scholarly journals MUSCLE CONTRACTION DURING MANEUVERING STEERING WHEEL USING SURFACE ELECTROMYOGRAPYHY

2020 ◽  
Vol 20 (Special1) ◽  
pp. 216-222
Author(s):  
Darliana M ◽  
Baba MD ◽  
Dian DID ◽  
Ahmad RI
Keyword(s):  
Muscle Contraction ◽  
Biceps Brachii ◽  
Strong Relationship ◽  
Elbow Flexion ◽  
Objective Measurement ◽  
Steering Wheel ◽  
Shoulder Abduction ◽  
Road Accidents ◽  
Driving Posture ◽  
The Right

Driving posture is one of the factors that need to be emphasized in ensuring driver’s comfort and to avoid road accidents and injuries. Meanwhile, fatigue has a strong relationship with comfortable posture and it contributes 15.7% of the total road accidents in Malaysia. Fatigue can reduce driving concentration and performances, thus increases the risk of road accidents and injuries. In order to determine the driver’s comfort, this study had measured muscle contraction using the objective measurement for comfortable and optimum driving posture angles. The equipment used for conducting objective measurement on 14 respondents was sEMG. The researcher had used sEMG equipment to evaluate muscles activities at upper extremities, which comprises of Biceps Brachii (BB), Deltoid Anterior (DA) and Trapezious Upper (TU) that were involved during controlling the car steering. It involves three driving postures parameters according to the fixed elbow and shoulder angles. The results from this study showed the BB muscle increased positively when turning the steering wheel to the right within 3 to 6 times value increased. Meanwhile, DA and TU muscles experience a contraction in the opposite direction with steering wheel turning action, which shows higher right side DA and TU muscle contraction when the driver turn the steering to the left with around 80% decrease for DA and within 60% to 80% decrease value for TU. BB muscle also shows an increasing value of muscle contraction with higher elbow flexion, meanwhile DA and TU muscles contraction also show an increment in-line with greater shoulder abduction. The results showed that posture B with elbow angle at 36° and shoulder angle at 134° are the most comfortable driving postures, hence the lowest muscle contraction value of 15.67μV (BB), 19.31μV (DA) and 12.36μV (TU) compared to the other two measured postures. The results of muscle contraction from this study is capable of assisting researchers and car manufacturers to understand the relationship of steering maneuvering when developing more comfortable and suitable vehicle’s driver seat compartment.

639 Maximizing Safe Positioning of Upper Extremities after Axillary Burn Injuries to Prevent Contractures and Maintain Function

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S175-S176
Author(s):  
Connie Greiser ◽  
David Lorello ◽  
Dan Lyons ◽  
Karen J Richey ◽  
Derek Murray ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Elbow Flexion ◽  
Primary Objective ◽  
Burn Injuries ◽  
Shoulder Abduction ◽  
Shoulder Injury ◽  
Shoulder Range Of Motion ◽  
History Of ◽  
The Right ◽  
Shoulder Range

