Gait Inefficiency in Trans Femoral Amputation

The length of the residual stump and the abduction range are correlated to the gait inefficiencies seen with transfemoral amputation. Both of these observations are explicable on a biomechanical basis. A short thigh stump will not allow effective transmission of limb acceleration in preswing by the hip flexors and a limitation of abduction range will not allow circumduction as a clearance mechanism.

The larger the prosthesis the greater the inertial forces generated by the limb. Gitter showed that transfemoral amputees have the ability to use the mass of the limb to conserve energy thus substantially negating the handicap of a heavier limb sufficient to compensate for the increased inertial forces.

Whatever the prosthesis the energy inefficiency of bilateral transfemoral amputations is such that only the fitest are able to walk usefully (Crouse, 1990). Transfemoral amputees walk more slowly than their most efficient gait speed and at their most comfortable speed have a similar cost in terms of extra heart beats per minute compared with normals walking at self selective speed.

Patients with hip disarticulations have higher energy consumptions than those with transfemoral amputation with oxygen consumption 80% - 125% higher than normals

References

Boonstra AM, Schrama J, Fidler V, Eisma WH. The gait of unilateral transfemoral amputees. Scand J Rehabil Med !1994;26(4):217-23.

Crouse SF, Lessard CS, Rhodes J, Lowe RC. Oxygen consumption and cardiac response of short-leg and long-leg prosthetic ambulation in a patient with bilateral above-knee amputation: comparisons with able-bodied men. Arch Phys Med Rehabil 1990;71(5):313-7.

Gitter A, Czerniecki J, Meinders M. Effect of prosthetic mass on swing phase work during above-knee amputee ambulation. Am J Phys Med Rehabil 1997;76(2):114-21.

Nowroozi F, Salvanelli ML, Gerber LH. Energy expenditure in hip disarticulation and hemipelvectomy amputees. Arch Phys Med Rehabil 1983;64(7):300-3.

Speed vs Efficiency:

Jaegers SM, Vos LD, Rispens P, Hof AL. The relationship between comfortable and most metabolically efficient walking speed in persons with unilateral above-knee amputation. Arch Phys Med Rehabil 1993;74(5):521-5.