Comparison of Ground Reaction Forces Components on Sound and Prosthetic Legs in Trans-Tibial Amputated Individuals

Aims: The utilization of prosthesis not only changes the gait pattern in the patients with lower-limb amputations, but also applies asymmetrical forces on the limbs leading to disturbances. Therefore, it is very important to identify the application mode of earth’s reaction forces on the lower limbs in walking. The aim of this study was to analyze the components of earth’s reaction forces in healthy leg and prosthetic leg in the patients with unilateral below the knee amputation.
In the observatory cross-sectional study, 10 patients with unilateral below the knee amputation of rehabilitation clinics of Isfahan were studied in 2013. The subjects were selected via non-probable available sampling method. Qualisys motion analysis system was used to record different gait phases. Kistler force plate was used to measure the earth’s reaction forces. Data was analyzed by SPSS 22 software using independent T test.
Findings: In the prosthetic leg, the propulsion impulse (p=0.01) and vertical impulse (p=0.05) of the reaction force of the earth and the loading rate (p=0.03) were lower than the healthy leg by 5.82N/s, 63.25N/s, and 12.8N/s, respectively. Time to peak reaction force of the earth on the prosthetic side was more than the healthy side by 4.9s (p=0.05).There was no significant difference between prosthetic and healthy legs in braking impulse, medio-lateral impulse, peak of braking force, peak of propulsion force, and unloading rate (p>0.05).
Greater propulsive impulse, vertical impulse, and loading on the healthy leg than the prosthetic leg in the patients with unilateral below the knee amputation shows that there is a greater loading time interval on the healthy leg.