Abstract Introduction Burns crossing over a joint can result in a contracture of that joint. Axillary burns and subsequent contractures are common and may impact negatively on burn survivor rehabilitation. Positioning of burned extremities at the most lengthened position is ideal for maintenance of function and contracture prevention, 90 degrees of abduction is the most accepted position for axillary burn injuries. However, many activities of daily living require shoulder range of motion (ROM) greater than 90 degrees. The primary objective of this study was to describe and examine the incidence of paresthesia, pain, and intolerance in healthy subjects when the shoulder was placed in a position of 90 degrees or greater of shoulder abduction. Methods The subject’s nondominant upper extremity (NDE) was randomly placed in a series three of positions, including: (1) 90 degrees shoulder abduction, 30 degrees horizontal adduction with elbow extension, forearm neutral; (2) 130 degrees shoulder abduction, 30 degrees horizontal adduction, 30 degrees elbow flexion, forearm neutral; (3) 150 degrees shoulder abduction, 30 degrees horizontal adduction, 30 degrees elbow flexion, forearm neutral. Each position was maintained for a maximum of 2 hours. Subjects experiencing subjective symptoms including paresthesia lasting longer than 1 minute, pain rated greater than 3/10, and/or intolerance 2/5 was removed from the position. All subjects received at least 30 minutes of rest between positions. Results A total of 25 subjects were enrolled, mean age was 25.8 years, the majority were female (60%) and 20% had a history of NDE shoulder injury. The right arm was the dominant extremity (DE) in 88% of subjects. There were no significant differences in ROM between the DE and NDE extremity with the exception of external shoulder rotation, 94.96⁰ vs 84.8⁰ (p=.0142). Average total splint time was 136 minutes with a range of 40 – 360 minutes. Only 1 subject successfully completed all 3 splinting periods. There were 75 individual splinting events over the 3 splinting periods, and 90% of the time the splinting was stopped early. The most common reason for stopping early was paresthesia (88%) followed by pain (7%). Conclusions The positions selected represent the routine and usual care at our burn center. Patients are routinely positioned from hours to days depending on patient need. This study demonstrated that healthy subjects were unable to tolerate positioning for even two hours.

Electromyographic and Systemic Physiological Thresholds in Single-Joint Elbow Flexion Movements

2021 ◽  
pp. 1-8
Author(s):  
Markus Tilp ◽  
Lukas Kitzberger ◽  
Gudrun Schappacher-Tilp ◽  
Philipp Birnbaumer ◽  
Peter Hofmann
Keyword(s):  
Heart Rate ◽  
Biceps Brachii ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Strong Relationship ◽  
Elbow Flexion ◽  
Whole Body ◽  
Specific Information ◽  
Maximum Weight ◽  
Close Relationship

Purpose: Reported relationships between electromyographic (EMG) thresholds and systemic thresholds based on lactate, ventilation, or heart rate are contradictory. This might be related to the complexity of the investigated whole-body movements involving many muscles with different activation patterns. Therefore, the aim of the study was to investigate these relationships during an incremental single-joint exercise. Methods: Eighteen male subjects (29.7 [4.4] y) performed single-arm elbow flexions on a biceps curl machine with loads increasing every minute until exhaustion. EMG signals of the main elbow flexors (short and long head of the biceps brachii, flexor carpi radialis, and brachioradialis) as well as gas exchange variables, blood lactate concentration, and heart rate were measured, and 2 turn points based on a 3-phase model of metabolism were determined for each variable. Results: The first and second turn points for EMG were determined at 32.0% to 33.1% and 64.4% to 66.5% of maximal achieved performance (maximum weight), respectively. Systemic turn points were determined at 33.3% to 34.4% and 65.9% to 66.7% of maximum weight and were not significantly different from EMG turn points. Furthermore, systemic and EMG turn points showed a strong or very strong relationship at the first (ρ = .54–.93, P < .05) and second turn point (ρ = .76–.93, P < .01). Conclusions: A close relationship between EMG and systemic turn points could be confirmed for the applied movement of a small muscle group. The determination of local single muscle thresholds using EMG provides additional muscle-specific information about performance-limiting properties of muscles involved in endurance-type incremental exercise.

Sequence of Preparatory Set for Response Movement

1988 ◽  
Vol 66 (2) ◽  
pp. 515-520 ◽  
Author(s):  
Takashi Kinugasa ◽  
Keisuke Fukuda ◽  
Ryuichi Nakamura ◽  
Toru Hosokawa
Keyword(s):  
Biceps Brachii ◽  
Reaction Times ◽  
Movement Patterns ◽  
Warning Signal ◽  
Elbow Flexion ◽  
Preparatory Set ◽  
The Subject ◽  
The Difference ◽  
The Right ◽  
Simple Rt

