scholarly journals Changes in muscle activity during the flexion and extension phases of arm cycling as an effect of power output are muscle-specific

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9759
Author(s):  
Carla P. Chaytor ◽  
Davis Forman ◽  
Jeannette Byrne ◽  
Angela Loucks-Atkinson ◽  
Kevin E. Power
Keyword(s):  
Neural Plasticity ◽  
Power Output ◽  
Muscle Activity ◽  
Neural Control ◽  
Peak Power Output ◽  
Emg Activity ◽  
Triceps Brachii ◽  
Arm Cycling ◽  
Extensor Carpi Radialis ◽  
Flexion And Extension

Arm cycling is commonly used in rehabilitation settings for individuals with motor impairments in an attempt to facilitate neural plasticity, potentially leading to enhanced motor function in the affected limb(s). Studies examining the neural control of arm cycling, however, typically cycle using a set cadence and power output. Given the importance of motor output intensity, typically represented by the amplitude of electromyographic (EMG) activity, on neural excitability, surprisingly little is known about how arm muscle activity is modulated using relative workloads. Thus, the objective of this study was to characterize arm muscle activity during arm cycling at different relative workloads. Participants (n = 11) first completed a 10-second maximal arm ergometry sprint to determine peak power output (PPO) followed by 11 randomized trials of 20-second arm cycling bouts ranging from 5–50% of PPO (5% increments) and a standard 25 W workload. All submaximal trials were completed at 60 rpm. Integrated EMG amplitude (iEMG) was assessed from the biceps brachii, brachioradialis, triceps brachii, flexor carpi radialis, extensor carpi radialis and anterior deltoid of the dominant arm. Arm cycling was separated into two phases, flexion and extension, relative to the elbow joint for all comparisons. As expected, iEMG amplitude increased during both phases of cycling for all muscles examined. With the exception of the triceps brachii and extensor carpi radialis, iEMG amplitudes differed between the flexion and extension phases. Finally, there was a linear relationship between iEMG amplitude and the %PPO for all muscles during both elbow flexion and extension.

scholarly journals Intensity matters: effects of cadence and power output on corticospinal excitability during arm cycling are phase and muscle dependent

2018 ◽  
Vol 120 (6) ◽  
pp. 2908-2921 ◽  
Author(s):  
E. J. Lockyer ◽  
R. J. Benson ◽  
A. P. Hynes ◽  
L. R. Alcock ◽  
A. J. Spence ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Power Output ◽  
Motor Evoked Potentials ◽  
Elbow Flexion ◽  
Corticospinal Excitability ◽  
Peak Power Output ◽  
Triceps Brachii ◽  
Arm Cycling ◽  
Power Outputs ◽  
Spinal Excitability

The present study investigated the effects of cadence and power output on corticospinal excitability to the biceps (BB) and triceps brachii (TB) during arm cycling. Supraspinal and spinal excitability were assessed using transcranial magnetic stimulation (TMS) of the motor cortex and transmastoid electrical stimulation (TMES) of the corticospinal tract, respectively. Motor-evoked potentials (MEPs) elicited by TMS and cervicomedullary motor-evoked potentials (CMEPs) elicited by TMES were recorded at two positions during arm cycling corresponding to mid-elbow flexion and mid-elbow extension (i.e., 6 and 12 o’clock made relative to a clock face, respectively). Arm cycling was performed at combinations of two cadences (60 and 90 rpm) at three relative power outputs (20, 40, and 60% peak power output). At the 6 o’clock position, BB MEPs increased ~11.5% as cadence increased and up to ~57.2% as power output increased ( P < 0.05). In the TB, MEPs increased ~15.2% with cadence ( P = 0.013) but were not affected by power output, while CMEPs increased with cadence (~16.3%) and power output (up to ~19.1%, P < 0.05). At the 12 o’clock position, BB MEPs increased ~26.8% as cadence increased and up to ~96.1% as power output increased ( P < 0.05), while CMEPs decreased ~29.7% with cadence ( P = 0.013) and did not change with power output ( P = 0.851). In contrast, TB MEPs were not different with cadence or power output, while CMEPs increased ~12.8% with cadence and up to ~23.1% with power output ( P < 0.05). These data suggest that the “type” of intensity differentially modulates supraspinal and spinal excitability in a manner that is phase- and muscle dependent. NEW & NOTEWORTHY There is currently little information available on how changes in locomotor intensity influence excitability within the corticospinal pathway. This study investigated the effects of arm cycling intensity (i.e., alterations in cadence and power output) on corticospinal excitability projecting to the biceps and triceps brachii during arm cycling. We demonstrate that corticospinal excitability is modulated differentially by cadence and power output and that these modulations are dependent on the phase and the muscle examined.

