Stepwise increase of upper limb muscle activity induced by progressive 4 positions of a handstand training

2021 ◽  
pp. 1-7
Author(s):  
Kazuaki Kinoshita ◽  
Yuichi Hoshino ◽  
Naoko Yokota ◽  
Masashi Hashimoto ◽  
Yuichiro Nishizawa ◽  
...  
Keyword(s):  
Upper Limb ◽  
Muscle Activity ◽  
Latissimus Dorsi ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Limb Muscle ◽  
Serratus Anterior ◽  
Muscle Loading ◽  
Lower Trapezius ◽  
Different Levels

BACKGROUND: Handstand is the most important fundamental skill in gymnastics. A gradual and well-balanced increase in muscle loading in a manner is preferred for young beginners and/or recovering gymnasts to safely achieve the muscle strength required to perform a stable handstand. OBJECTIVE: To examine upper limb muscle activity during different levels of handstand training positions. METHODS: This study utilized four different positions for progressive handstand training; namely, the 90, 135, elbow stand, and handstand positions. The activities of eight upper limb muscles (upper, middle, and lower trapezius; serratus anterior; anterior and middle deltoid; infraspinatus; and latissimus dorsi were measured by surface electromyography (EMG) for each position. The percentages of EMG in each muscle compared to the values during maximum voluntary contraction were calculated and compared between the positions. RESULTS: Muscle activity around the shoulder increased gradually throughout the progression of the four handstand training positions. Furthermore, the muscles required for scapular stabilization, such as the upper and middle trapezius and serratus anterior muscles, were activated at levels similar to those for a handstand without performing this movement. CONCLUSIONS: A progressive handstand training program of four different positions resulted in gradual and well-balanced increases in muscle activity.

scholarly journals Shoulder Muscle Activity in Sport Climbing in Naturally Chosen and Corrected Shoulder Positions

2017 ◽  
Vol 10 (1) ◽  
pp. 107-113
Author(s):  
Jiří Baláš ◽  
Alena Duchačová ◽  
David Giles ◽  
Kateřina Kotalíková ◽  
David Pánek ◽  
...  
Keyword(s):  
Muscle Activity ◽  
External Rotation ◽  
Voluntary Contraction ◽  
The Other ◽  
Electromyographic Activity ◽  
Serratus Anterior ◽  
Upper Trapezius ◽  
Shoulder Muscle ◽  
Sport Climbing ◽  
Lower Trapezius

Objective:The aim of the study was to determine electromyographic activity of the scapula stabilizing muscles in naturally chosen and corrected shoulder positions in typical static climbing postures.Methods:Six male participants undertook surface electromyography measurement in four climbing postures for two different shoulder positions. The activity of the lower, middle and upper trapezius, serratus anterior, pectoralis major, and sternocleidomastoid was recorded. Electromyographic activity was expressed as the percentage of maximal voluntary contraction (MVC) for each muscle.Results:Climbing postures induced higher activation of middle and lower trapezius in corrected shoulder positions (35.3 ± 11.8 and 61.7 ± 15.4% MVC respectively) than in naturally chosen shoulder positions (18.4 ± 8.9 and 30.1 ± 13.8% MVC respectively). The highest activity of the middle and lower trapezius was found in postures with the arm in external rotation and 90° abduction and in an overhanging posture. Low activation was stated for the other muscles in both shoulder conditions.Conclusion:Results showed that climbers naturally elevate the shoulder during typical static postures. Corrected shoulder positions induce higher activation of the scapula stabilizing muscles than naturally chosen shoulder positions.

Association Between Lower Trapezius Isometric Strength and Y-Balance Test Upper Quarter Performance in College Volleyball Players

2021 ◽  
pp. 1-6
Author(s):  
Guillermo Mendez-Rebolledo ◽  
Ann M. Cools ◽  
Rodrigo Ramirez-Campillo ◽  
Elias Quiroz-Aldea ◽  
Fernanda A.P. Habechian
Keyword(s):  
Upper Limb ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Isometric Strength ◽  
Serratus Anterior ◽  
Balance Test ◽  
Cross Sectional ◽  
Convenience Sample ◽  
Volleyball Players ◽  
Lower Trapezius

