scholarly journals Usefulness of Scissors with a Power-Support Mechanism to Assist Thumb Movement: An Observational Study

2021 ◽  
Vol 11 (16) ◽  
pp. 7756
Author(s):  
Kohei Koizumi ◽  
Kumiko Sasao ◽  
Yuji Koike ◽  
Akihisa Okino ◽  
Kazuhisa Takeda ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Reference Value ◽  
Thenar Eminence ◽  
Myoelectric Activity ◽  
Eligibility Criteria ◽  
Adductor Pollicis Muscle ◽  
Support Mechanism ◽  
Thumb Movement ◽  
Support Device ◽  
Opening And Closing

Long-term repetitive movements, such as opening and closing scissors, increase strain on muscles and joints. Amplitude probability distribution function (APDF) analysis of surface electromyogram (sEMG) data was used to quantify the burden of muscle activity. We aimed to test the hypothesis that scissors with a power-support device assist repetitive thumb movements to reduce potential myoelectric activity. Twenty female university students who met the eligibility criteria performed a cutting experiment, with and without power-support device scissors. The primary outcome was a change in muscle load due to sEMG data that were analyzed using APDF, and the secondary outcomes investigated the occurrence of muscle fatigue and pain. The adductor pollicis muscle showed a significant decrease in muscle activity with power assistance. In addition, it was also found that fatigue and pain of the thumb and on the radial side of the forearm were significantly lower under the power-assisted conditions. The results of this study suggest that the assistive action of scissors with a power-support device compensate for muscle load on the thenar eminence. This may be used as a reference value to prevent the occurrence of hand disorders for hairdressers.

Myoelectric Activity Differences in Three Learning Sessions

2002 ◽  
Vol 16 (2) ◽  
pp. 92-96
Author(s):  
Tiina Ritvanen ◽  
Reijo Koskelo ◽  
Osmo H„nninen
Keyword(s):  
High School Students ◽  
Muscle Activity ◽  
Muscle Tension ◽  
Emg Activity ◽  
Traditional Learning ◽  
Myoelectric Activity ◽  
School Students ◽  
Language Laboratory ◽  
Upper Trapezius ◽  
Muscle Groups

Abstract This study follows muscle activity in three different learning sessions (computer, language laboratory, and normal classroom) while students were studying foreign languages. Myoelectric activity was measured in 21 high school students (10 girls, 11 boys, age range 17-20 years) by surface electromyography (sEMG) from the upper trapezius and frontalis muscles during three 45-min sessions. Root mean square (RMS) average from both investigated muscles was calculated. The EMG activity was highest in both muscle groups in the computer-aided session and lowest in the language laboratory. The girls had higher EMG activity in both investigated muscle groups in all three learning situations. The measured blood pressure was highest at the beginning of the sessions, decreased within 10 min, but increased again toward the end of the sessions. Our results indicate that the use of a computer as a teaching-aid evokes more constant muscle activity than the traditional learning situations. Since muscle tension can have adverse health consequences, more research is needed to determine optimal classroom conditions, especially when technical aids are used in teaching.

Effect of a Lumbar Support Device on Muscle Activity During Abdominal Exercise

1993 ◽  
Vol 7 (4) ◽  
pp. 219-223
Author(s):  
Mike Ross ◽  
Susan J. Hall ◽  
Nick Breit ◽  
Sam Britten
Keyword(s):  
Muscle Activity ◽  
Lumbar Support ◽  
Support Device

The Mechanical Mechanism of Hulking Force Stable Principle of Surrounding Rocks in Soft Rock Roadway

2014 ◽  
Vol 1065-1069 ◽  
pp. 830-834
Author(s):  
Wei Pei Xue ◽  
Lai Wang Jing
Keyword(s):  
Stress State ◽  
Ultimate Strength ◽  
Soft Rock ◽  
Reference Value ◽  
Industrial Test ◽  
Surrounding Rock ◽  
Support Mechanism ◽  
Rock Creep ◽  
Main Factors

This paper aims to reveal the important role of the hulking force in stabilizing the roadway. After introducing the three ultimate strength of the foundation rock upon, starting from the perspective of stress state, the article on the deformation area surrounding rock for a more reasonable division, and thus gives the main factors roadway deformation.Introduced in the basis of the three ultimate strength of the rock, from the perspective of stress state, deformation of roadway surrounding rock area to carry on the reasonable division, and then the main factors of roadway deformation is presented. Second, through the analysis of the formation of the hulking force, analysis of hulking force inhibition of surrounding rock creep mechanism of dynamic mechanics,and analysis of the hulking force to improve the effect of supporting mechanics mechanism. Describes the important role of the hulking force on the stability of surrounding rock. Finally, Huaibei Coal Mining Co., 8203 guobei roadway industrial test site, Demonstrates the effectiveness of the principle. Results of this study have important reference value to change the current research in deep coal mine deep soft rock and loose seam roadway support mechanism and technology.

scholarly journals The relationship between rowing-related low back pain and rowing biomechanics: a systematic review