Electromyographic reaction times (EMG-RTs) of the right biceps brachii muscle were examined for two movement patterns, elbow flexion and forearm supination, in 8 healthy male subjects under simple and complex RT conditions with varied preparatory intervals (PIs): 0, 200, 400, 600, and 800 msec. In the simple RT condition, the subject was informed of the movement patterns to be performed prior to beginning the trials. In the complex RT condition the subject had to choose one of the two movement patterns at the time of the presentation of a warning signal. The results indicated that: (1) compared with the simple RT condition a delay of about 100 msec. in over-all mean EMG-RT was observed at PI = 0 msec. in the complex RT condition; (2) the difference of over-all mean EMG-RT between the two RT conditions disappeared when PI = 400 msec.; and (3) the difference in EMG-RTs between flexion and supination in the complex RT condition became the same as that in the simple RT condition when PI = 700 msec. It is assumed that the preparatory set for response movements is organized in an order, resulting in the differentiation of RT.

In Vivo Measurements of Moment Arm Lengths of Three Elbow Flexors at Rest and During Isometric Contractions

2012 ◽  
Vol 28 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Ryota Akagi ◽  
Soichiro Iwanuma ◽  
Satoru Hashizume ◽  
Hiroaki Kanehisa ◽  
Toshimasa Yanai ◽  
...  
Keyword(s):  
Biceps Brachii ◽  
Elbow Flexion ◽  
Isometric Contractions ◽  
Elbow Flexors ◽  
Moment Arm ◽  
Resonance Imaging ◽  
Intensity Dependence ◽  
In Vivo Measurements ◽  
The Right

The purpose of this study was to determine in vivo moment arm lengths (MAs) of three elbow flexors at rest and during low- and relatively high-intensity contractions, and to examine the contraction intensity dependence of MAs at different joint positions. At 50°, 80° and 110° of elbow flexion, MAs of the biceps brachii, brachialis and brachioradialis were measured in 10 young men using sagittal images of the right arm obtained by magnetic resonance imaging, at rest and during 20% and 60% of isometric maximal voluntary elbow flexion. In most conditions, MAs increased with isometric contractions, which is presumably due to the contraction-induced thickening of the muscles. This phenomenon was especially evident in the flexed elbow positions. The influence of the contraction intensities on the increases in MAs varied across the muscles. These results suggest that in vivo measurements of each elbow flexor MA during contractions are essential to properly examine the effects on the interrelationships between elbow flexion torque and individual muscle forces.

scholarly journals Covid-19 Brachial plexopathy: a case report

2021 ◽  
Author(s):  
Antonio Edvan Camelo Filho ◽  
Diego Sant’Ana Sodré ◽  
Halisson Flamini Arantes ◽  
Carlos Otto Heise
Keyword(s):  
Case Report ◽  
Neuronal Damage ◽  
Elbow Flexion ◽  
Point Of View ◽  
Shoulder Abduction ◽  
Brachial Plexopathy ◽  
Cross Sectional ◽  
Electrophysiological Characterization ◽  
The Right

Context: The understanding of neuromuscular manifestations secondary to infection by SARS-CoV-2 is scarce. Peripheral neuropathies are a heterogeneous group of diseases affecting the peripheral nervous system, with a variable motor, sensitive and autonomic involvement. There are recent descriptions of atypical patterns of neuropathies after COVID-19. In this study we aim to report a brachial plexopathy secondary to COVID-19 with its clinical and electrophysiological characterization. We performed a cross-sectional, observational, descriptive, case report type, using medical record review. Case report: A 42 year-old female was hospitalized for 2 months due to severe respiratory syndrome due to COVID-19. She remained in the ICU for 20 days. During her stay in the ward she complained of weakness and pain in his right upper limb. Physical examination revealed weakness in the right shoulder abduction and elbow flexion. Nerve conduction studies demonstrated involvement of the upper trunk of the right brachial plexus. There was no report of trauma. Her BMI was 50 kg/m2. Conclusions: Recent studies bring atypical descriptions of focal neuropathies, multiple mononeuropathies and plexopathies, opening a new field of study in addition to the description of neuromuscular weakness following ICU stay after COVID-19. From an electrophysiological point of view, there is a recent interest in better characterization of patients with axonal neuropathies suggesting a possible vasculitic mechanism of neuronal damage after COVID-19. Further investigations are necessary to improve the characterization of this particular group, helping its diagnosis and early treatment to reduce complications and disabilities.

