EMG, Force, and Power Analysis of Sprint-Specific Strength Exercises

1994 ◽  
Vol 10 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Antti Mero ◽  
Paavo V. Komi
Keyword(s):  
Muscle Power ◽  
Emg Activity ◽  
Specific Strength ◽  
Leg Muscles ◽  
Strength Exercises ◽  
Stride Rate ◽  
Emg Patterns ◽  
Force Time ◽  
The Right ◽  
Resultant Forces

This study was undertaken to compare force-time characteristics, muscle power, and electromyographic (EMG) activities of the leg muscles in maximal sprinting and in selected bounding and jumping exercises. Seven male sprinters performed maximal bounding (MB), maximal stepping (MS), maximal hopping with the right (MHR) and left (MHL) legs, and maximal sprint running (MR). These “horizontal” exercises and running were performed on a force platform. EMG activity was telemetered unilaterally from five leg muscles during each trial. The results indicated significant (p < .001) differences among the studied exercises in velocity, stride length, stride rate, flight time, and contact time. Also, significant differences were noticed in reactive forces (p < .01-.001) and power (p < .01) among the performances, whereas only insignificant differences were observed in EMG patterns. The average resultant forces during the braking and propulsion phases in MS, MHR, and MHL were greater (p < .001) than in MR and MB. Stepping and hopping are cyclic and sprint-specific and may be used as strength exercises for sprinters because of great strength demand.

Smooth changes in the EMG patterns during gait transitions under body weight unloading

2011 ◽  
Vol 106 (3) ◽  
pp. 1525-1536 ◽  
Author(s):  
Francesca Sylos Labini ◽  
Yuri P. Ivanenko ◽  
Germana Cappellini ◽  
Silvio Gravano ◽  
Francesco Lacquaniti
Keyword(s):  
Body Weight ◽  
Central Pattern Generators ◽  
Emg Activity ◽  
Motor Patterns ◽  
Leg Muscles ◽  
Weight Support ◽  
Emg Patterns ◽  
Pattern Generators ◽  
Smooth Transitions ◽  
Gait Transitions

During gradual speed changes, humans exhibit a sudden discontinuous switch from walking to running at a specific speed, and it has been suggested that different gaits may be associated with different functioning of neuronal networks. In this study we recorded the EMG activity of leg muscles at slow increments and decrements in treadmill belt speed and at different levels of body weight unloading. In contrast to normal walking at 1 g, at lower levels of simulated gravity (<0.4 g) the transition between walking and running was generally gradual, without systematic abrupt changes in either intensity or timing of EMG patterns. This phenomenon depended to a limited extent on the gravity simulation technique, although the exact level of the appearance of smooth transitions (0.4–0.6 g) tended to be lower for the vertical than for the tilted body weight support system. Furthermore, simulations performed with a half-center oscillator neuromechanical model showed that the abruptness of motor patterns at gait transitions at 1 g could be predicted from the distinct parameters anchored already in the normal range of walking and running speeds, whereas at low gravity levels the parameters of the model were similar for the two human gaits. A lack of discontinuous changes in the pattern of speed-dependent locomotor characteristics in a hypogravity environment is consistent with the idea of a continuous shift in the state of a given set of central pattern generators, rather than the activation of a separate set of central pattern generators for each distinct gait.

The Spatial Dependency of Shoulder Muscle Demands for Seated Lateral Hand Force Exertions

2014 ◽  
Vol 30 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Alison C. McDonald ◽  
Elora C. Brenneman ◽  
Alan C. Cudlip ◽  
Clark R. Dickerson
Keyword(s):  
Repeated Measures ◽  
Muscle Activation ◽  
Three Dimensional ◽  
Emg Activity ◽  
Hand Position ◽  
Individual Muscle ◽  
Repeated Measures Analysis ◽  
Spatial Parameters ◽  
Shoulder Complex ◽  
The Right