2021 ◽  
pp. bjsports-2020-102533
Author(s):  
Frank James Nugent ◽  
Anders Vinther ◽  
Alison McGregor ◽  
Jane S Thornton ◽  
Kellie Wilkie ◽  
...  
Keyword(s):  
Systematic Review ◽  
Low Back Pain ◽  
Back Pain ◽  
Muscle Activity ◽  
Grey Literature ◽  
Low Back ◽  
Eligibility Criteria ◽  
Pelvic Rotation ◽  
Hip Range Of Motion ◽  
Trunk Extensor

BackgroundLow back pain (LBP) is common in rowers. Understanding rowing biomechanics may help facilitate prevention and improve rehabilitation.ObjectivesTo define the kinematics and muscle activity of rowers and to compare with rowers with current or LBP history.DesignSystematic review.Data sourcesEMBASE, MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Web of Science and Scopus from inception to December 2019. Grey literature was searched.Study eligibility criteriaExperimental and non-experimental designs.MethodsPrimary outcomes were kinematics and muscle activity. Modified Quality Index (QI) checklist was used.Results22 studies were included (429 participants). Modified QI score had a mean of 16.7/28 points (range: 15–21). Thirteen studies investigated kinematics and nine investigated muscle activity. Rowers without LBP (‘healthy’) have distinct kinematics (neutral or anterior pelvic rotation at the catch, greater hip range of motion, flatter low back spinal position at the finish) and muscle activity (trunk extensor dominant with less flexor activity). Rowers with LBP had relatively greater posterior pelvic rotation at the catch, greater hip extension at the finish and less efficient trunk muscle activity. In both groups fatigue results in increased lumbar spine flexion at the catch, which is greater on the ergometer. There is insufficient evidence to recommend one ergometer type (fixed vs dynamic) over the other to avoid LBP. Trunk asymmetries are not associated with LBP in rowers.ConclusionImproving clinicians’ and coaches’ understanding of safe and effective rowing biomechanics, particularly of the spine, pelvis and hips may be an important strategy in reducing incidence and burden of LBP.

Head Rotation and Muscle Activity When Conducting Document Editing Tasks with a Head-Mounted Display

2018 ◽  
Vol 62 (1) ◽  
pp. 952-955
Author(s):  
Eunjee Kim ◽  
Gwanseob Shin
Keyword(s):  
Muscle Activity ◽  
Head Rotation ◽  
Myoelectric Activity ◽  
Neck Muscle ◽  
Neck Flexion ◽  
Head Mounted Display ◽  
Shoulder Muscles ◽  
Flexion Moment ◽  
Subjective Discomfort ◽  
Healthy Participants

Potential ergonomic issues associated with the use of a head mounted display (HMD) for office productivity applications have not yet been quantitatively evaluated. A laboratory experiment was conducted to quantitatively evaluate physical stresses and the productivity of the use of HMD. Twenty healthy participants conducted a document editing task for 60 minutes once with an external display and once with a HMD. Head rotation in sagittal and transverse planes, myoelectric activity of neck and shoulder muscles, subjective discomfort ratings and productivity were collected periodically during the task. Results found significantly (p<0.05) greater head rotation movements on both planes, neck muscle activities, and discomfort ratings and decreased productivity when conducting the task with the HMD as compared when using the external display. Difficulty in reading texts due to insufficient resolution of the HMD screen, additional load and neck flexion moment from the weight of the device were responsible for the greater physical stresses associated with the use of HMD.

Evaluation of Driving Fatigue and Change of Muscle Activity During Long-term Driving with Back Support Mechanism Attached

2019 ◽  
Vol 2019 (0) ◽  
pp. 2P1-M10
Author(s):  
Koshiro YAMAMOTO ◽  
Katsuhiro ASANO ◽  
Soichiro HAYAKAWA ◽  
Ryojun IKEURA ◽  
Shigeyoshi TSUTSUMI ◽  
...  
Keyword(s):  
Muscle Activity ◽  
Support Mechanism ◽  
Driving Fatigue

scholarly journals Correspondence between laryngeal vocal fold movement and muscle activity during speech and nonspeech gestures

2004 ◽  
Vol 97 (3) ◽  
pp. 858-866 ◽  
Author(s):  
Christopher J. Poletto ◽  
Laura P. Verdun ◽  
Robert Strominger ◽  
Christy L. Ludlow
Keyword(s):  
Muscle Activity ◽  
Vocal Fold ◽  
Muscle Activation ◽  
Pearson Correlation ◽  
Statistical Significance ◽  
Correlation Coefficients ◽  
Normal Subjects ◽  
Activation Level ◽  
Posterior Cricoarytenoid ◽  
Opening And Closing

