Energy cost, mechanical work and muscular efficiency in swing-through gait with elbow crutches.

Crutches are widely used to assist ambulation in disabled people. Many authors have shown that the use of crutches increases the energy cost as compared to normal walking. In this study we have measured the energy consumed and the mechanical work performed during swing-through crutch gait in order to assess if the greater energy expenditure is accompanied by an equivalent increase of the work done to move the body. Our results show that, depending upon the speed, the energy expenditure is 2-3 times higher in swing-through gait than in normal walking. On the other hand, the mechanical work increases only 1.3-1.5 times. Thus the extra cost of swing-through gait cannot be explained solely by an increase of the mechanical work, but is due at least in part to a reduction in the efficiency of positive work production.