Dynamics and Muscle Forces Estimation of Human Lower Limb Based on a Sit-to-stand Training Robot
Human lower limb is a complex musculoskeletal system, and direct measurement of tensile force of muscles locate at the inner part of limbs is not convenient in the present medical situation.For supporting the medical diagnoses in rehabilitation activities, a new quantitative method for estimating dynamics and muscle forces of human lower limb is presented based on a developed sit-tostand training robot and AnyBody Modeling System.The sit-to-stand training robot adopts a double-ropes control method to offer assistance in the rehabilitation activities, meanwhile in the robot system the rotational motions of body segments could be measured by wearable motion sensors, and tri-axial ground reaction force (GRF) and center of pressure (COP) could be measured by a miniature type force plate.The AnyBody Modeling System professionally concerns on musculoskeletal kinematic modeling and analysis, a minimum fatigue criterion way is employed to assure that the human body would maximize its endurance and precisely, and quantitative results of muscle forces could be calculated through an inverse dynamics method in the system.In this study a musculoskeletal model composed of thigh, shank, foot, four rotational joints, and fifteen muscles was established in the AnyBody Modeling System and the geometry information of the model with magnification coefficient were determined from the anatomy datum of human lower limb.Then test experiments were implemented and four volunteers were requested to stand up from a chair in selfselected speed, and the dynamics parameters of body segments were real-time measured by the sensors in the training robot.At last the measured dynamics data were applied on the musculoskeletal model, and the quantitative muscle forces of lower limb were calculated out through the inverse dynamics method.Furthermore for validating the muscle force results, the qualitative muscle activation level was also measured in the test experiments by electromyography (EMG) method, and the measured EMG results showed a considerable comparability with the calculated AnyBody results.The dynamics and muscle forces results also showed that the rehabilitation training robot could improve conditions of lower limb muscles effectively, the sensors could give a great performance in measuring motions and GRF, and variation tendency of the muscle force results have fact significance in the sit-tostand process.Therefore, the method for estimating muscle forces appears to be a practical means to determine dynamics parameters in musculoskeletal analysis of human limb, and the system may be applied as a convenient instrument in clinical settings.
Enguo Cao Yoshio Inoue Kyoko Shibata Tao Liu
Department of Intelligent Mechanical SystemsEngineeringKochi University of Technology185 Miyanokuchi Department of Intelligent MechanicalSystems EngineeringKochi University of Technology185 Miyanokuchi Department of Intelligent Mechanical Systems Engineering Kochi University of Technology 185 Miyanoku
国际会议
上海
英文
1-8
2012-08-26（万方平台首次上网日期，不代表论文的发表时间）