To better understand the role of each of the laryngeal muscles in producing vocal fold movement, activation of these muscles was correlated with laryngeal movement during different tasks such as sniff, cough or throat clear, and speech syllable production. Four muscles [the posterior cricoarytenoid, lateral cricoarytenoid, cricothyroid (CT), and thyroarytenoid (TA)] were recorded with bipolar hooked wire electrodes placed bilaterally in four normal subjects. A nasoendoscope was used to record vocal fold movement while simultaneously recording muscle activity. Muscle activation level was correlated with ipsilateral vocal fold angle for vocal fold opening and closing. Pearson correlation coefficients and their statistical significance were computed for each trial. Significant effects of muscle ( P ≤ 0.0005) and task ( P = 0.034) were found on the r (transformed to Fisher's Z′) values. All of the posterior cricoarytenoid recordings related significantly with vocal opening, whereas CT activity was significantly correlated with opening only during sniff. The TA and lateral cricoarytenoid activities were significantly correlated with vocal fold closing during cough. During speech, the CT and TA activity correlated with both opening and closing. Laryngeal muscle patterning to produce vocal fold movement differed across tasks; reciprocal muscle activity only occurred on cough, whereas speech and sniff often involved simultaneous contraction of muscle antagonists. In conclusion, different combinations of muscle activation are used for biomechanical control of vocal fold opening and closing movements during respiratory, airway protection, and speech tasks.

scholarly journals Electromyographic analysis of the suprahyoid muscles in infants based on the lingual fraenulum attachment during breastfeeding

2018 ◽  
Author(s):  
Ellia Christinne de Lima França ◽  
Lucas Carvalho Aragão Albuquerque ◽  
Roberta Castro Lopes Martinelli ◽  
Ilda Machado Fiuza Gonçalves ◽  
Cejana Biocchi Souza ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Muscle Activity ◽  
Reference Value ◽  
Therapeutic Interventions ◽  
Alveolar Ridge ◽  
Term Infants ◽  
Significance Level ◽  
Oral Motor ◽  
Ventral Aspect ◽  
Suprahyoid Muscle

Introduction Muscle electrical activity analysis can aid in the identification of oral motor dysfunctions such as those resulting from altered lingual fraenulum which, in turn, impairs feeding. We aimed to analyse suprahyoid muscle electrical activity of infants based on lingual fraenulum attachment to the sublingual (ventral) aspect of the tongue and floor of the mouth, during breastfeeding. Methods and Results We studied full-term infants of both genders aged between 1–4 months. Lingual fraenulum evaluation and surface suprahyoid muscle electromyography was performed during breastfeeding. Mean muscle activities were recorded in microvolts and converted into percent values (normalisation) of the reference value. Associations between root mean square and independent variables were tested by one-way analysis of variance and Student’s t-test with significance level of 5% and test power of 95%. We evaluated 235 infants while breastfeeding. The lingual fraenulum was commonly attached to the tongue’s ventral aspect between middle third and apex, and on the mouth floor visible from the lower alveolar ridge. Lower muscle activity was observed with lingual fraenulum attached to apex/lower alveolar ridge, followed by attachment to middle third/lower alveolar ridge, and between middle third and apex/lower alveolar ridge. Highest activity observed in Infants with attachment to middle third/sublingual caruncles, had a thin lingual fraenulum, performed several sucks followed by short pauses, showed coordination between swallowing, sucking, and breathing, did not “bite” nipple, and showed no tongue snapping nor stress. Conclusion Greater suprahyoid muscle activity during breastfeeding was observed with lingual fraenulum attachment to middle third of the tongue/sublingual caruncles, showed coordination between swallowing, sucking, and breathing. Surface electromyography is effective in diagnosing lingual fraenulum alterations, whose attachment point raises doubts as restriction of tongue mobility. This technique identifies possible oral motor dysfunctions, enables direct therapeutic interventions and early intervention, and prevents feeding and communication alterations. ²²

Quantitative Intramuscular Myoelectric Activity of Lumbar Portions of Psoas and the Abdominal Wall during Cycling

1998 ◽  
Vol 14 (4) ◽  
pp. 428-438 ◽  
Author(s):  
Daniel Juker ◽  
Stuart McGill ◽  
Peter Kropf
Keyword(s):  
Abdominal Wall ◽  
Muscle Activity ◽  
Activity Patterns ◽  
Rectus Femoris ◽  
Erector Spinae ◽  
Myoelectric Activity ◽  
Standing Up ◽  
Ergometer Cycling ◽  
And Training ◽  
Insight Into

The purpose of this study was to quantify activation using intramuscular EMG from lumbar psoas and the three layers of the abdominal wall during several styles of cycling: normal posture (slightly flexed), upright posture, racing in flexed posture, standing up from the saddle, and standing during maximal sprint effort. Lumbar erector spinae and rectus femoris were also monitored with surface electrodes. Results demonstrated that the activity patterns were influenced by the style of cycling. Furthermore, psoas activity peaked at 14% of MVC (or less) during the upstroke phase of normal cycling but became much more active at TDC during flexed cycling (approximately 30% MVC) and approached 60% of MVC during sprinting. Generally, the abdominal wall was activated to relatively low but continual levels except during standing and sprinting. Erector spinae activity was very low at less than 5% MVC throughout the cycle until standing or sprinting styles were adopted. These normalized and scaled data on deep muscle activity during ergometer cycling provide insight into the functioning of these muscles; this information can be used to prescribe rehabilitation and training programs and can help biomechanists understand muscle activity associated with cycling.

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