scholarly journals The Effects of Bench Press Variations in Competitive Athletes on Muscle Activity and Performance

2017 ◽  
Vol 57 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Atle Hole Saeterbakken ◽  
Dag-André Mo ◽  
Suzanne Scott ◽  
Vidar Andersen
Keyword(s):  
Muscle Activity ◽  
Latissimus Dorsi ◽  
Bench Press ◽  
Biceps Brachii ◽  
High Load ◽  
Emg Activity ◽  
International Level ◽  
Triceps Brachii ◽  
Competitive Athletes ◽  
And Performance

AbstractThe aim of the study was to compare the EMG activity performing 6RM competition style bench press (flat bench-wide grip) with 1) medium and narrow grip widths on a flat bench and 1) inclined and declined bench positions with a wide grip. Twelve bench press athletes competing at national and international level participated in the study. EMG activity was measured in the pectoralis major, anterior and posterior deltoid, biceps brachii, triceps brachii and latissimus dorsi. Non-significant differences in activation were observed between the three bench positions with the exception of 58.5-62.6% lower triceps brachii activation, but 48.3-68.7% greater biceps brachii activation in the inclined bench compared with the flat and declined bench position. Comparing the three grip widths, non-significant differences in activations were observed, with the exception of 25.9-30.5% lower EMG activity in the biceps brachii using a narrow grip, compared to the medium and wide grip conditions. The 6-RM loads were 5.8-11.1% greater using a medium and wide grip compared to narrow grip width and 18.5-21.5% lower in the inclined bench position compared with flat and declined. Comparing the EMG activity during the competition bench press style with either the inclined and declined bench position (wide grip) or using a narrow and medium grip (flat bench), only resulted in different EMG activity in the biceps- and triceps brachii. The 6RM loads varied with each bench press variation and we recommend the use of a wide grip on a flat bench during high load hypertrophy training to bench press athletes.

scholarly journals Spatiotemporal distribution of location and object effects in the electromyographic activity of upper extremity muscles during reach-to-grasp

2016 ◽  
Vol 115 (6) ◽  
pp. 3238-3248 ◽  
Author(s):  
Adam G. Rouse ◽  
Marc H. Schieber
Keyword(s):  
Upper Extremity ◽  
Muscle Activity ◽  
Neural Control ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Proximal Muscle ◽  
Reach To Grasp ◽  
Distal Muscle ◽  
The Subject ◽  
Later Phase

In reaching to grasp an object, proximal muscles that act on the shoulder and elbow classically have been viewed as transporting the hand to the intended location, while distal muscles that act on the fingers simultaneously shape the hand to grasp the object. Prior studies of electromyographic (EMG) activity in upper extremity muscles therefore have focused, by and large, either on proximal muscle activity during reaching to different locations or on distal muscle activity as the subject grasps various objects. Here, we examined the EMG activity of muscles from the shoulder to the hand, as monkeys reached and grasped in a task that dissociated location and object. We quantified the extent to which variation in the EMG activity of each muscle depended on location, on object, and on their interaction—all as a function of time. Although EMG variation depended on both location and object beginning early in the movement, an early phase of substantial location effects in muscles from proximal to distal was followed by a later phase in which object effects predominated throughout the extremity. Interaction effects remained relatively small. Our findings indicate that neural control of reach-to-grasp may occur largely in two sequential phases: the first, serving to project the entire upper extremity toward the intended location, and the second, acting predominantly to shape the entire extremity for grasping the object.

