PATTERNS AND CONSISTENCY OF MUSCLE RECRUITMENT FOR A KARATE JAB

2011 ◽  
Vol 23 (01) ◽  
pp. 75-82 ◽  
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.

scholarly journals Investigating the Effects of Mental Fatigue on Resistance Exercise Performance

2021 ◽  
Vol 18 (13) ◽  
pp. 6794
Author(s):  
Denver M. Y. Brown ◽  
Amanda Farias Zuniga ◽  
Daanish M. Mulla ◽  
Divya Mendonca ◽  
Peter J. Keir ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Perceived Exertion ◽  
Biceps Brachii ◽  
Experimental Manipulation ◽  
Mental Fatigue ◽  
Erector Spinae ◽  
Future Research ◽  
Dynamic Resistance ◽  
Triceps Brachii ◽  
Upper Trapezius

Mental fatigue can impart negative effects on subsequent physical performance, although the mechanisms underlying these effects are not well understood. This study examined whether mental fatigue confers negative carryover effects on the performance of a set of biceps curls, while also investigating physiological and psychological mechanisms proposed to explain the predicted effect. A randomized, cross-over design was employed. On visit 1, participants (N = 10) performed a barbell biceps curl one-repetition maximum (1RM) test. On visits 2–3, participants performed 20 biceps curls at 50% of their 1RM, followed by their respective 10 min experimental manipulation (high vs. low cognitive exertion) and then a second set of biceps curls to exhaustion. Ratings of perceived exertion and electromyography of the biceps brachii, triceps brachii, upper trapezius, thoracic erector spinae and lumbar erector spinae were recorded during the physical task. The total number of repetitions completed was similar across the conditions. Results also failed to show between-condition differences for muscle activation and perceptions of exertion. Future research is needed to build an adequate knowledge base to determine whether there is an effect of mental fatigue on dynamic resistance-based task performance and, if so, identify the mechanisms explaining how and why.

scholarly journals Selective Activation of Shoulder, Trunk, and Arm Muscles: A Comparative Analysis of Different Push-Up Variants

2015 ◽  
Vol 50 (11) ◽  
pp. 1126-1132 ◽  
Author(s):  
Giuseppe Marcolin ◽  
Nicola Petrone ◽  
Tatiana Moro ◽  
Giuseppe Battaglia ◽  
Antonino Bianco ◽  
...  
Keyword(s):  
Upper Limb ◽  
Muscle Activation ◽  
Pectoralis Major ◽  
Erector Spinae ◽  
Spine Injury ◽  
Emg Activity ◽  
Triceps Brachii ◽  
Back Muscles ◽  
Narrow Base ◽  
Push Up

Context The push-up is a widely used exercise for upper limb strengthening that can be performed with many variants. A comprehensive analysis of muscle activation during the ascendant phase (AP) and descendant phase (DP) in different variants could be useful for trainers and rehabilitators. Objective To obtain information on the effect of different push-up variants on the electromyography (EMG) of a large sample of upper limb muscles and to investigate the role of the trunk and abdomen muscles during the AP and DP. Design Cross-sectional study. Setting University laboratory. Patients or Other Participants Eight healthy, young volunteers without a history of upper extremity or spine injury. Intervention(s) Participants performed a set of 10 repetitions for each push-up variant: standard, wide, narrow, forward (FP), and backward (BP). Surface EMG of 12 selected muscles and kinematics data were synchronously recorded to describe the AP and DP. Main Outcome Measure(s) Mean EMG activity of the following muscles was analyzed: serratus anterior, deltoideus anterior, erector spinae, latissimus dorsi, rectus abdominis, triceps brachii caput longus, triceps brachii caput lateralis, obliquus externus abdominis, pectoralis major sternal head, pectoralis major clavicular head, trapezius transversalis, and biceps brachii. Results The triceps brachii and pectoralis major exhibited greater activation during the narrow-base variant. The highest activation of abdomen and back muscles was recorded for the FP and BP variants. The DP demonstrated the least electrical activity across all muscles, with less marked differences for the abdominal and erector spinae muscles because of their role as stabilizers. Conclusions Based on these findings, we suggest the narrow-base variant to emphasize triceps and pectoralis activity and the BP variant for total upper body strength conditioning. The FP and BP variants should be implemented carefully in participants with low back pain because of the greater activation of abdominal and back muscles.

