Modulation of Impedance and Muscle Activation of the Upper Limb Joints while Simultaneously Controlling Manual-grasping and Walking

The aim of this study was to compare the influence of constant or intermittent load on muscle activation and fatigue. The analysis and assessment of muscular activation and fatigue was based on surface EMG measurements from eight muscles (seven muscles of the right upper limb and trapezius muscle). Two EMG signal parameters were analyzed for each of the experimental conditions distinguished by the value of the external force and the character of the load – constant or intermittent. The amplitude related to its maximum (AMP) and the slope of the regression line between time and median frequency (SMF) were the EMG parameters that were analyzed. The results showed that constant load caused higher muscular fatigue than intermittent load despite the lower value of the external force and lower muscle activation. Results suggest that additional external force might influence muscle activation and fatigue more than upper limb posture. The results of the study support the thesis that all biomechanical factors which influence upper limb load and fatigue (upper limb posture, external force and time sequences) should be considered when work stands and work processes are designed. They also indicate that constant load should be especially avoided.

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Effect of Mirror Box Therapy on Muscle Activation Strategies after Upper Limb Amputation

Journal of Hand Therapy ◽

10.1016/j.jht.2017.11.020 ◽

2018 ◽

Vol 31 (1) ◽

pp. 154-155 ◽

Cited By ~ 2

Author(s):

L.F. Fernandes ◽

S.G. Shimano

Keyword(s):

Upper Limb ◽

Muscle Activation ◽

Limb Amputation ◽

Upper Limb Amputation ◽

Mirror Box

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Muscle Activation during Exergame Playing

Advances in Medical Technologies and Clinical Practice - Handbook of Research on Holistic Perspectives in Gamification for Clinical Practice ◽

10.4018/978-1-4666-9522-1.ch015 ◽

2016 ◽

pp. 312-341 ◽

Cited By ~ 1

Author(s):

Pooya Soltani ◽

João Paulo Vilas-Boas

Keyword(s):

Upper Limb ◽

Healthy Subjects ◽

Muscle Activation ◽

Low Cost ◽

Coding System ◽

User Research ◽

Preliminary Results ◽

Upper Trapezius ◽

Game Developers ◽

Muscular Coordination

Exergames may provide low-cost solutions for playing, training and rehabilitation. Exergame user research, studies the interaction between an exergame and users, in order to provide feedback for game developers and safe and meaningful game play. Detailed evaluations and a coding system based on muscle activation levels are necessary to characterize. This is important when it comes to use exergames in purposes other than fun. The purpose of this chapter was to characterize the muscle activation during a swimming exergame and to compare the level of activation during different conditions. Healthy subjects played bouts of exergame using Xbox360 and Kinect. Muscle activation was monitored for desired muscles on dominant upper limb using wireless electromyography system. An investigation of muscular coordination was also conducted to provide activation sequences of studied muscles. Preliminary results showed that upper trapezius was the most active muscle in all techniques. Results can provide insights for practitioners to have a baseline on application of exergames in their routines.

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Selectivity and excitability of upper-limb muscle activation during cervical transcutaneous spinal cord stimulation in humans

Journal of Applied Physiology ◽

10.1152/japplphysiol.00132.2021 ◽

2021 ◽

Author(s):

Roberto M. de Freitas ◽

Atsushi Sasaki ◽

Dimitry G. Sayenko ◽

Yohei Masugi ◽

Taishin Nomura ◽

...

Keyword(s):

Spinal Cord ◽

Upper Limb ◽

Spinal Cord Stimulation ◽

Muscle Activation ◽

Anterior Neck ◽

Hand Muscles ◽

Ia Afferents ◽

Arm Muscles ◽

Muscle Responses ◽

Transcutaneous Spinal Cord Stimulation

Cervical transcutaneous spinal cord stimulation (tSCS) efficacy for rehabilitation of upper-limb motor function was suggested to depend on recruitment of Ia afferents. However, selectivity and excitability of motor activation with different electrode configurations remains unclear. In this study, activation of upper-limb motor pools was examined with different cathode and anode configurations during cervical tSCS in 10 able-bodied individuals. Muscle responses were measured from six upper-limb muscles simultaneously. First, post-activation depression was confirmed with tSCS paired pulses (50 ms interval) for each cathode configuration (C6, C7, and T1 vertebral levels), with anode on the anterior neck. Selectivity and excitability of activation of the upper-limb motor pools were examined by comparing the recruitment curves (10-100 mA) of first evoked responses across muscles and cathode configurations. Our results showed that hand muscles were preferentially activated when the cathode was placed over T1 compared to the other vertebral levels, while there was no selectivity for proximal arm muscles. Furthermore, higher stimulation intensities were required to activate distal hand muscles than proximal arm muscles, suggesting different excitability thresholds between muscles. In a separate protocol, responses were compared between anode configurations (anterior neck, shoulders, iliac crests, and back), with one selected cathode configuration. The level of discomfort was also assessed. Largest muscle responses were elicited with the anode configuration over the anterior neck, while there were no differences in the discomfort. Our results therefore inform methodological considerations for electrode configuration to help optimize recruitment of Ia afferents during cervical tSCS.