As the modern workplace is dominated by submaximal repetitive tasks, knowledge of the effect of task location is important to ensure workers are unexposed to potentially injurious demands imposed by repetitive work in awkward or sustained postures. The purpose of this investigation was to develop a three-dimensional spatial map of the muscle activity for the right upper extremity during laterally directed submaximal force exertions. Electromyographic (EMG) activity was recorded from fourteen muscles surrounding the shoulder complex as the participants exerted 40N of force in two directions (leftward, rightward) at 70 defined locations. Hand position in both push directions strongly influenced total and certain individual muscle demands as identified by repeated measures analysis of variance (P< .001). During rightward exertions individual muscle activation varied from 1 to 21% MVE and during leftward exertions it varied from 1 to 27% MVE with hand location. Continuous prediction equations for muscular demands based on three-dimensional spatial parameters were created with explained variance ranging from 25 to 73%. The study provides novel information for evaluating existing and proactive workplace designs, and may help identify preferred geometric placements of lateral exertions in occupational settings to lower muscular demands, potentially mitigating fatigue and associated musculoskeletal risks.

Survei Kondisi Fisik Sepak Bola pada Pemain Arema Football Academy Usia 16 Tahun di Kota Malang Tahun 2021

2021 ◽  
Vol 3 (12) ◽  
pp. 1032-1041
Author(s):  
Maulana Khoiru Rofik ◽  
Moch. Yunus ◽  
Prisca Widiawati
Keyword(s):  
Muscle Strength ◽  
Physical Condition ◽  
Muscle Power ◽  
Football Players ◽  
Leg Muscles ◽  
Good Physical Condition ◽  
Leg Muscle ◽  
Real Picture ◽  
Leg Muscle Power

Abstract: Physical condition is an important role in football because with good physical condition, it will be more likely to achieve. This study aims to determine the level of physical condition of Arema players aged 16 years in Malang City in 2021. The method used in this study is descriptive quantitative which aims to provide a real picture in accordance with what is in the field about the physical condition of Arema Football Academy football players aged 16 years old in Malang in 2021. The results on leg muscle strength have an average of 44.24, speed has an average of 7.73, agility has an average of 9.91, flexibility has an average of 16.60, muscle power limbs have an average of 55.88, endurance has an average of 45.98. It can be concluded that strength (leg muscles) is in sufficient category, speed is in good category, agility is in very good category, flexibility is in very good category, leg muscle power is in good category and endurance is in good category. And the overall physical condition is in the sufficient category. Abstrak: Kondisi fisik merupakan peranan yang penting dalam sepak bola karena dengan kondisi fisik yang baik maka akan lebih berpeluang untuk berprestasi. Penelitian ini bertujuan untuk mengetahui tingkat kondisi fisik pemain arema usia 16 tahun di Kota Malang tahun 2021. Metode yang digunakan dalam penelitian ini merupakan kuantitatif deskriptif yang bertujuan untuk memberikan gambaran nyata sesuai dengan yang ada di lapangan tentang kondisi fisik pemain sepak bola Arema Football Academy umur 16 tahun di Kota Malang tahun 2021. Hasil pada kekuatan otot tungkai memiliki rata-rata 44,24, kecepatan memiliki rata-rata 7,73, kelincahan memiliki rata-rata 9,91, kelentukan memiliki rata-rata 16,60, power otot tungkai memiliki rata-rata 55,88, daya tahan memiliki rata-rata 45,98. Dapat disimpulkan bahwa kekuatan (otot tungkai) masuk kategori cukup, kecepatan masuk kategori baik, kelincahan masuk kategori baik sekali, kelentukan masuk kategori baik sekali, power otot tungkai masuk kategori baik dan daya tahan masuk kategori baik. Dan pada kondisi fisik secara keseluruhan masuk dalam kategori cukup.

