Experimental tests of a musculoskeletal model of the elbow joint for FES applications

Spasticity often interferes with function, limits independence and may cause considerable disability. Elbow joint movement is involved in many daily living activities. A surface EMG driven musculoskeletal model was developed to predict joint trajectory and to compare the differences in the model parameters between the normal and spastic subjects. Three musculotendon actuators whose EMG could be assessed by surface electrodes (biceps, brachioradialis and triceps) were included in this musculoskeletal model. The proposed model took several sets of parameters (anthropometric parameters of the skeleton and muscle parameters) as inputs. Surface EMG signals of the three muscle groups were rectified, moving-averaged, scaled and converted to active states. These active states together with the initial angular position and velocity of the joint were also used as inputs for the model. The outputs were muscle forces and the trajectory of the elbow joint. Two groups of parameters, namely, maximal isometric muscle stress and electromechanical delay were estimated using the trajectory fitting algorithm. Results indicated that the model was successful in using the surface EMG as input signals in the prediction of elbow joint trajectory. The spastic subjects showed a lower maximum isometric muscle stress and longer electromechanical delay.

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A novel method for elbow joint continuous prediction using EMG and musculoskeletal model

2013 IEEE International Conference on Robotics and Biomimetics (ROBIO) ◽

10.1109/robio.2013.6739634 ◽

2013 ◽

Cited By ~ 2

Author(s):

Muye Pang ◽

Shuxiang Guo

Keyword(s):

Elbow Joint ◽

Musculoskeletal Model ◽

Novel Method

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Development and Evaluation of a Musculoskeletal Model of the Elbow Joint Complex

Journal of Biomechanical Engineering ◽

10.1115/1.2795943 ◽

1996 ◽

Vol 118 (1) ◽

pp. 32-40 ◽

Cited By ~ 51

Author(s):

R. V. Gonzalez ◽

E. L. Hutchins ◽

R. E. Barr ◽

L. D. Abraham

Keyword(s):

Elbow Joint ◽

Muscle Force ◽

Elbow Flexion ◽

Musculoskeletal Model ◽

Joint Torque ◽

Time Varying ◽

Moment Arm ◽

Flexion Extension ◽

The Relationship ◽

Ballistic Movements

This paper describes the development and evaluation of a musculoskeletal model that represents human elbow flexion-extension and forearm pronation-supination. The length, velocity, and moment arm for each of the eight musculotendon actuators were based on skeletal anatomy and joint position. Musculotendon parameters were determined for each actuator and verified by comparing analytical moment-angle curves with experimental joint torque data. The parameters and skeletal geometry were also utilized in the musculoskeletal model for the analysis of ballistic (rapid-directed) elbow joint complex movements. The key objective was to develop a computational model, guided by parameterized optimal control, to investigate the relationship among patterns of muscle excitation, individual muscle forces, and to determine the effects of forearm and elbow position on the recruitment of individual muscles during a variety of ballistic movements. The model was partially verified using experimental kinematic, torque, and electromyographic data from volunteer subjects performing both isometric and ballistic elbow joint complex movements. This verification lends credibility to the time-varying muscle force predictions and the recruitment of muscles that contribute to both elbow flexion-extension and forearm pronation-supination.

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