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Upper Limb Muscle Activation: An EMG Analysis Using Myo® Armband

XXVI Brazilian Congress on Biomedical Engineering - IFMBE Proceedings ◽

10.1007/978-981-13-2119-1_61 ◽

2019 ◽

pp. 397-404

Author(s):

Gabriela Alves Maia de Souza ◽

Marilú Gomes Netto Monte da Silva ◽

Alana Elza Fontes da Gama

Keyword(s):

Upper Limb ◽

Muscle Activation ◽

Limb Muscle

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Muscle Activation Levels During Upper Limb Exercise Performed Using Dumbbells and A Spring-Loaded Exoskeleton

Journal of Medical and Biological Engineering ◽

10.1007/s40846-017-0226-4 ◽

2017 ◽

Vol 37 (3) ◽

pp. 345-356 ◽

Cited By ~ 1

Author(s):

Tzong-Ming Wu ◽

Chih-Han Yang ◽

Dar-Zen Chen

Keyword(s):

Upper Limb ◽

Muscle Activation ◽

Limb Exercise

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Cathodal transcranial direct current stimulation of the primary motor cortex improves selective muscle activation in the ipsilateral arm

Journal of Neurophysiology ◽

10.1152/jn.00171.2011 ◽

2011 ◽

Vol 105 (6) ◽

pp. 2937-2942 ◽

Cited By ~ 30

Author(s):

Alana B. McCambridge ◽

Lynley V. Bradnam ◽

Cathy M. Stinear ◽

Winston D. Byblow

Keyword(s):

Motor Cortex ◽

Upper Limb ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Muscle Activation ◽

Primary Motor Cortex ◽

Selectivity Ratio ◽

Direct Current Stimulation ◽

Antagonist Muscles ◽

Stimulation Of

Proximal upper limb muscles are represented bilaterally in primary motor cortex. Goal-directed upper limb movement requires precise control of proximal and distal agonist and antagonist muscles. Failure to suppress antagonist muscles can lead to abnormal movement patterns, such as those commonly experienced in the proximal upper limb after stroke. We examined whether noninvasive brain stimulation of primary motor cortex could be used to improve selective control of the ipsilateral proximal upper limb. Thirteen healthy participants performed isometric left elbow flexion by contracting biceps brachii (BB; agonist) and left forearm pronation (BB antagonist) before and after 20 min of cathodal transcranial direct current stimulation (c-tDCS) or sham tDCS of left M1. During the tasks, motor evoked potentials (MEPs) in left BB were acquired using single-pulse transcranial magnetic stimulation of right M1 150–270 ms before muscle contraction. As expected, left BB MEPs were facilitated before flexion and suppressed before pronation. After c-tDCS, left BB MEP amplitudes were reduced compared with sham stimulation, before pronation but not flexion, indicating that c-tDCS enhanced selective muscle activation of the ipsilateral BB in a task-specific manner. The potential for c-tDCS to improve BB antagonist control correlated with BB MEP amplitude for pronation relative to flexion, expressed as a selectivity ratio. This is the first demonstration that selective muscle activation in the proximal upper limb can be improved after c-tDCS of ipsilateral M1 and that the benefits of c-tDCS for selective muscle activation may be most effective in cases where activation strategies are already suboptimal. These findings may have relevance for the use of tDCS in rehabilitation after stroke.

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PATTERNS AND CONSISTENCY OF MUSCLE RECRUITMENT FOR A KARATE JAB

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237211002396 ◽

2011 ◽

Vol 23 (01) ◽

pp. 75-82 ◽

Cited By ~ 1

Author(s):

Yu-Lin Ning ◽

Jia-Da Li ◽

Wei-Ching Lo ◽

Chih-Hung Huang ◽

Chu-Fen Chang ◽

...

Keyword(s):

Upper Limb ◽

Muscle Activation ◽

Biceps Brachii ◽

Erector Spinae ◽

Lower Limbs ◽

Medial Gastrocnemius ◽

Muscle Recruitment ◽

Triceps Brachii ◽

Motor Time ◽

Karate Athletes

Adequate pattern and consistency of the muscle recruitment is essential to symbolize the destruction of the opponent with high movement velocities and precise targeting of the opponent's head and body during a karate jab. The purpose of this study was to evaluate the reaction time (RT), motor time (MT), and total response time (TRT), as well as their correlation during a karate jab, and to investigate the recruitment pattern and consistency of muscles during motor time. As many as 14 professional karate athletes (age: 23.67 ± 2.64 years; height: 174.57 ± 7.13 cm; and weight: 72.75 ± 10.65 kg) participated in the current study. Each subject was instructed to pose in combat stance first and then to use their left hand to jab at an instrumented kicking target as soon as they saw the start signal. Surface electromyograms (EMGs) were recorded from 16 muscles, namely the pronator teres, biceps brachii, triceps brachii, and deltoid of the left upper limb, right erector spinae, left rectus abdominis, and gluteus maximus, rectus femoris, biceps femoris, tibialis anterior, and medial gastrocnemius of the right and left lower limbs. Start and stop signals from the instrumented target were also recorded synchronously to obtain the TRT. Significant correlation between MT and TRT indicated that MT was a key determinant for the TRT of the jab. When performing a karate jab, the karate athletes initiated the movement with postural adjustments of the legs and trunk prior to the onset of the voluntary jab by the upper limb, and with a proximal-to-distal sequence of muscle activation in the left arm. Good consistencies of muscle recruitment of the trunk, left arm, and leg, and cocontraction of the left triceps and biceps brachii also indicated a well-controlled jab by the left arm. These results provide important information on the patterns and the consistencies of the muscle recruitment for coaching a karate jab, which should be helpful for a better understanding of the motor control strategies of a karate jab and for developing a suitable training protocol.

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