Effect of Arm Cranking Direction on EMG, Kinematic, and Oxygen Consumption Responses

2004 ◽  
Vol 20 (2) ◽  
pp. 129-143 ◽  
Author(s):  
Eadric Bressel ◽  
Gary D. Heise
Keyword(s):  
Oxygen Consumption ◽  
Muscle Activity ◽  
Biceps Brachii ◽  
Emg Activity ◽  
Half Cycle ◽  
Wrist Flexion ◽  
Triceps Brachii ◽  
Arm Cranking ◽  
Video Images ◽  
Consumption Data

The purpose of this study was to compare muscle activity, kinematic, and oxygen consumption characteristics between forward and reverse arm cranking. Twenty able-bodied men performed 5-min exercise bouts of forward and reverse arm cranking while electromyographic (EMG), kinematic, and oxygen consumption data were collected. EMG activity of biceps brachii, triceps brachii, deltoid, and infraspinatus muscles were recorded and analyzed to reflect on-time durations and amplitudes for each half-cycle (first 180° and second 180° of crank cycle). Kinematic data were quantified from digitization of video images, and oxygen consumption was calculated from expired gases. Dependent measures were analyzed with a MANOVA and follow-up univariate procedures; alpha was set at .01. The biceps brachii, deltoid, and infraspinatus muscles displayed greater on-time durations and amplitudes for select half-cycles of reverse arm cranking compared to forward arm cranking (p< 0.01). Peak wrist flexion was 9% less in reverse arm cranking (p< 0.01), and oxygen consumption values did not differ between conditions (p= 0.25). Although there were no differences in oxygen consumption and only minor differences kinematically, reverse arm cranking requires greater muscle activity from the biceps brachii, deltoid, and infraspinatus muscles. These results may allow clinicians to more effectively choose an arm cranking direction that either minimizes or maximizes upper extremity muscle activity depending on the treatment objectives.

scholarly journals Guidelines for Working Heights of the Lower-Limb Exoskeleton (CEX) Based on Ergonomic Evaluations

2021 ◽  
Vol 18 (10) ◽  
pp. 5199
Author(s):  
Yong-Ku Kong ◽  
Chae-Won Park ◽  
Min-Uk Cho ◽  
Seoung-Yeon Kim ◽  
Min-Jung Kim ◽  
...  
Keyword(s):  
Lower Limb ◽  
Muscle Activity ◽  
Biceps Brachii ◽  
Erector Spinae ◽  
Whole Body ◽  
Emg Activity ◽  
Triceps Brachii ◽  
Lower Limb Exoskeleton ◽  
Upper Trapezius ◽  
Subjective Discomfort

The aim of this study was to evaluate the muscle activities and subjective discomfort according to the heights of tasks and the lower-limb exoskeleton CEX (Chairless EXoskeleton), which is a chair-type passive exoskeleton. Twenty healthy subjects (thirteen males and seven females) participated in this experiment. The independent variables were wearing of the exoskeleton (w/ CEX, w/o CEX), working height (6 levels: 40, 60, 80, 100, 120, and 140 cm), and muscle type (8 levels: upper trapezius (UT), erector spinae (ES), middle deltoid (MD), triceps brachii (TB), biceps brachii (BB), biceps femoris (BF), rectus femoris (RF), and tibialis anterior (TA)). The dependent variables were EMG activity (% MVC) and subjective discomfort rating. When wearing the CEX, the UT, ES, RF, and TA showed lower muscle activities at low working heights (40–80 cm) than not wearing the CEX, whereas those muscles showed higher muscle activities at high working heights (100–140 cm). Use of the CEX had a positive effect on subjective discomfort rating at lower working heights. Generally, lower discomfort was reported at working heights below 100 cm when using the CEX. At working heights of 100–140 cm, the muscle activity when wearing the CEX tended to be greater than when not wearing it. Thus, considering the results of this study, the use of the lower-limb exoskeleton (CEX) at a working height of 40–100 cm might reduce the muscle activity and discomfort of whole body and decrease the risk of related disorders.

