We compared and evaluated the unloading effect and the availability of four different types of lower limb casts.

The subjects were ten healthy men who had no gait disturbances, neuromuscular disorder, and deformities of lower extremities. The mean age was 25.2years(22-29) and the mean weight was 62.6kg(53.9-69.1). The trials consisted of patellar tendon bearing(PTB) casts, short leg casts, long leg extension casts, and long leg 30° flexion casts. In each experiment, ten sets of measurements were taken with all subjects wearing four different types of lower limb casts and walking on a flat surface indoors. The load cell was placed on the sole of the foot and wrapped with casts so that we could measure the pressure of the sole during gait. The percentage of load reduction was calculated by comparing pressure of the soles and the bottom of the casts.

The unloading effects of the PTB, the short leg, the long leg extension, and the long leg 30° flexion casts were 23.8%, 19.5%, 25.5%, 27.9% of the loading. No significant difference of unloading effect was demonstrated between each four different types of lower limb casts(P>0.05).

Notwithstanding the clinical success of the lower limb casts in below knee fractures, the unloading effect of the casts was limited and any type of the casts did not show better unloading effects.