Predicting EMG Based Elbow Joint Torque Model Using Multiple Input ANN Neurons for Arm Rehabilitation

2014 ◽  
Author(s):  
Mohd Hafiz Jali ◽  
Tarmizi Ahmad Izzuddin ◽  
Zul Hasrizal Bohari ◽  
Mohamad Fani Sulaima ◽  
Hafez Sarkawi
Keyword(s):  
Elbow Joint ◽  
Joint Torque ◽  
Arm Rehabilitation ◽  
Multiple Input

Surface EMG signals based elbow joint torque prediction

2013 ◽  
Author(s):  
W. D. I. G. Dasanayake ◽  
R. A. R. C. Gopura ◽  
V. P. C. Dassanayake ◽  
G. K. I. Mann
Keyword(s):  
Elbow Joint ◽  
Surface Emg ◽  
Joint Torque

Dynamic Electromyographic Models to Assess Elbow Joint Torque

2013 ◽  
Vol 461 ◽  
pp. 608-617
Author(s):  
Wan Zhong Chen ◽  
Yue Yu Fan ◽  
Jun Lei ◽  
Bao Feng Sun
Keyword(s):  
Linear Model ◽  
Elbow Joint ◽  
Dynamic Models ◽  
Surface Emg ◽  
Feature Model ◽  
Joint Torque ◽  
Zero Crossing ◽  
Emg Amplitude ◽  
Single Feature ◽  
Rms Error

Many studies have investigated the relationship between surface EMG and joint torque. Most studies have used EMG amplitude to assess elbow joint torque with dynamic models. In this paper, we used signal length and normalized zero crossing rates together with EMG amplitude to assess elbow joint torque with EMG-to-Torque models. We compared the performance of single feature EMG-to-Torque models and multi-feature EMG-to-Torque models by calculating the RMS error between estimated torque and true torque. The results show that multi-channel and multiple feature combination is superior to that of the single feature only. In this study, surface EMG signals were recorded from biceps and triceps muscles of 15 subjects. Single-channel and single feature linear model, multi-channel and single-feature model, multi-channel and single-feature model, multi-channel and multi-feature linear model were all used to assess elbow joint torque. The lowest RMS error is 7.6% achieved by four-channel multi-feature 18-order linear model.

Neural compensation for muscular fatigue: evidence for significant force regulation in man

1987 ◽  
Vol 57 (6) ◽  
pp. 1893-1910 ◽  
Author(s):  
R. F. Kirsch ◽  
W. Z. Rymer
Keyword(s):  
Elbow Joint ◽  
Time Course ◽  
Statistical Significance ◽  
Joint Torque ◽  
Single Type ◽  
Time Averaging ◽  
Loop Gain ◽  
Emg Signal ◽  
Before And After ◽  
Neural Compensation

We have investigated the role of reflex regulation of muscle force in normal human subjects by comparing changes in the stretch-evoked increments in elbow joint flexor electromyogram (EMG) and elbow joint torque before and after fatigue. Elbow flexor muscle fatigue was induced by repetitive voluntary isometric contractions. To assess the appropriateness of the EMG signal as an index of neural excitation of muscle under fatiguing conditions, we examined the time course of recovery of joint torque and EMG power spectrum following fatigue. Fatigue-related changes in the EMG power spectra recovered within 5–10 min after fatiguing exercise was terminated, yet the muscle weakness induced by the exercise lasted greater than 7 h and was substantial in magnitude. The decoupling of torque and EMG recovery allowed us to compare pre- and postfatigue EMG stretch responses without adjusting for differences in EMG spectral content. Torque and EMG responses to stretch were quantified by time-averaging over 250-ms “isometric” and “steady-state” periods, just before and just after a ramp angular stretch of the elbow joint, respectively. The torque increment elicited by stretch was lower following fatigue in seven of eight experiments. However, the average decrease of 20.13 +/- 14.42% in these seven subjects was somewhat smaller than the corresponding average shift in the slope of the isometric EMG-torque relationship of 85.84 +/- 90.29% (n = 8). Furthermore, the stretch-induced EMG increment was larger following fatigue in all eight sessions (average of 56.14 +/- 28.96%, n = 8), with six of the shifts reaching statistical significance for alpha = 0.05. Because the pattern of torque and EMG responses before and after fatigue suggested the presence of an active force regulator, we used a simple model of the neuromuscular system to estimate a loop gain value for each session. When pre- and postfatigue responses were matched by isometric background torque level, an average loop gain value of 7.9 was computed, whereas for responses matched by average prestretch EMG level, the loop gain estimates averaged 2.1. Although our assessment of force regulation was essentially static and derived from the responses to a single type of perturbation, the change in the incremental torque and EMG stretch responses indicates that meaningful neural compensation for fatigue occurred. Moreover, the loop gain estimates derived from these responses are an order of magnitude larger than those previously reported in animal models, suggesting that force regulation may be important in the control of human muscle contraction.