The Evaluations of the Muscle Activity During “Momi” by Using the Different Immersed Bamboo in Water to Making Kyo-Uchiwa (Japanese Paper Fan)

2013 ◽  
Author(s):  
Porakoch Sirisuwan ◽  
Chieko Narita ◽  
Tetsushi Koshino ◽  
Hisanori Yuminaga
Keyword(s):  
Muscle Activity ◽  
Latissimus Dorsi ◽  
Biceps Brachii ◽  
Gluteus Medius ◽  
Triceps Brachii ◽  
Flexor Carpi Radialis ◽  
Japanese Paper ◽  
Bending Process ◽  
The Difference ◽  
Extensor Carpi Radialis

The aim of study is to evaluate whether altering the bamboo moisture by immersed bamboo in water on 4-hour and 3 -day that would affect the muscle activity during separated bamboo by bending process. Moreover, thirteen muscles which bilateral side of Pectoralis major, Biceps brachii, Triceps brachii, Latissimus dorsi, Gluteus medius and only right side of Rectus abdominis, Extensor carpi radialis longus and Flexor carpi radialis were recorded. As a result, the bilateral side of Biceps brachii, right side of Extensor carpi radialis longus and Flexor carpi radialis, left side of Triceps brachii showed the difference quite clearly. When the craftsman was bending the bamboo he was necessary more effortful by these muscles activity on the 4-hour immersed bamboo in water than the 3-day. The scanning electron microscopy (SEM) photographs showed the fracture characteristic of 2 subjects that the adhesive of bamboo fiber decreased when increased moisture.

scholarly journals Corticospinal excitability to the biceps and triceps brachii during forward and backward arm cycling is direction- and phase-dependent

2020 ◽  
Vol 45 (1) ◽  
pp. 72-80
Author(s):  
Anna. P. Nippard ◽  
Evan. J. Lockyer ◽  
Duane. C. Button ◽  
Kevin. E. Power
Keyword(s):  
Evoked Potentials ◽  
Biceps Brachii ◽  
Motor Evoked Potentials ◽  
Elbow Flexion ◽  
Corticospinal Excitability ◽  
Extension Phase ◽  
Triceps Brachii ◽  
Arm Cycling ◽  
Spinal Excitability ◽  
Flexion And Extension

The purpose of this study was to evaluate corticospinal excitability to the biceps and triceps brachii during forward (FWD) and backward (BWD) arm cycling. Corticospinal and spinal excitability were assessed using transcranial magnetic stimulation and transmastoid electrical stimulation to elicit motor evoked potentials (MEPs) and cervicomedullary evoked potentials (CMEPs), respectively. MEPs and CMEPs were recorded from the biceps and triceps brachii during FWD and BWD arm cycling at 2 positions, 6 and 12 o’clock. The 6 o’clock position corresponded to mid-elbow flexion and extension during FWD and BWD cycling, respectively, while 12 o’clock corresponded to mid-elbow extension and flexion during FWD and BWD cycling, respectively. During the flexion phase, MEP and CMEP amplitudes of the biceps brachii were higher during FWD cycling. However, during the extension phase, MEP and CMEP amplitudes were higher during BWD cycling. For the triceps brachii, MEP amplitudes were higher during FWD cycling regardless of phase. However, CMEP amplitudes were phase-dependent. During the flexion phase, CMEPs of the triceps brachii were higher during FWD cycling compared with BWD, but during the extension phase CMEPs were higher during BWD cycling compared with FWD. The data suggest that corticospinal and spinal excitability to the biceps brachii is phase- and direction-dependent. In the triceps brachii, spinal, but not corticospinal, excitability is phase-dependent when comparing FWD and BWD cycling. Novelty This is the first study to assess corticospinal excitability during FWD and BWD locomotor output. Corticospinal excitability during arm cycling depends on the direction, phase, and muscle being assessed.

Sign in / Sign up

Export Citation Format

Share Document