scholarly journals Investigating the effects of mental fatigue on resistance exercise performance

2021 ◽  
Author(s):  
Denver M. Y. Brown ◽  
Amanda Farias Zuniga ◽  
Daanish Mulla ◽  
Divya Mendonca ◽  
Peter Keir ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Perceived Exertion ◽  
Biceps Brachii ◽  
Experimental Manipulation ◽  
Mental Fatigue ◽  
Erector Spinae ◽  
Future Research ◽  
Dynamic Resistance ◽  
Triceps Brachii ◽  
Upper Trapezius

Mental fatigue can impart negative effects on subsequent physical performance, although the mechanisms underlying these effects are not well understood. This study examined whether mental fatigue confers negative carryover effects on the performance of a set of biceps curls, while also investigating physiological and psychological mechanisms proposed to explain the predicted effect. A randomized, cross-over design was employed. On Visit 1, participants (N = 10) performed a barbell biceps curl one-repetition maximum (1RM) test. On Visits 2/3, participants performed 20 biceps curls at 50% of their 1RM, followed by their respective 10-minute experimental manipulation (high vs. low cognitive exertion), and then a second set of biceps curls to exhaustion. Ratings of perceived exertion and electromyography of the biceps brachii, triceps brachii, upper trapezius, thoracic erector spinae, and lumbar erector spinae were recorded during the physical task. The total number of repetitions completed was similar across the conditions. Results also failed to show between-condition differences for muscle activation and perceptions of exertion. Future research is needed to build an adequate knowledge base to determine whether there is an effect of mental fatigue on dynamic resistance-based task performance, and if so, identifying the mechanisms explaining how and why.

scholarly journals Effects of Dominant and Nondominant Limb Immobilization on Muscle Activation and Physical Demand during Ambulation with Axillary Crutches

2021 ◽  
Vol 6 (1) ◽  
pp. 16
Author(s):  
Kara B. Bellenfant ◽  
Gracie L. Robbins ◽  
Rebecca R. Rogers ◽  
Thomas J. Kopec ◽  
Christopher G. Ballmann
Keyword(s):  
Lower Limb ◽  
Muscle Activation ◽  
Weight Bearing ◽  
Lower Limbs ◽  
Medial Gastrocnemius ◽  
Bipedal Walking ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Physical Demand ◽  
Limb Dominance

The purpose of this study was to investigate the effects of how limb dominance and joint immobilization alter markers of physical demand and muscle activation during ambulation with axillary crutches. In a crossover, counterbalanced study design, physically active females completed ambulation trials with three conditions: (1) bipedal walking (BW), (2) axillary crutch ambulation with their dominant limb (DOM), and (3) axillary crutch ambulation with their nondominant limb (NDOM). During the axillary crutch ambulation conditions, the non-weight-bearing knee joint was immobilized at a 30-degree flexion angle with a postoperative knee stabilizer. For each trial/condition, participants ambulated at 0.6, 0.8, and 1.0 mph for five minutes at each speed. Heart rate (HR) and rate of perceived exertion (RPE) were monitored throughout. Surface electromyography (sEMG) was used to record muscle activation of the medial gastrocnemius (MG), soleus (SOL), and tibialis anterior (TA) unilaterally on the weight-bearing limb. Biceps brachii (BB) and triceps brachii (TB) sEMG were measured bilaterally. sEMG signals for each immobilization condition were normalized to corresponding values for BW.HR (p < 0.001) and RPE (p < 0.001) were significantly higher for both the DOM and NDOM conditions compared to BW but no differences existed between the DOM and NDOM conditions (p > 0.05). No differences in lower limb muscle activation were noted for any muscles between the DOM and NDOM conditions (p > 0.05). Regardless of condition, BB activation ipsilateral to the ambulating limb was significantly lower during 0.6 mph (p = 0.005) and 0.8 mph (p = 0.016) compared to the same speeds for BB on the contralateral side. Contralateral TB activation was significantly higher during 0.6 mph compared to 0.8 mph (p = 0.009) and 1.0 mph (p = 0.029) irrespective of condition. In conclusion, limb dominance appears to not alter lower limb muscle activation and walking intensity while using axillary crutches. However, upper limb muscle activation was asymmetrical during axillary crutch use and largely dependent on speed. These results suggest that functional asymmetry may exist in upper limbs but not lower limbs during assistive device supported ambulation.

