Long-term activity in upper- and lower-limb muscles of humans

2001 ◽  
Vol 91 (5) ◽  
pp. 2224-2232 ◽  
Author(s):  
Drew S. Kern ◽  
John G. Semmler ◽  
Roger M. Enoka

Despite limited data on humans, previous studies suggest that there is an association between the duration of daily muscle activity and the proportion of type I muscle fibers. We quantified the activity of limb muscles in healthy men and women during normal use and compared these measurements with published reports on fiber-type proportions. Seven men (age range = 21–28 yr) and seven women (age range = 18–26 yr) participated in two 10-h recording sessions. Electromyogram (EMG) activity of four muscles in nondominant upper (first dorsal interosseus and biceps brachii) and lower limbs (vastus medialis and vastus lateralis) was recorded with surface electrodes. Hand and arm muscles were active for 18% of the recording time, whereas leg muscles were active for only 10% of the recording time. On average, upper-limb muscles were activated 67% more often than lower-limb muscles. When lower-limb muscles were activated, however, the mean amplitude of each burst was greater in leg muscles [18 and 17% maximum voluntary contraction (MVC)] compared with hand (8% MVC) and arm (6% MVC) muscles. Temporal association in activity between pairs of muscles was high for the two lower-limb muscles ( r 2 = 0.7) and relatively weak for the two upper-limb muscles ( r 2 = 0.09). Long-term muscle activity was only different between men and women for the biceps brachii muscle. We found no relation between duration of muscle activity in 10-h recordings and the reported values of type I fibers in men and women.

2013 ◽  
Vol 109 (8) ◽  
pp. 1996-2006 ◽  
Author(s):  
Hidehito Tomita ◽  
Yoshiki Fukaya ◽  
Kenji Totsuka ◽  
Yuri Tsukahara

This study aimed to determine whether individuals with spastic diplegic cerebral palsy (SDCP) have deficits in anticipatory inhibition of postural muscle activity. Nine individuals with SDCP (SDCP group, 3 female and 6 male, 13–24 yr of age) and nine age- and sex-matched individuals without disability (control group) participated in this study. Participants stood on a force platform, which was used to measure the position of the center of pressure (CoP), while holding a light or heavy load in front of their bodies. They then released the load by abducting both shoulders. Surface electromyograms were recorded from the rectus abdominis, erector spinae (ES), rectus femoris (RF), medial hamstring (MH), tibialis anterior (TA), and gastrocnemius (GcM) muscles. In the control group, anticipatory inhibition before load release and load-related modulation of the inhibition were observed in all the dorsal muscles recorded (ES, MH, and GcM). In the SDCP group, similar results were obtained in the trunk muscle (ES) but not in the lower limb muscles (MH and GcM), although individual differences were seen, especially in MH. Anticipatory activation of the ventral lower limb muscles (RF and TA) and load-related modulation of the activation were observed in both participant groups. CoP path length during load release was longer in the SDCP group than in the control group. The present findings suggest that individuals with SDCP exhibit deficits in anticipatory inhibition of postural muscles at the dorsal part of the lower limbs, which is likely to result in a larger disturbance of postural equilibrium.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Jinzhuang Xiao ◽  
Jinli Sun ◽  
Junmin Gao ◽  
Hongrui Wang ◽  
Xincai Yang

Objectives. Prone bridge, unilateral bridge, supine bridge, and bird-dog are classic rehabilitation exercises, which have been advocated as effective ways to improve core stability among healthy individuals and patients with low back pain. The aim of this study was to investigate the activity of seven selected muscles during rehabilitation exercises through the signal of surface electromyographic. Approaches. We measured the surface electromyographic signals of four lower limb muscles, two abdominal muscles, and one back muscle during rehabilitation exercises of 30 healthy students and then analyzed its activity level using the median frequency method. Results. Different levels of muscle activity during the four rehabilitation exercises were observed. The prone bridge and unilateral bridge caused the greatest muscle fatigue; however, the supine bridge generated the lowest muscle activity. There was no significant difference (P>0.05) between left and right body side muscles in the median frequency slope during the four rehabilitation exercises of seven muscles. Conclusions. The prone bridge can affect the low back and lower limb muscles of most people. The unilateral bridge was found to stimulate muscles much more active than the supine bridge. The bird-dog does not cause much fatigue to muscles but can make most selected muscles active.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Aisha Islam ◽  
Lisa Alcock ◽  
Kianoush Nazarpour ◽  
Lynn Rochester ◽  
Annette Pantall