Context: Knowing the possible association between the isometric strength of the shoulder rotators, scapular muscles, and the Y-balance test upper quarter (YBT-UQ) performance could help identify which indicators of shoulder stability should be considered in this field test. This study aimed to determine whether the isometric strength of the shoulder rotators and scapular muscles is associated with the YBT-UQ performance of the dominant upper limb in amateur volleyball players. Design: Cross-sectional study. Methods: A convenience sample of 22 male and 18 female volleyball players (≥12 h of training/week) between 18 and 26 years of age. The isometric strength of the middle trapezius, lower trapezius, serratus anterior, internal, and external rotator muscles was assessed with a handheld dynamometer. Participants performed the YBT-UQ in the superolateral, medial, and inferolateral directions. The absolute isometric peak force (in Newtons) was normalized to body weight (in Newtons per kilogram) for each muscle test. For each YBT-UQ direction, the distance (in centimeters) was normalized for upper limb length (in percentage). A backward multiple linear regression analysis was used to determine the associations between variables. Results: The analysis revealed that the isometric strength of the lower trapezius (β = 26.82; 95% confidence interval, 21.24–32.40) is associated with inferolateral YBT-UQ performance (adjusted R2 = .706; P < .001). This factor explains 70% of the variability of the YBT-UQ in the inferolateral direction. Conclusions: Lower trapezius isometric strength is associated with inferolateral YBT-UQ performance of the dominant upper limb in amateur volleyball players. These findings could help in the development of more specific training programs and rehabilitation goals according to the performance of the athletes in the test.

Upper extremity muscle activity during household floor vacuuming with upright cleaners

2018 ◽  
Vol 62 (1) ◽  
pp. 1018-1021
Author(s):  
Haerim Bak ◽  
Clive D’Souza ◽  
Gwanseob Shin
Keyword(s):  
Upper Extremity ◽  
Muscle Activity ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Activity Levels ◽  
Physical Demands ◽  
Study Results ◽  
Musculoskeletal Problems ◽  
Muscle Groups ◽  
Intensive Work

Physical demands of household carpet vacuuming and associated risks for musculoskeletal problems have received little attention although the level of muscle exertions is often assumed to be similar to that of occupational vacuuming. The aim of this study was to quantitatively assess the level of muscle activities of the upper extremity during carpeted floor vacuuming with household upright vacuum cleaners. Eighteen participants conducted four different carpet vacuuming tasks with two different cleaner models. Electromyography data from seven upper extremity muscles were collected. Median muscle activity ranged from 4.5% to 47.5% of the maximum voluntary contraction capacity for female participants and from 2.7% to 23.6% for male participants. Normalized muscle activity levels were significantly higher in women compared to men across tasks and muscle groups. Study results suggest that home vacuuming with upright vacuum cleaners is physically intensive work, especially for female users who are less physically capable.

Impact of posture and upper-limb muscle activity on grip strength

2018 ◽  
Vol 25 (4) ◽  
pp. 614-620 ◽  
Author(s):  
Rahul Jain ◽  
Makkhan Lal Meena ◽  
Manoj Kumar Sain ◽  
Govind Sharan Dangayach
Keyword(s):  
Grip Strength ◽  
Upper Limb ◽  
Muscle Activity ◽  
Limb Muscle

scholarly journals Single-Session Video and Electromyography Feedback in Overhead Athletes With Scapular Dyskinesis and Impingement Syndrome

2020 ◽  
Vol 55 (3) ◽  
pp. 265-273
Author(s):  
Wan-Yu Du ◽  
Tsun-Shun Huang ◽  
Yuan-Chun Chiu ◽  
Szu-Jieh Mao ◽  
Li-Wei Hung ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Training Group ◽  
Video Feedback ◽  
Emg Biofeedback ◽  
Scapular Dyskinesis ◽  
Serratus Anterior ◽  
Overhead Athletes ◽  
Feedback Training ◽  
Scapular Kinematics ◽  
Lower Trapezius

Context Subacromial impingement syndrome (SIS) is associated with scapular dyskinesis, or imbalanced scapular muscle activity. Evidence has shown that feedback can improve scapular control in patients with SIS. However, it is unknown whether real-time video feedback or electromyography (EMG) biofeedback is optimal for improving scapular kinematics and muscle activity during a functional task. Objective To compare the effects of video and EMG feedback sessions on absolute muscle activity (upper trapezius [UT], lower trapezius [LT], serratus anterior), muscle balance ratios (UT/LT, UT/serratus anterior), and scapular kinematics (anterior-posterior tilt, external-internal rotation, upward rotation) in SIS participants during arm elevation and lowering. Design Randomized controlled clinical trial. Setting Research laboratory. Patients or Other Participants Overhead athletes who were diagnosed with SIS and who also exhibited scapular dyskinesis (N = 41). Main Outcome Measure(s) Three-dimensional kinematics and EMG were recorded before and after feedback training. Results Lower trapezius muscle activity increased (4.2%–18%, P &lt; .011) and UT/LT decreased (0.56–1.17, P &lt; .013) in the EMG biofeedback training group as compared with those in the video feedback training group. Scapular upward rotation during arm elevation was higher in the video group than in the EMG group after feedback training (2.3°, P = .024). Conclusions The EMG biofeedback improved muscle control and video feedback improved the correction of scapular upward rotation in patients with SIS. Trial Registration Number ClinicalTrials.gov: NCT03252444.