Heteronymous reflex connections in human upper limb muscles in response to stretch of forearm muscles

2011 ◽  
Vol 106 (3) ◽  
pp. 1489-1499 ◽  
Author(s):  
Curtis D. Manning ◽  
Parveen Bawa
Keyword(s):  
Upper Limb ◽  
Biceps Brachii ◽  
Monosynaptic Reflex ◽  
Electromyographic Activity ◽  
Response Patterns ◽  
Triceps Brachii ◽  
Limb Muscles ◽  
Abductor Digiti Minimi ◽  
Human Upper Limb ◽  
Wrist Flexors

Torque motor produced stretch of upper limb muscles results in two distinct reflex peaks in the electromyographic activity. Whereas the short-latency reflex (SLR) response is mediated largely by the spinal monosynaptic reflex pathway, the longer-latency reflex (LLR) is suggested to involve a transcortical loop. For the SLRs, patterns of heteronymous monosynaptic Ia connections have been well-studied for a large number of muscles in the cat and in humans. For LLRs, information is available for perturbations to proximal joints, although the protocols for most of these studies did not focus on heteronymous connections. The main objective of the present study was to elicit both SLRs and LLRs in wrist flexors and extensors and to examine heteronymous connections from these muscles to elbow flexors (biceps brachii; BiBr) and extensors (triceps brachii; TriBr) and to selected distal muscles, including abductor pollicis longus (APL), first dorsal interosseous (FDI), abductor digiti minimi (ADM), and Thenars. The stretch of wrist flexors produced SLR and LLR peaks in APL, FDI, ADM, Thenars, and BiBr while simultaneously inducing inhibition of wrist extensors and TriBr. When wrist extensors were stretched, SLR and LLR peaks were observed in TriBr, whereas the primary wrist flexors, APL and BiBr, were inhibited; response patterns of FDI, ADM, and Thenars were less consistent. The main conclusions from the observed data are that: 1) as in the cat, afferents from wrist flexors and extensors make heteronymous connections with proximal and distal upper limb muscles; and 2) the strength of heteronymous connections is greater for LLRs than SLRs in the distal muscles, whereas the opposite is true for the proximal muscles. In the majority of observations, SLR and LLR excitatory peaks were observed together. However, on occasion, LLRs were observed without the SLR response in hand muscles when wrist extensors were stretched.

scholarly journals The Role of Motor Learning on Measures of Physical Requirements and Motor Variability During Repetitive Screwing

2019 ◽  
Vol 16 (7) ◽  
pp. 1231 ◽  
Author(s):  
Tessy Luger ◽  
Robert Seibt ◽  
Monika Rieger ◽  
Benjamin Steinhilber
Keyword(s):  
Muscle Activation ◽  
Biceps Brachii ◽  
Extensor Digitorum ◽  
Body Parts ◽  
Triceps Brachii ◽  
Experimental Conditions ◽  
Motor Variability ◽  
Physical Requirement ◽  
Flexor Carpi Radialis ◽  
Arm Muscles