Abstract Gait deficits are a common feature of Parkinson’s disease (PD) and predictors of future motor and cognitive impairment. Understanding how muscle activity contributes to gait impairment and effects of therapeutic interventions on motor behaviour is crucial for identifying potential biomarkers and developing rehabilitation strategies. This article reviews sixteen studies that investigate the electromyographic (EMG) activity of lower limb muscles in people with PD during walking and reports on their quality. The weight of evidence establishing differences in motor activity between people with PD and healthy older adults (HOAs) is considered. Additionally, the effect of dopaminergic medication and deep brain stimulation (DBS) on modifying motor activity is assessed. Results indicated greater proximal and decreased distal activity of lower limb muscles during walking in individuals with PD compared to HOA. Dopaminergic medication was associated with increased distal lower limb muscle activity whereas subthalamic nucleus DBS increased activity of both proximal and distal lower limb muscles. Tibialis anterior was impacted most by the interventions. Quality of the studies was not strong, with a median score of 61%. Most studies investigated only distal muscles, involved small sample sizes, extracted limited EMG features and lacked rigorous signal processing. Few studies related changes in motor activity with functional gait measures. Understanding mechanisms underpinning gait impairment in PD is essential for development of personalised rehabilitative interventions. Recommendations for future studies include greater participant numbers, recording more functionally diverse muscles, applying multi-muscle analyses, and relating EMG to functional gait measures.


1997 ◽  
Vol 77 (6) ◽  
pp. 3401-3405 ◽  
Author(s):  
Stephan Salenius ◽  
Karin Portin ◽  
Matti Kajola ◽  
Riitta Salmelin ◽  
Riitta Hari

Salenius, Stephan, Karin Portin, Matti Kajola, Riitta Salmelin, and Riitta Hari. Cortical control of human motoneuron firing during isometric contraction. J. Neurophysiol. 77: 3401–3405, 1997. We recorded whole scalp magnetoencephalographic (MEG) signals simultaneously with the surface electromyogram from upper and lower limb muscles of six healthy right-handed adults during voluntary isometric contraction. The 15- to 33-Hz MEG signals, originating from the anterior bank of the central sulcus, i.e., the primary motor cortex, were coherent with motor unit firing in all subjects and for all muscles. The coherent cortical rhythms originated in the hand motor area for upper limb muscles (1st dorsal interosseus, extensor indicis proprius, and biceps brachii) and close to the foot area for lower limb muscles (flexor hallucis brevis). The sites of origin corresponding to different upper limb muscles did not differ significantly. The cortical signals preceded motor unit firing by 12–53 ms. The lags were shortest for the biceps brachii and increased systematically with increasing corticomuscular distance. We suggest that the motor cortex drives the spinal motoneuronal pool during sustained contractions, with the observed cortical rhythmic activity influencing the timing of efferent commands. The cortical rhythms could be related to motor binding, but the rhythmic output may also serve to optimize motor cortex output during isometric contractions.


2011 ◽  
Vol 175-176 ◽  
pp. 832-836 ◽  
Author(s):  
Ya Ning Li ◽  
A Ming Lu ◽  
Xiao Qun Dai ◽  
Jin Ao Chen ◽  
Xiao Wen Zhao

Recently, it has been reported that suitable garment pressure contributes to accelerating human blood circulation, improving sports performance and alleviating sports fatigue. In this study, effect of pressure exerted by knee-high gradient compression socks (GCS) on the lower limb muscles was investigated. Two healthy male college students volunteered to participate in this study. They were asked to run on a treadmill at a speed of 10 km/h with a GCS worn on one leg and a usual sports sock worn on the other leg until being tired out. During running, the surface electromyography (sEMG) of two lower limb muscles —— gastrocnemius medialis of the right leg (R-GM) and the left leg (L-GM) was recorded simultaneously. It was found that: pressure exerted on the lower limb by GCS gradually decreased from ankle to below-knee; GCS pressure helped to reduce muscle oscillation; wearing GCS seemed to help to reduce muscle fatigue during running.


2021 ◽  
Vol 33 (4) ◽  
pp. 868-876
Author(s):  
Tsutomu Togoe ◽  
Pham Hoang Tung ◽  
Koki Honda ◽  
Yasutaka Nakashima ◽  
Motoji Yamamoto ◽  
...  

Human standing stability was evaluated using a swash plate drop device in a disturbance application. Under different experimental conditions using the device, electromyogram (EMG) measurements showed that the left and right lower limb muscles were used differently. It also demonstrated that the dynamics also differed depending on the experimental conditions. In particular, the dynamics of standing stabilization in a tandem standing position and a normal standing position significantly differed, and the activities of related muscles were also significantly different; this indicates that standing stability may potentially depend on the subjects. These results indicate the need for the comprehensive consideration of the standing and disturbance conditions during the quantitative evaluation of human standing stability.


2014 ◽  
Vol 20 (6) ◽  
pp. 675-691 ◽  
Author(s):  
Blair Calancie ◽  
Miriam L. Donohue ◽  
Colin B. Harris ◽  
Gregory W. Canute ◽  
Amit Singla ◽  
...  

