DefinePK

Abstract

A human ankle supplies a great amount of net positive energy during the walking stance period, mostly for intermediate to fast walking speeds. Instead of that, the commercially available ankle-foot- prosthesis are totally passive during stance, consequently can’t provide the net positive work then the clinical examinations to patients who suffered from transtibial amputation using the conventional prosthesis presented high rate of metabolic energy as compared to normal people. Researchers approved that the main cause of high metabolism is due to inability of the conventional prosthesis providing net positive work at the terminal stance in walking. Therefore, a design of exoskeleton used for the patients who suffer from below knee amputations is proposed. The main aim of this study is evaluating the hypothesis of powered device in the ankle-foot prosthesis that can provide a positive energy at the terminal stance and can improve the patient metabolic walking economy, compared with patient using the conventional prosthesis. The proposed quasi-passive exoskeleton is consisted from controllable actuator and linearspring to simulate the human ankle-foot behavior. The exoskeleton device is constructed. The activity of exoskeleton is tested by patient has ankle foot prosthesis. The metabolism of the patients is also tested by measuring the electromyography (EMG) for patient muscles as well before and after wearing the device. The initial device tests showed an enhancement in electromyography (EMG) over 27% as compared to passive prosthesis, although the device weighed 1.18 KG, these results support the hypothesis and suggest a further work promise to improve the prosthesis. Also Conservation of the natural movement kinematics was described as an important requirement for a device to be beneficial in term of metabolic energy.