on floor with the FPWS, the energy expenditure of the transfemoral amputees and control participants was 54% and 31% of VO2max, respectively (p < 0.01). Walking on the treadmill with the TPWS, the energy expenditure of the transfemoral amputees and control participants was 42% and 29% of the VO2max, respectively (p < 0.05).

Conclusion: Energy expenditure is higher for the transfemoral amputees than the control participants, regardless of walking surface. There are minimal differences in energy expenditure between treadmill and floor walking for the control participants but large differences for the transfemoral amputees.

Clinical Relevance: During walking, the transfemoral amputees expend a larger percentage of their maximal aerobic capacity than healthy participants. With a low VO2max, ordinary activities, such as walking, become physically more challenging for the transfemoral amputees than the control participants, and this may, in turn, have a negative effect on the walking range of the transfemoral amputees.