Object Reports of the accuracy of existing neuromonitoring methods for detecting or preventing medial malpositioning of thoracic pedicle screws have varied widely in their claimed effectiveness. The object of this study was to develop, test, and validate a novel neuromonitoring method for preventing medial malpositioning of pedicle screws in the thoracic spine during surgery. Methods This is a prospective, blinded and randomized study using a novel combination of input (4-pulse stimulus trains delivered within the pedicle track) and output (evoked electromyography from leg muscles) to detect pedicle track trajectories that—once implanted with a screw—would cause that screw to breach the pedicle's medial wall and encroach upon the spinal canal. For comparison, the authors also used screw stimulation as an input and evoked electromyogram from intercostal and abdominal muscles as output measures. Intraoperative electrophysiological findings were compared with postoperative CT scans by multiple reviewers blinded to patient identity or intraoperative findings. Results Data were collected from 71 patients, in whom 802 screws were implanted between the T-1 and L-1 vertebral levels. A total of 32 screws ended up with screw threads encroaching on the spinal canal by at least 2 mm. Pulse-train stimulation within the pedicle track using a ball-tipped probe and electromyography from lower limb muscles correctly predicted all 32 (100%) of these medially malpositioned screws. The combination of pedicle track stimulation and electromyogram response from leg muscles proved to be far more effective in predicting these medially malpositioned screws than was direct screw stimulation and any of the target muscles (intercostal, abdominal, or lower limb muscles) we monitored. Based on receiver operating characteristic analysis, the combination of 10-mA (lower alarm) and 15-mA stimulation intensities proved most effective for detection of pedicle tracks that ultimately gave rise to medially malpositioned screws. Additional results pertaining to the impact of feedback of these test results on surgical decision making are provided in the companion report. Conclusions This novel neuromonitoring approach accurately predicts medially malpositioned thoracic screws. The approach could be readily implemented within any surgical program that is already using contemporary neuromonitoring methods that include transcranial stimulation for monitoring motor evoked potentials.


2010 ◽  
Vol 109 (4) ◽  
pp. 1086-1095 ◽  
Author(s):  
Junichi Ushiyama ◽  
Yuji Takahashi ◽  
Junichi Ushiba

It has been well documented that the 15- to 35-Hz oscillatory activity of the sensorimotor cortex shows coherence with the muscle activity during weak to moderate steady contraction. To investigate the muscle dependency of the corticomuscular coherence and its training-related alterations, we quantified the coherence between electroencephalogram (EEG) from the sensorimotor cortex and rectified electromyogram (EMG) from five upper limb (first dorsal interosseous, flexor carpi radialis, extensor carpi radialis, biceps brachii, triceps brachii) and four lower limb muscles (soleus, tibialis anterior, biceps femoris, rectus femoris), while maintaining a constant force level at 30% of maximal voluntary contraction of each muscle, in 24 untrained, 12 skill-trained (ballet dancers), and 10 strength-trained (weightlifters) individuals. Data from untrained subjects demonstrated the muscle dependency of corticomuscular coherence. The magnitude of the EEG-EMG coherence was significantly greater in the distally located lower limb muscles, such as the soleus and tibialis anterior, than in the upper or other lower limb muscles in untrained subjects ( P < 0.05). These results imply that oscillatory coupling between the sensorimotor cortex and spinal motoneurons during steady contraction differs among muscles, according to the functional role of each muscle. In addition, the ballet dancers and weightlifters showed smaller EEG-EMG coherences than the untrained subjects, especially in the lower limb muscles ( P < 0.05). These results indicate that oscillatory interaction between the sensorimotor cortex and spinal motoneurons can be changed by long-term specialized use of the muscles and that this neural adaptation may lead to finer control of muscle force during steady contraction.


2016 ◽  
Vol 30 (3) ◽  
pp. 69-80
Author(s):  
Kinga Żebrowska ◽  
Katarzyna Homoncik

Abstract Introduction: This study sought to assess the influence of proper foot arch on electromyographic activity of selected lower limb muscles. The aim of this work was to evaluate the effects of foot arch on the activity of selected muscles and to determine whether electromyography might help to identify types of flat feet resulting from muscle- or ligament-related causes. Material and methods: The experiment involved 24 students of the Faculty of Rehabilitation, University of Physical Education in Warsaw. To determine Clarke’s angle, all study participants were examined with a podoscope. Based on the obtained results, the subjects were divided into two groups. The experimental group consisted of 12 individuals with low foot arches, while the control group included students with proper foot arches. The surface EMG (sEMG) signal was recorded from the following muscles: peroneus longus, tibialis anterior, gastrocnemius and soleus. First, the sEMG signal was recorded while measuring MVC for ankle extensors and flexors. Then, it was recorded in the following positions: free standing, two-leg standing on tiptoe, one-leg standing on tiptoe, pressing the first metatarsal head to the ground standing on heels. Results: No significant differences in muscle activity between the groups with low and proper foot arches were noted (p>0.05). Muscle activity did not prove to be a differentiating factor. Moreover, no differences were found in torques of ankle extensors and flexors between both groups. Conclusions: The findings of the study confirmed the hypothesis that the size of the foot arch had no effect on electromyographic activity of lower limb muscles. It was also revealed that flat feet did not lead to the weakening of muscle strength of ankle flexors and extensors.


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