Objective Hemipelvectomy amputation is a surgical procedure in which the lower limb and a portion of pelvic are removed. There are a few studies on the performance of this group of patients while walking. The aim of this paper was to evaluate the effect of hemipelvectomy amputation on kinematics and muscle force generation of the lower limb while walking with Canadian prosthesis.
Materials & Methods A subject who underwent hemipelvectomy amputation on his left side and whose mass, height, and age were 75 kg, 1.75 m, and 39 years, respectively, was involved in this study. Qualisys motion analysis system with seven cameras and force-plate system were used to record marker tracking and ground reaction forces. Twenty reflective markers were attached to the subject’s body. As the subject walked , the data was recorded. The mean of five trials was used for statistical computing. The data was collected with the frequency of 120 Hz and filtered with 10 Hz low-pass filter. Muscloskeletal modeling was conducted by Visual 3D and OpenSim software. All data were analyzed using the SPSS 19 software at α=0.05.
Results There were significant differences between knee and ankle joint kinematic pattern at Loading, Mid-stance, Terminal stance, and Pre-swing phases of gait (P<0.05). 
In weight acceptance phase and mid-stance phase, ankle plantar flexion and dorsi-flexion range of motion, respectively, were significantly lower in the patient compared to a healthy subject (P=0.00). At the end of the stance phase, ankle range of motion was significantly different in the patient compared to the healthy subject (P=0.00). In the pre-swing phase, ankle plantar flexion was 11.5 degrees greater than that of the healthy subject. In mid-swing phase, patients showed more ankle dorsi-flexion compared to the healthy subject. In weight acceptance phase, knee flexion of patient (P=0.00) was significantly greater than that of the healthy subject, and in mid-stance phase, knee extension of patient was significantly greater (P=0.04). In pre-swing phase (P=0.00) and initial swing (P=0.02), there were significant differences between knee flexion of patients and healthy subjects. The pattern of hip range of motion during gait cycle was the same for the patient and the healthy subject (P>0.05). Force generation of the hip abductor, hip extensor, and knee extensor along with tibialis anterior and posterior of the patients in the sound leg were significantly more than that of the normal subject (P<0.05).
Conclusion The kinematics pattern of the patient’s lower limb during gait is different. Kinematic changes are associated with a significant increase in lower limb muscle generation that can have a degenerative effect on the knee joint. So the importance of this subject should be considered by rehabilitation experts.