Effect on gait using various prosthetic ankle-foot devices.

Five different commonly prescribed ankle-foot devices for below-knee prostheses were tested for effects on gait: SACH, SAFE, SEATTLE, SINGLE AXIS, and MULTIPLE AXIS. Subjective ratings by the amputees served to resolve which physical variables determined the preferred ankle-foot device. Ratings were related to age, body weight, length of residual limb, and ratio of stride frequency to stride length.

Load-bearing characteristics of polyethylene foam: an examination of structural and compression properties.

Cellular foams used in shoe insoles come in a variety of structural configurations differing with respect to cell geometry. The compression of a cellular foam depends on cell reticulation and size. Examination of the compression behavior of closed cell polyethylene foams revealed distinct time-and nontime-related properties that occur during static and cyclic loading.

Effect of velocity and SF/SL ratio on external work and gait movement waveforms.

Ten normal adult subjects were tested under a wide range of combinations of stride length and stride frequency. Both longitudinal and vertical accelerations of the body increased with velocity, while stride frequency to stride length ratio (SF/SL) had little effect. The peak-to-peak amplitude of the forward velocity (V) decreased with SF/SL, but at constant SF/SL remained essentially unchanged throughout the speed range from 0.

Analysis of below-knee suspension systems: effect on gait.

Seven different suspension systems for below-knee prostheses were tested on 20 adult, unilateral amputees. All subjects walked with a prosthesis. Gait was evaluated with regard to longitudinal and vertical accelerations of the body, forward velocity, axial (piston) movement of amputated limb in the socket, and knee movement.

The role of non-invasive vascular studies in determining levels of amputation.

Various non-invasive vascular studies have been reported to provide valuable data for selection of the optimum level of amputation in limbs in patients who have vascular disease. We evaluated three such methods: (1) measurement of the change in the transcutaneous PO2 after inhalation of oxygen; (2) determination, by the Doppler method, of segmental blood pressure; and (3) measurement of the temperature of the skin. The records of eighty patients (ninety amputations) were retrospectively reviewed for correlations between the results of the vascular studies and the outcome of the amputation.