scholarly journals Dynamic Analysis of the Abnormal Isometric Strength Movement Pattern between Shoulder and Elbow Joint in Patients with Hemiplegia

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Yali Liu ◽  
Yuezhen Hong ◽  
Linhong Ji
Keyword(s):  
Elbow Joint ◽  
Biceps Brachii ◽  
Movement Pattern ◽  
Elbow Flexion ◽  
Shoulder Abduction ◽  
Triceps Brachii ◽  
Stereotyped Movement ◽  
Weak Muscle ◽  
Antagonistic Muscles ◽  
Voluntary Strength

Patients with hemiplegia usually have weak muscle selectivity and usually perform strength at a secondary joint (secondary strength) during performing a strength at one joint (primary strength). The abnormal strength pattern between shoulder and elbow joint has been analyzed by the maximum value while the performing process with strength changing from 0 to maximum then to 0 was a dynamic process. The objective of this study was to develop a method to dynamically analyze the strength changing process. Ten patients were asked to perform four group asks (maximum and 50% maximum voluntary strength in shoulder abduction, shoulder adduction, elbow flexion, and elbow extension). Strength and activities from seven muscles were measured. The changes of secondary strength had significant correlation with those of primary strength in all tasks (R>0.76, p<0.01). The antagonistic muscles were moderately influenced by the primary strength (R>0.4, p<0.01). Deltoid muscles, biceps brachii, triceps brachii, and brachioradialis had significant influences on the abnormal strength pattern (all p<0.01). The dynamic method was proved to be efficient to analyze the different influences of muscles on the abnormal strength pattern. The muscles, deltoid muscles, biceps brachii, triceps brachii, and brachioradialis, much influenced the stereotyped movement pattern between shoulder and elbow joint.

79 Maximizing Safe Positioning of Upper Extremities After Axillary Burn Injuries to Prevent Contractures and Maintain Function

2020 ◽  
Vol 41 (Supplement_1) ◽  
pp. S51-S51
Author(s):  
Connie Greiser ◽  
David Lorello ◽  
Eric Barto ◽  
S V Gartner ◽  
Dan Lyons ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Elbow Flexion ◽  
Primary Objective ◽  
Burn Injuries ◽  
Shoulder Abduction ◽  
Shoulder Injury ◽  
Shoulder Range Of Motion ◽  
History Of ◽  
The Right ◽  
Shoulder Range