scholarly journals Geniohyoid muscle function in awake canines

2003 ◽  
Vol 95 (2) ◽  
pp. 810-817 ◽  
Author(s):  
M. Yokoba ◽  
H. G. Hawes ◽  
P. A. Easton
Keyword(s):  
Muscle Function ◽  
Breathing Pattern ◽  
Muscle Length ◽  
Upper Airway ◽  
Mechanical Action ◽  
Emg Activity ◽  
Airway Occlusion ◽  
Lateral Decubitus ◽  
The Right ◽  
Emg Electrodes

The geniohyoid (Genio) upper airway muscle shows phasic, inspiratory electrical activity in awake humans but no activity and lengthening in anesthetized cats. There is no information about the mechanical action of the Genio, including length and shortening, in any awake, nonanesthetized mammal during respiration (or swallowing). Therefore, we studied four canines, mean weight 28.8 kg, 1.5 days after Genio implantation with sonomicrometry transducers and bipolar electromyogram (EMG) electrodes. Awake recordings of breathing pattern, muscle length and shortening, and EMG activity were made with the animal in the right lateral decubitus position during quiet resting, CO2-stimulated breathing, inspiratory-resisted breathing (80 cmH2O · l-1 · s), and airway occlusion. Genio length and activity were also measured during swallowing, when it shortened, showing a 9.31% change from resting length, and its EMG activity increased 6.44 V. During resting breathing, there was no phasic Genio EMG activity at all, and Genio showed virtually no movement during inspiration. During CO2-stimulated breathing, Genio showed minimal lengthening of only 0.07% change from resting length, whereas phasic EMG activity was still absent. During inspiratory-resisted breathing and airway occlusion, Genio showed phasic EMG activity but still lengthened. We conclude that the Genio in awake, nonanesthetized canines shows active contraction and EMG activity only during swallowing. During quiet or stimulated breathing, Genio is electrically inactive with passive lengthening. Even against resistance, Genio is electrically active but still lengthens during inspiration.

The Relationship between Integrated EMG and Oxygen Uptake during Treadmill and Bicycle Exercise

1976 ◽  
Vol 20 (23) ◽  
pp. 548-551
Author(s):  
T. Fukunaga ◽  
K. Yuasa ◽  
M. Kobayashi ◽  
T. Miyagawa ◽  
H. Fujimatsu ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Correlation Coefficient ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Treadmill Walking ◽  
Emg Activity ◽  
Bicycle Exercise ◽  
Leg Muscles ◽  
Integrated Emg ◽  
Muscle Groups

The aim of this study is to measure the integrated EMG in relation to the oxygen uptake during submaximal treadmill and bicycle exercises. Seven healthy adult subjects performed five minute exercise at three different submaximal work intensities on the same day. The EMG activity in right thigh and leg muscles was measured from m. rectus femoris, m. biceps femoris, m. tibialis anterior and m. gastrocnemius by means of four pairs of surface electrodes sealed with collodion to the skin at a distance of 3 cm apart over the belly of muscles. The EMG activity was not likely modified by the possible fatigue during 5 minutes submaximal exercise in this experiment. In the treadmill walking, there was a rectilinear relationship between integrated EMG activity from four muscle groups and percent of VO2max. On the bicycle exercise the correlation coefficient between them was generally lower than that on the treadmill walking. The product of integrated EMG and volume of the same muscle groups was considerably linearly related to oxygen uptake during treadmill and bicycle exercise (the correlation coefficient was 0.945, p < 0.001 in treadmill and 0.710, p < 0.001 in bicycle).

