The Validation of Musculoskeletal Model During Isokinetic Exercise at Knee Joint: An Experimental and Simulation Study / 대한정형외과연구학회지

PURPOSE: This study validated the musculoskeletal model of the human lower extremity by comparative study between calculated muscle parameters through simulation using modified hill-type model and measured muscle parameters through isokinetic exercise. The relationship between muscle forces and moments participated in motion was quantified from the results of simulation. MATERIALS AND METHODS: For simulation of isokinetic motion, a three-dimensional anatomical knee model was constructed using gait analysis. The EMG-force model was used to determine muscle activation level exciting muscles. The modified Hill-type model was used to calculate individual muscle force and moment in dynamic analysis. This method was validated by comparing analytical data with experimental data. RESULTS: The results showed that there was a significant correlation between calculated torques from simulation and measured torque from isokinetic motion experiments (R=0.97). We also found that muscle forces and moments during knee flexion and extension have nonlinearly proportional or inversely proportional relationship, since lower extremity muscles were simultaneously involved in flexion/extension motion and inner/outer rotation. CONCLUSION: We concluded that the simulation by using musculoskeletal model may be a useful mean to predict and recover musculoskeletal-related diseases, and analyze complicated experiment such as clash condition.

A Study on the Effect of Degree of Freedom of Ankle Motion on Gait of Transfemoral Amputees with SNS Control Prosthesis / 대한정형외과연구학회지

Using three different types of the ankle joint, i.e., the fixed, single-axis, and multi axis type, the gait characteristics of transfemoral amputees were investigated to understand the biomechanics of ankle joint motion during gait of transfemoral amputees with a SNS (swing and stance phase) control prosthesis controlling the flexion-extension of knee in the stance phase unlike conventional swing control prostheses. The socket pressure was measured to explain the resulting gait characteristic of the transfemoral amputees for different ankle joint components. Based on the results from the gait characteristics, socket pressure, knee flexion-extension behavior, and ground reaction vector, the fixed type ankle joint could be considered as the most appropriate ankle joint for the transfemoral amputees using the SNS control prosthesis.

A Study on the Effect of Degree of Freedom of Ankle Motion on Gait of Transfemoral Amputees with SNS Control Prosthesis / 대한정형외과연구학회지

Using three different types of the ankle joint, i.e., the fixed, single-axis, and multi axis type, the gait characteristics of transfemoral amputees were investigated to understand the biomechanics of ankle joint motion during gait of transfemoral amputees with a SNS (swing and stance phase) control prosthesis controlling the flexion-extension of knee in the stance phase unlike conventional swing control prostheses. The socket pressure was measured to explain the resulting gait characteristic of the transfemoral amputees for different ankle joint components. Based on the results from the gait characteristics, socket pressure, knee flexion-extension behavior, and ground reaction vector, the fixed type ankle joint could be considered as the most appropriate ankle joint for the transfemoral amputees using the SNS control prosthesis.