We investigated whether physical requirements and motor variability decreased over days in novices during a repetitive screwing task. Fifty-seven subjects performed one hour of repetitive screwing and fastening on three days, separated by 2–7 days. The average physical requirement and relative cycle-to-cycle variability (coefficient of variation, i.e., CV) were calculated from continuous recordings of electromyography of four arm muscles (biceps brachii, triceps brachii, flexor carpi radialis, extensor digitorum), forearm acceleration, and electrocardiography. Muscle activity levels, heart rate, and forearm acceleration decreased from day 1 to day 2 (range: ~4% to ~20%) and/or 3 (range: ~4% to ~28%). Not all muscles showed a similar pattern. Activity of the extensor digitorum and biceps brachii decreased already between days 1 and 2 (range: ~6% to ~13%), whereas activity of the flexor carpi radialis and triceps brachii decreased between days 1 and 3 (range: ~13% to ~20%). No changes in physical requirement were detected between days 2 and 3. Relative motor variability did not change across days, except that variability of forearm acceleration increased from day 1 to 3 (~5%). This study found consistent changes in physical requirements and indicated that several arm muscles show earlier decreases of muscular activity, like the extensor digitorum, compared to other body parts, like the flexor carpi radialis. Moreover, movement strategies may develop differently than muscle activation strategies, based on the different developments of physical requirements and motor variability. The development of physical requirements in industrial tasks is part of daily living and starts at task onset, highlighting the importance of task familiarization and the randomization of experimental conditions in scientific studies.

A validated approach for collecting fine-wire electromyographic recordings in four canine shoulder muscles during highly dynamic tasks

2015 ◽  
Vol 11 (2) ◽  
pp. 65-74 ◽  
Author(s):  
K.L. Cullen ◽  
J.P. Dickey ◽  
S.H.M. Brown ◽  
S.G. Nykamp ◽  
L.R. Bent ◽  
...  
Keyword(s):  
Data Collection ◽  
Muscle Activation ◽  
Biceps Brachii ◽  
Electrode Placement ◽  
Electromyographic Activity ◽  
Anatomical Landmarks ◽  
Triceps Brachii ◽  
Performance Tasks ◽  
Fine Wire ◽  
Shoulder Muscles

This study investigated the feasibility of obtaining ultrasound-guided intramuscular fine-wire electromyographic (fEMG) recordings from four canine shoulder muscles during highly dynamic activities. Four cadaveric canines were utilised to confirm the appropriate anatomical landmarks and the use of real time ultrasound guidance for electrode placement for four shoulder muscles: Biceps Brachii (BB), Supraspinatus (SP), Infraspinatus (IF), and Triceps Brachii – Long Head (TBLH). Electromyographic activity of the left BB, S P, IF, and TBLH was then recorded in two research dogs while walking and trotting to refine the data collection procedures. Finally, the full experimental protocol was piloted with two client-owned, specially-trained agility dogs, confirming the feasibility of collecting fEMG recordings while performing dynamic, highly-specific agility-related tasks and verifying our EMG amplitude normalisation protocol to enable comparisons across muscles and performance tasks. We present specific guidelines regarding the placement of fEMG electrodes and data collection/normalisation procedures to enable investigations of muscle activation during dynamic activities.

Kinematics, Kinetics, and Muscle Activation during Explosive Upper Body Movements

1996 ◽  
Vol 12 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Robert U. Newton ◽  
William J. Kraemer ◽  
Keijo Häkkinen ◽  
Brendan J. Humphries ◽  
Aron J. Murphy
Keyword(s):  
Muscle Activation ◽  
Biceps Brachii ◽  
Average Power ◽  
Upper Body ◽  
Emg Activity ◽  
Neural Activation ◽  
Loading Conditions ◽  
Force Output ◽  
Triceps Brachii ◽  
Average Force

The aim of this study was to investigate the kinematics, kinetics, and neural activation of the traditional bench press movement performed explosively and the explosive bench throw in which the barbell was projected from the hands. Seventeen male subjects completed three trials with a bar weight of 45% of the subject's previously determined 1RM. Performance was significantly higher during the throw movement compared to the press for average velocity, peak velocity, average force, average power, and peak power. Average muscle activity during the concentric phase for pectoralis major, anterior deltoid, triceps brachii, and biceps brachii was higher for the throw condition. It was concluded that performing traditional press movements rapidly with light loads does not create ideal loading conditions for the neuromuscular system with regard to explosive strength production, especially in the final stages of the movement, because ballistic weight loading conditions where the resistance was accelerated throughout the movement resulted in a greater velocity of movement, force output, and EMG activity.