Features of Cortically Evoked Swallowing in the Awake Primate (Macaca fascicularis)

1999 ◽  
Vol 82 (3) ◽  
pp. 1529-1541 ◽  
Author(s):  
Ruth E. Martin ◽  
Pentti Kemppainen ◽  
Yuji Masuda ◽  
Dongyuan Yao ◽  
Gregory M. Murray ◽  
...  
Keyword(s):  
Macaca Fascicularis ◽  
Primary Motor Cortex ◽  
Solid Material ◽  
Emg Activity ◽  
Pulse Trains ◽  
Orofacial Movements ◽  
The Face ◽  
Frontal Operculum ◽  
Emg Patterns ◽  
Cortical Regions

Although the cerebral cortex has been implicated in the control of swallowing, the output organization of the cortical swallowing representation, and features of cortically evoked swallowing, remain unclear. The present study defined the output features of the primate “cortical swallowing representation” with intracortical microstimulation (ICMS) applied within the lateral sensorimotor cortex. In four hemispheres of two awake monkeys, microelectrode penetrations were made at ≤1-mm intervals, initially within the face primary motor cortex (face-MI), and subsequently within the cortical regions immediately rostral, lateral, and caudal to MI. Two ICMS pulse trains [35-ms train, 0.2-ms pulses at 333 Hz, ≤30 μA (short train stimulus, T/S); 3- to 4-s train, 0.2-ms pulses at 50 Hz, ≤60 μA (continuous stimulus, C/S)] were applied at ≤500-μm intervals along each microelectrode penetration to a depth of 8–10 mm, and electromyographic (EMG) activity was recorded simultaneously from various orofacial and laryngeal muscles. Evoked orofacial movements, including swallowing, were verified by EMG analysis, and T/S and C/S movement thresholds were determined. Effects of varying ICMS intensity on swallow-related EMG properties were examined by applying suprathreshold C/S at selected intracortical sites. EMG patterns of swallows evoked from various cortical regions were compared with those of natural swallows recorded as the monkeys swallowed liquid and solid material. Results indicated that swallowing was evoked by C/S at ∼20% of 1,569 intracortical sites where ICMS elicited an orofacial motor response in both hemispheres of the two monkeys, typically at C/S intensities ≤30 μA. In contrast, swallowing was not evoked by T/S in either monkey. Swallowing was evoked from four cortical regions: the ICMS-defined face-MI, the face primary somatosensory cortex (face-SI), the region lateral and anterior to face-MI corresponding to the cortical masticatory area (CMA), and an area >5 mm deep to the cortical surface corresponding to both the white matter underlying the CMA and the frontal operculum; EMG patterns of swallows elicited from these four cortical regions showed some statistically significant differences. Whereas swallowing only was evoked at some sites, particularly within the deep cortical area, swallowing was more frequently evoked together with other orofacial responses including rhythmic jaw movements. Increasing ICMS intensity increased the magnitude, and decreased the latency, of the swallow-related EMG burst in the genioglossus muscle at some sites. These findings suggest that a number of distinct cortical foci may participate in the initiation and modulation of the swallowing synergy as well as in integrating the swallow within the masticatory sequence.

scholarly journals Electromyographic activity of the vastus medialis and gastrocnemius implicates a slow stretch-shortening cycle during rowing in the field

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Steffen Held ◽  
Tobias Siebert ◽  
Lars Donath
Keyword(s):  
Performance Enhancement ◽  
Muscular Activity ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Vastus Medialis ◽  
Leg Muscles ◽  
Rowing Performance ◽  
Specific Muscle ◽  
Two Phases ◽  
Activation Phase

