INVESTIGATING THE EFFECTS OF PASSIVE MECHANICAL ANKLE ON UNILATERAL OSTEOMYOPLASTIC TRANSTIBIAL AMPUTEES

Abstract

Purpose The study presents an investigation of the asymmetries in normal gait associated with the use of prosthetic mechanical passive ankle devices when performing ambulatory-related activities for unilateral osteomyoplastic transtibial amputees. Asymmetries in gait may lead to low-back pain and other long-term effects associated with hip compensation and excessive energy consumption. Methods Unilateral transtibial osteomyoplastic amputees were tasked to perform normal gait. The Vicon Motion system and Myomotion System consisting of electromyography sensors and inertial measurement units were used to collect data. Quantitative gait analysis was used for the analysis of anatomical angles for the ankle, knee, hip and pelvis. The results were compared to normative data. Result It was hypothesized that the unilateral amputees would demonstrate high peaks on the hip, knee and ankle of the intact side so as to compensate for the lack of propulsive force on the passive ankle of the prosthetic limb. All parameters for anatomical angles were found to be significant ([Formula: see text]), hip flexion ([Formula: see text]), knee flexion ([Formula: see text]) and ankle dorsiflexion ([Formula: see text]). Temporal and distance variables were quantitatively analyzed and there was no significant difference. Poor management of range of motion was observed on the ankle and the knee. There was minimum hip extension during the stance phase. There was excessive hip rotation and foot plantarflexion on the intact side of the amputee as hip compensation was being applied during the toe-off period and early swing. Amputees exhibited short stance time duration. Conclusion This study demonstrated that amputees can achieve same distance variables as normal subjects; however, this causes variations in anatomical angles which result in asymmetries in normal gait. Variations in lateral pelvic tilt indicated possible development of lower back pain and changes in posture.