It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements. How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane? Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed. In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC. The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.

Clinical experience tells us that the lower-limb amputees are one of the patient groups who clearly suffer from a strength deficit in their involved side. However, there is no obvious evidence for the relation between the residual limb strength and walking ability in this population. Correlating the results of the conventional clinical gait analysis (CGA) with strength tests could help to find out how deficits in strength impact the amputees' gait. In this contribution, a new device for measuring the isometric muscle strength of the hip and the knee was tested for feasibility. Three groups were tested: one group of 11 healthy subjects (29±5 years) to test the repeatability of the device, two unilateral amputees (one transfemoral for 56 years, one transtibial for 65 years), and a reference group of 17 healthy subjects (55±10 years). The new method presents an adequate technique to integrate strength testing within a standard protocol of the CGA. Results showed to be repeatable within sessions [i.e., within-day, intraclass correlation coefficient (ICC)>0.972] and between repeated measurements (i.e., day-to-day, ICC>0.765). The tested amputees showed clear deficits in maximum isometric joint moments in their most distal joint. The first results suggest evidence for a relation between the maximum isometric joint moments and gait deviations in amputees.