Abstract The consideration of the temporal and electromyographic (EMG) characteristics of stretch-shortening cycles (SSC) are crucial for the conceptualization of discipline-specific testing and training. Since leg muscles are first stretched (eccentric) and then contracted (concentric) during rowing, it can be assumed that the entire muscle tendon complex performs a SSC. Thus, it should be elucidated whether the rowing cycle can be attributed to either a slow or fast SSC. Therefore, EMG of the vastus medialis and gastrocnemius were captured (n = 10, 22.8 ± 3.1 years, 190 ± 6 cm, 82.1 ± 9.8 kg) during (single scull) rowing and subsequently compared to typical slow (countermovement jump, CMJ) and fast (drop jump, DJ) SSCs. The elapsed time between the EMG onset and the start of the eccentric phase was monitored. The pre-activation phase (PRE, before the start of the eccentric phase) and the reflex-induced activation phase (RIA 30–120 ms after the start of the eccentric phase) have been classified. Notable muscular activity was observed during DJ before the start of the eccentric phase (PRE) as well as during RIA. In contrast, neither CMJ nor rowing revealed any EMG-activity in these two phases. Interestingly, CMJ and race-specific rowing showed an EMG-onset during the eccentric phase. We conclude that rowing is more attributable to a slow SSC and implies that fast SSC does not reflect discipline specific muscle action and could hamper rowing-performance-enhancement.

Specificity of esophageal electrode recordings of posterior cricoarytenoid muscle activity

1989 ◽  
Vol 66 (3) ◽  
pp. 1501-1505 ◽  
Author(s):  
G. Insalaco ◽  
G. Sant'Ambrogio ◽  
F. B. Sant'Ambrogio ◽  
S. T. Kuna ◽  
O. P. Mathew
Keyword(s):  
Marked Decrease ◽  
Upper Airway ◽  
Emg Activity ◽  
Small Reduction ◽  
Posterior Cricoarytenoid Muscle ◽  
Intramuscular Electrodes ◽  
Inspiratory Activity ◽  
Recorded Activity ◽  
Posterior Cricoarytenoid ◽  
The Right

Esophageal electrodes have been used for recording the electromyographic (EMG) activity of the posterior cricoarytenoid muscle (PCA). To determine the specificity of this EMG technique, esophageal electrode recordings were compared with intramuscular recordings in eight anesthetized mongrel dogs. Intramuscular wire electrodes were placed in the right and left PCA, and the esophageal electrode was introduced through the nose or mouth and advanced into the upper esophagus. On direct visualization of the upper airway, the unshielded catheter electrode entered the esophagus on the right or left side. Cold block of the recurrent laryngeal nerve (RLN) ipsilateral to the esophageal electrode was associated with a marked decrease in recorded activity, whereas cold block of the contralateral RLN resulted only in a small reduction in activity. After supplemental doses of anesthesia were administered, bilateral RLN cold block essentially abolished the activity recorded with the intramuscular electrodes as well as that recorded with the esophageal electrode. Before supplemental doses of anesthesia were given, especially after vagotomy, the esophageal electrode, and in some cases the intramuscular electrodes, recorded phasic inspiratory activity not originating from the PCA. Therefore, one should be cautious in interpreting the activity recorded from esophageal electrodes as originating from the PCA, especially in conditions associated with increased respiratory efforts.

Treadmill vs. floor walking: kinematics, electromyogram, and heart rate

1985 ◽  
Vol 59 (1) ◽  
pp. 87-91 ◽  
Author(s):  
M. P. Murray ◽  
G. B. Spurr ◽  
S. B. Sepic ◽  
G. M. Gardner ◽  
L. A. Mollinger
Keyword(s):  
Heart Rate ◽  
Stride Length ◽  
Sagittal Plane ◽  
Treadmill Walking ◽  
Emg Activity ◽  
Normal Female ◽  
Emg Patterns ◽  
Female Subjects

To identify the degree of difference between treadmill and floor walking, kinematic, electromyographic (EMG), and heart rate measurements were recorded in seven normal female subjects during walking at three speeds on the treadmill and on the floor. During treadmill walking, subjects tended to use a faster cadence and shorter stride length than during floor walking. In addition the displacements of the head, hip, and ankle in the sagittal plane showed statistically significant differences between floor and treadmill walking. Average EMG activity was usually greater on the treadmill than on the floor; however, this difference was only significant for the quadriceps. Heart rate was significantly higher during fast treadmill walking than floor walking. In general, treadmill walking was not found to differ markedly from floor walking in kinematic measurements or EMG patterns.

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