Abstract Introduction Burns crossing over a joint can result in a contracture of that joint. Axillary burns and subsequent contractures are common and may impact negatively on burn survivor rehabilitation. Positioning of burned extremities at the most lengthened position is ideal for maintenance of function and contracture prevention, 90 degrees of abduction is the most accepted position for axillary burn injuries. However, many activities of daily living require shoulder range of motion (ROM) greater than 90 degrees. The primary objective of this study was to describe and examine the incidence of paresthesia, pain, and intolerance in healthy subjects when the shoulder was placed in a position of 90 degrees or greater of shoulder abduction. Methods The subject’s nondominant upper extremity (NDE) was randomly placed in a series three of positions, including: (1) 90 degrees shoulder abduction, 30 degrees horizontal adduction with elbow extension, forearm neutral; (2) 130 degrees shoulder abduction, 30 degrees horizontal adduction, 30 degrees elbow flexion, forearm neutral; (3) 150 degrees shoulder abduction, 30 degrees horizontal adduction, 30 degrees elbow flexion, forearm neutral. Each position was maintained for a maximum of 2 hours. Subjects experiencing subjective symptoms including paresthesia lasting longer than 1 minute, pain rated greater than 3/10, and/or intolerance 2/5 was removed from the position. All subjects received at least 30 minutes of rest between positions. Results A total of 25 subjects were enrolled, mean age was 25.8 years, the majority were female (60%) and 20% had a history of NDE shoulder injury. The right arm was the dominant extremity (DE) in 88% of subjects. There were no significant differences in ROM between the DE and NDE extremity with the exception of external shoulder rotation, 94.96⁰ vs 84.8⁰ (p=.0142). Average total splint time was 136 minutes with a range of 40 – 360 minutes. Only 1 subject successfully completed all 3 splinting periods. There were 75 individual splinting events over the 3 splinting periods, and 90% of the time the splinting was stopped early. The most common reason for stopping early was paresthesia (88%) followed by pain (7%). Conclusions The positions selected represent the routine and usual care at our burn center. Patients are routinely positioned from hours to days depending on patient need. This study demonstrated that healthy subjects were unable to tolerate positioning for even two hours. Applicability of Research to Practice Additional research is needed to determine optimal positioning for the shoulder joint.

Objective Measurement of Sustained Pupillary Constriction: A Pilot Study Using an App-Based Pupilometer

2020 ◽  
pp. 57-63
Keyword(s):  
Ganglion Cells ◽  
Modern Technology ◽  
Objective Measurement ◽  
Retinal Ganglion ◽  
Case Examples ◽  
Pupillary Reaction ◽  
Sympathetic Nervous Systems ◽  
Pupillary Constriction ◽  
The Individual ◽  
The Right

Background: The pupillary reaction is controlled by the two main branches of the autonomic nervous system, namely the parasympathetic and sympathetic nervous systems. New discoveries in pupil research has identified that intrinsically photosensitive retinal ganglion cells have an impact on pupillary constriction, particularly sustained pupillary constriction. In the current paper, an objective measurement of sustained pupillary constriction versus the inability to maintain sustained pupillary constriction are observed. The variability in the sustained pupillary constriction, i.e. Alpha Omega pupil, can be objectively identified with the use of modern technology. Case Examples: Two female subjects were adapted to dim illumination, and then two objective pupil measurements of the right eye using Reflex – PLR Analyzer by BrightLamp© (Indianapolis, IN, USA) with sustained illumination were obtained. Subject 1, a 25 year-old-female, demonstrated normal ability of the pupil to constrict and sustain constriction for 10 seconds. She was used as a control for subject 2. Subject 2, a 27 year-old-female, demonstrated the inability to sustain pupillary constriction. She reported being under great psychological stress. Her pupil began to re-dilate between 2 and 3 seconds after the initial constriction. Conclusion: Objective pupillometry can be used to assist in many diagnoses and provides the clinician invaluable information on the state of the individual, and qualifications of sustained pupillary constriction can now be assessed in an objective manner.

Analysis of human acellular nerve allograft combined with contralateral C7 nerve root transfer for restoration of shoulder abduction and elbow flexion in brachial plexus injury: a mean 4-year follow-up

2020 ◽  
Vol 132 (6) ◽  
pp. 1914-1924 ◽  
Author(s):  
Liang Li ◽  
Jiantao Yang ◽  
Bengang Qin ◽  
Honggang Wang ◽  
Yi Yang ◽  
...  
Keyword(s):  
Brachial Plexus ◽  
Nerve Root ◽  
Functional Outcomes ◽  
Elbow Flexion ◽  
Shoulder Abduction ◽  
Allograft Reconstruction ◽  
Acellular Nerve Allograft ◽  
The Mean ◽  
Monofilament Test

