Estimation of distal arm joint angles from EMG and shoulder orientation for transhumeral prostheses

Abstract

In this paper, we quantify the extent to which shoulder orientation, upper-arm electromyography (EMG), and forearm EMG are predictors of distal arm joint angles during reaching in eight subjects without disability as well as three subjects with a unilateral transhumeral amputation and targeted reinnervation. Prior studies have shown that shoulder orientation and upper-arm EMG, taken separately, are predictors of both elbow flexion/extension and forearm pronation/supination. We show that, for eight subjects without disability, shoulder orientation and upper-arm EMG together are a significantly better predictor of both elbow flexion/extension during unilateral (R2 = 0.72) and mirrored bilateral (R2 = 0.72) reaches and of forearm pronation/supination during unilateral (R2 = 0.77) and mirrored bilateral (R2 = 0.70) reaches. We also show that adding forearm EMG further improves the prediction of forearm pronation/supination during unilateral (R2 = 0.82) and mirrored bilateral (R2 = 0.75) reaches. In principle, these results provide the basis for choosing inputs for control of transhumeral prostheses, both by subjects with targeted motor reinnervation (when forearm EMG is available) and by subjects without target motor reinnervation (when forearm EMG is not available). In particular, we confirm that shoulder orientation and upper-arm EMG together best predict elbow flexion/extension (R2 = 0.72) for three subjects with unilateral transhumeral amputations and targeted motor reinnervation. However, shoulder orientation alone best predicts forearm pronation/supination (R2 = 0.88) for these subjects, a contradictory result that merits further study.

Neurorehabilitation in Adults With Traumatic Upper Extremity Amputation: A Scoping Review

“…Although there were few studies that discussed the use of professional rehabilitation training, the use of “training” or “practice” was mentioned in five out of the eleven studies. 19-21,23,24 Of those five studies, three included the use of a rehabilitation professional as described above. 19-21 The descriptions of the training or practice varied significantly between each study.…”

“…19-21 The descriptions of the training or practice varied significantly between each study. Akhtar et al 24 only mentioned the implementation of repetitive reaching testing trials including 48 reaches for participant practice for training and testing. Resnik et al 19 described the use of training participants to “generate appropriate muscle activation patterns,” stating one participant received seven hours of training on pattern recognition (PR) device use, while the other participant received 11 hours of training on direct control (DC) device use, and 12 hours of training on PR device use.…”

Shoulder kinematics plus contextual target information enable control of multiple distal joints of a simulated prosthetic arm and hand

“…Combining kinematics and myoelectric signals [ 14 , 33 ] could be used to integrate active grasp control to the present context-aware strategy. Most transradial prosthesis users are already familiar with myoelectric controls for hand opening and closing.…”

Towards Control of a Transhumeral Prosthesis with EEG Signals

“…An EMG signal is a measureable electric current from a muscle capable of providing control signals according to the user’s motion intention [ 1 ]. Recently, several studies [ 2 , 3 , 4 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ] have investigated EMG-based motion intention estimation techniques for prosthesis control. In [ 2 ], in order to control a transhumeral prosthesis, forearm and wrist motions were estimated using an artificial neural network (NN) based on shoulder and elbow motions, and hand motion was generated according to fuzzy rules.…”

“…Lenzi et al [ 4 ] proposed a 5-DoF transhumeral prosthesis for elbow, forearm, wrist, and grasping motions that used an EMG-based low-level controller. In [ 16 ], an NN-based method was proposed to estimate distal arm joint angles to control a transhumeral prosthesis using EMG and shoulder orientation. In addition, some studies [ 11 , 12 , 13 ] report EMG-based motion intention studies for much lower level amputation such as transradial or wrist disarticulation.…”