scholarly journals Rapid and flexible whole body postural responses are evoked from perturbations to the upper limb during goal-directed reaching

2017 ◽  
Vol 117 (3) ◽  
pp. 1070-1083 ◽  
Author(s):  
Catherine R. Lowrey ◽  
Joseph Y. Nashed ◽  
Stephen H. Scott
Keyword(s):  
Upper Limb ◽  
Lower Limb ◽  
Muscle Activity ◽  
Whole Body ◽  
Limb Muscle ◽  
Behavioral Context ◽  
Body Balance ◽  
Postural Responses ◽  
Muscle Responses ◽  
Behavioral Goal

An important aspect of motor control is the ability to perform tasks with the upper limbs while maintaining whole body balance. However, little is known about the coordination of upper limb voluntary and whole body postural control after mechanical disturbances that require both upper limb motor corrections to attain a behavioral goal and lower limb motor responses to maintain whole body balance. The present study identified the temporal organization of muscle responses and center of pressure (COP) changes following mechanical perturbations during reaching. Our results demonstrate that muscle responses in the upper limb are evoked first (∼50 ms), with lower limb muscle activity occurring immediately after, in as little as ∼60 ms after perturbation. Hand motion was immediately altered by the load, while COP changes occurred after ∼100 ms, when lower limb muscle activity was already present. Our secondary findings showed that both muscle activity and COP changes were influenced by behavioral context (by altering target shape, circle vs. rectangle). Voluntary and postural actions initially directed the hand toward the center of both target types, but after the perturbation upper limb and postural responses redirected the hand toward different spatial locations along the rectangle. Muscle activity was increased for both upper and lower limbs when correcting to the circle vs. the rectangle, and these differences emerged as early as the long-latency epoch (∼75–120 ms). Our results demonstrate that postural responses are rapidly and flexibly altered to consider the behavioral goal of the upper limb. NEW & NOTEWORTHY The present work establishes that, when reaching to a target while standing, perturbations applied to the upper limb elicit a rapid response in lower limb muscles. Unlike voluntary movements, postural responses do not occur before corrections of the upper limb. We show the first evidence that corrective postural adjustments are modulated by upper limb behavioral context (target shape). Importantly, this indicates that postural responses take into account upper limb feedback for online control.

Wrist and Shoulder Muscle Activity Changes Across Computer Tasks

2002 ◽  
Vol 46 (13) ◽  
pp. 1129-1132 ◽  
Author(s):  
Jack Dennerlein ◽  
Maria-Helena DiMarino ◽  
Ted Becker ◽  
Peter Johnson
Keyword(s):  
Muscle Activity ◽  
Maximum Voluntary Contraction ◽  
Trapezius Muscle ◽  
Surface Emg ◽  
Voluntary Contraction ◽  
Office Work ◽  
Shoulder Muscle ◽  
Physical Risk Factors ◽  
Computer Workstation ◽  
Muscle Groups

The computer workstation is a ubiquitous tool in the office work environment; however, its use varies across many different tasks from surfing the Internet to typing. The question, therefore, is how does exposure to different physical risk factors for musculoskeletal disorders vary across tasks? Fifteen adults (10 females, 5 males) completed tasks simulating work at a computer workstation. The tasks were typing text, completing an html-based form, editing a document, a graphics task, and finally navigating through a series of web pages. During these tasks the muscle activity of the wrist prime movers and three shoulder muscle groups were recorded using surface EMG. For the wrist, the extensors were the most active ranging on average from 8 to 25 percent of Maximum Voluntary Contraction amplitude, with the greatest activity occurring in the typing task. The wrist activity decreased when the work changed from a keyboard-based activity to predominantly mouse-based activity. For the shoulder, the greatest activity was in the Trapezius muscle. The shoulder muscles were most active when both the mouse and the keyboard were required by the task. in summary, wrist and shoulder muscle activities at a computer workstation depend upon the type of task at hand.

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