OBJECTIVEHuman acellular nerve allograft applications have increased in clinical practice, but no studies have quantified their influence on reconstruction outcomes for high-level, greater, and mixed nerves, especially the brachial plexus. The authors investigated the functional outcomes of human acellular nerve allograft reconstruction for nerve gaps in patients with brachial plexus injury (BPI) undergoing contralateral C7 (CC7) nerve root transfer to innervate the upper trunk, and they determined the independent predictors of recovery in shoulder abduction and elbow flexion.METHODSForty-five patients with partial or total BPI were eligible for this retrospective study after CC7 nerve root transfer to the upper trunk using human acellular nerve allografts. Deltoid and biceps muscle strength, degree of shoulder abduction and elbow flexion, Semmes-Weinstein monofilament test, and static two-point discrimination (S2PD) were examined according to the modified British Medical Research Council (mBMRC) scoring system, and disabilities of the arm, shoulder, and hand (DASH) were scored to establish the function of the affected upper limb. Meaningful recovery was defined as grades of M3–M5 or S3–S4 based on the scoring system. Subgroup analysis and univariate and multivariate logistic regression analyses were conducted to identify predictors of human acellular nerve allograft reconstruction.RESULTSThe mean follow-up duration and the mean human acellular nerve allograft length were 48.1 ± 10.1 months and 30.9 ± 5.9 mm, respectively. Deltoid and biceps muscle strength was grade M4 or M3 in 71.1% and 60.0% of patients. Patients in the following groups achieved a higher rate of meaningful recovery in deltoid and biceps strength, as well as lower DASH scores (p < 0.01): age < 20 years and age 20–29 years; allograft lengths ≤ 30 mm; and patients in whom the interval between injury and surgery was < 90 days. The meaningful sensory recovery rate was approximately 70% in the Semmes-Weinstein monofilament test and S2PD. According to univariate and multivariate logistic regression analyses, age, interval between injury and surgery, and allograft length significantly influenced functional outcomes.CONCLUSIONSHuman acellular nerve allografts offered safe reconstruction for 20- to 50-mm nerve gaps in procedures for CC7 nerve root transfer to repair the upper trunk after BPI. The group in which allograft lengths were ≤ 30 mm achieved better functional outcome than others, and the recommended length of allograft in this procedure was less than 30 mm. Age, interval between injury and surgery, and allograft length were independent predictors of functional outcomes after human acellular nerve allograft reconstruction.

scholarly journals Two muscular variations in the elbow associated with the anterior interosseous nerve

2021 ◽  
Author(s):  
Łukasz Olewnik ◽  
Bartłomiej Szewczyk ◽  
Nicol Zielinska ◽  
Dariusz Grzelecki ◽  
Michał Polguj
Keyword(s):  
Biceps Brachii ◽  
Clinical Importance ◽  
Ulnar Artery ◽  
Flexor Pollicis Longus ◽  
Main Band ◽  
Anatomical Dissection ◽  
Pronator Teres ◽  
Anterior Interosseous Nerve ◽  
Male Cadaver ◽  
The Right

AbstractThe coexistence of different muscular-neurovascular variations is of significant clinical importance. A male cadaver, 76 years old at death, was subjected to routine anatomical dissection; the procedure was performed for research and teaching purposes at the Department of Anatomical Dissection and Donation, Medical University of Lodz. The right forearm and hand were dissected using standard techniques according to a strictly specified protocol. The presence accessory head of the flexor pollicis longus may potentially compress the anterior interosseous nerve. The present case report describes a rare variant of the ulnar head of the pronator teres, characterized by two independent bands (i.e., two proximal attachments). The main band originates from the coronoid process and the second originates from the tendon of the biceps brachii. This type of attachment could potentially affect the compression of the ulnar artery running between the two bands. Additionally, the accessory head of the flexor pollicis longus was observed, which started on the medial epicondyle; its coexistence with a high division median nerve creates a potential pressure site on the anterior interesosseous nerve.

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