scholarly journals The Effect of Ulnar Collateral Ligament Repair With Internal Brace Augmentation on Articular Contact Mechanics: A Cadaveric Study

2021 ◽  
Vol 9 (4) ◽  
pp. 232596712110010
Author(s):  
Travis S. Roth ◽  
David P. Beason ◽  
T. Bradley Clay ◽  
E. Lyle Cain ◽  
Jeffrey R. Dugas
Keyword(s):  
Contact Mechanics ◽  
Elbow Joint ◽  
Angular Displacement ◽  
Ulnar Collateral Ligament ◽  
Biomechanical Properties ◽  
Joint Torque ◽  
Return To Play ◽  
Ligament Repair ◽  
Collateral Ligament ◽  
Intact State

Background: There has been renewed interest in ulnar collateral ligament (UCL) repair in throwing athletes because of a greater understanding of UCL injuries, improvement in ligament repair technology, and potentially expedited rehabilitation time and return to play relative to UCL reconstruction. Purpose: To evaluate elbow articular contact and overall joint torque after UCL reconstruction and repair augmented with a collagen-coated fiber tape, InternalBrace. Study Design: Controlled laboratory study. Methods: Ten matched pairs of cadaveric arms (mean age, 41 ± 11 years) were dissected to expose the UCL. Each specimen was secured into a custom test fixture at 90°, and 1 specimen from each pair underwent either a modified Jobe UCL reconstruction or UCL repair with InternalBrace. Each specimen underwent 10 cycles of elbow valgus angular displacement between 0° and 5° at a rate of 1 deg/s in the intact state, after UCL avulsion, and then after UCL reconstruction or repair. Articular contact mechanics and overall joint torque and stiffness were recorded. Results: Contact mechanics of reconstructed and repaired specimens were not significantly different. Both reconstruction and repair procedures returned the overall resistance of the joint to valgus torsion to near-intact levels. UCL repair tended to restore joint torque more closely to the intact state than did reconstruction, given that reconstruction showed a nonsignificant trend toward lower torque than the intact state ( P = .07). Conclusion: Neither UCL reconstruction nor UCL repair with InternalBrace overconstrained the elbow joint, as both groups had similar contact pressures compared with the native joint. Both procedures also restored elbow joint torque and stiffness to levels not statistically different from the intact state. Clinical Relevance: Given the sound biomechanical properties of UCL repair with InternalBrace, it may have a significant role as treatment for UCL injuries.

scholarly journals Just noticeable differences for elbow joint torque feedback

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hubert Kim ◽  
Alan T. Asbeck
Keyword(s):  
Elbow Joint ◽  
Spatial Information ◽  
Dynamic Condition ◽  
Pressure Sensors ◽  
Static Condition ◽  
Joint Torque ◽  
Just Noticeable Difference ◽  
Joint Torques ◽  
Static Conditions ◽  
Joint Torque Feedback

AbstractJoint torque feedback is a new and promising means of kinesthetic feedback imposed by a wearable device. The torque feedback provides the wearer temporal and spatial information during a motion task. Nevertheless, little research has been conducted on quantifying the psychophysical parameters of how well humans can perceive external torques under various joint conditions. This study aims to investigate the just noticeable difference (JND) perceptual ability of the elbow joint to joint torques. The paper focuses on the ability of two primary joint proprioceptors, the Golgi-tendon organ (GTO) and muscle spindle (MS), to detect elbow torques, since touch and pressure sensors were masked. We studied 14 subjects while the arm was isometrically contracted (static condition) and was moving at a constant speed (dynamic condition). In total there were 10 joint conditions investigated, which varied the direction of the arm’s movement and the preload direction as well as torque direction. The JND torques under static conditions ranged from 0.097 Nm with no preload to 0.197 Nm with a preload of 1.28 Nm. The maximum dynamic JND torques were 0.799 Nm and 0.428 Nm, when the arm was flexing and extending at 213 degrees per second, respectively.

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