scholarly journals Modulation of Stretch Reflexes of the Finger Flexors by Sensory Feedback From the Proximal Upper Limb Poststroke

2009 ◽  
Vol 102 (3) ◽  
pp. 1420-1429 ◽  
Author(s):  
Gilles Hoffmann ◽  
Derek G. Kamper ◽  
Jennifer H. Kahn ◽  
William Z. Rymer ◽  
Brian D. Schmit
Keyword(s):  
Upper Limb ◽  
Stretch Reflex ◽  
Sensory Input ◽  
Biceps Brachii ◽  
Elbow Flexion ◽  
Spinal Reflex ◽  
Reflex Response ◽  
Emg Activity ◽  
Triceps Brachii ◽  
Flexor Digitorum

Neural coupling of proximal and distal upper limb segments may have functional implications in the recovery of hemiparesis after stroke. The goal of the present study was to investigate whether the stretch reflex response magnitude of spastic finger flexor muscles poststroke is influenced by sensory input from the shoulder and the elbow and whether reflex coupling of muscles throughout the upper limb is altered in spastic stroke survivors. Through imposed extension of the metacarpophalangeal (MCP) joints, stretch of the relaxed finger flexors of the four fingers was imposed in 10 relaxed stroke subjects under different conditions of proximal sensory input, namely static arm posture (3 different shoulder/elbow postures) and electrical stimulation (surface stimulation of biceps brachii or triceps brachii, or none). Fast (300°/s) imposed stretch elicited stretch reflex flexion torque at the MCP joints and reflex electromyographic (EMG) activity in flexor digitorum superficialis. Both measures were greatest in an arm posture of 90° of elbow flexion and neutral shoulder position. Biceps stimulation resulted in greater MCP stretch reflex flexion torque. Fast imposed stretch also elicited reflex EMG activity in nonstretched heteronymous upper limb muscles, both proximal and distal. These results suggest that in the spastic hemiparetic upper limb poststroke, sensorimotor coupling of proximal and distal upper limb segments is involved in both the increased stretch reflex response of the finger flexors and an increased reflex coupling of heteronymous muscles. Both phenomena may be mediated through changes poststroke in the spinal reflex circuits and/or in the descending influence of supraspinal pathways.

scholarly journals Activity of upper limb and trunk muscles during power walking

2015 ◽  
Vol 9 (2) ◽  
Author(s):  
Johann Peter Kuhtz-Buschbeck ◽  
Antonia Frendel
Keyword(s):  
Upper Limb ◽  
Muscle Activation ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Emg Activity ◽  
Normal Walking ◽  
Arm Swing ◽  
Temporal Muscle ◽  
Limb Muscles ◽  
Emg Patterns

<p>Background: Arm swing is deliberately emphasized during power walking, a popular aerobic fitness exercise. Electromyographic (EMG) activation curves of arm and shoulder muscles during power walking have not yet been examined. Aim: To describe the amount and pattern of EMG activity of upper limb muscles during power walking. Data are compared to normal walking and jogging. Method:  Twenty volunteers were examined on a treadmill at 6 km/h during (a) normal walking, (b) power walking, (c) jogging. EMG data were collected for the trapezius (TRAP), anterior (AD) and posterior deltoid (PD), biceps (BIC), triceps (TRI), latissimus dorsi (LD) and erector spinae (ES) muscles. Results:  Activity of four muscles (AD, BIC, PD, TRAP) was three- to fivefold stronger during power walking than normal walking. Smaller significant increases involved the TRI, LD and ES. Two muscles (AD, TRAP) were more active during power walking than running. Normal walking and power walking involved similar EMG patterns of PD, LD, ES, while EMG patterns of running and walking differed. Interpretation: Emphasizing arm swing during power walking triples the EMG activity of upper limb muscles, compared to normal walking. Similar basic temporal muscle activation patterns in both modes of walking indicate a common underlying motor program. </p>

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