scholarly journals Upper extremity biomechanics in native and non-native signers

Work ◽  
2021 ◽  
pp. 1-9
Author(s):  
Gretchen Roman ◽  
Daniel S. Peterson ◽  
Edward Ofori ◽  
Meghan E. Vidt
Keyword(s):  
Upper Extremity ◽  
Injury Risk ◽  
Muscle Activation ◽  
Joint Angle ◽  
Wrist Flexion ◽  
Upper Trapezius ◽  
Flexion Extension ◽  
Deaf Parents ◽  
Native Signers ◽  
Anterior Posterior

BACKGROUND: Individuals fluent in sign language (signers) born to non-signing, non-deaf parents (non-natives) may have a greater injury risk than signers born to signing, deaf parents (natives). A comprehensive analysis of movement while signing in natives and non-natives has not been completed and could provide insight into the greater injury prevalence of non-natives. OBJECTIVE: The objective of this study was to determine differences in upper extremity biomechanics between non-natives and natives. METHODS: Strength, ‘micro’ rests, muscle activation, ballistic signing, joint angle, and work envelope were captured across groups. RESULTS: Non-natives had fewer rests (p = 0.002) and greater activation (p = 0.008) in non-dominant upper trapezius. For ballistic signing, natives had greater anterior-posterior jerk (p = 0.033) and for joint angle, natives demonstrated greater wrist flexion-extension range of motion (p = 0.040). Natives also demonstrated greater maximum medial-lateral (p = 0.015), and greater minimum medial-lateral (p = 0.019) and superior-inferior (p = 0.027) positions. CONCLUSIONS: We observed that natives presented with more rests and less activation, but greater ballistic tendencies, joint angle, and envelope compared to non-natives. Additional work should explore potential links between these outcomes and injury risk in signers.

Arm Posture and Muscular Activity while Inserting and Aiming with Laparoscopic Tools

2005 ◽  
Vol 49 (14) ◽  
pp. 1399-1403
Author(s):  
Trejo, A.E. Jung ◽  
M.S. Hallbeck
Keyword(s):  
Biceps Brachii ◽  
Muscular Activity ◽  
Elbow Flexion ◽  
Dominant Hand ◽  
Wrist Flexion ◽  
Triceps Brachii ◽  
Upper Trapezius ◽  
Flexion Extension ◽  
Laparoscopic Tools ◽  
Wrist Flexors

Two laparoscopic tools, a scissor-type grasper and an ergonomically designed grasper, were compared in terms of arm posture and muscle activity during insertion into a trocar and during a standardized aiming task. Participants were asked to insert a laparoscopic tool into a simulated abdomen and hit five cross-shaped targets using their dominant hand; similar to reaching an organ during laparoscopic surgery. Twenty-six right-handed novice participants volunteered for the study. Two electrogoniometers were used to measure wrist flexion/extension, wrist deviation, and elbow flexion/extension angles. Six surface electrodes were used to measure %MVE of wrist flexors, wrist extensors, biceps brachii, triceps brachii, deltoid, and upper trapezius. The conditions used were five target positions, two touch screen monitor angles, and five hand postures. The scissors-type tool caused the largest wrist flexion, but the smallest %MVE from the wrist flexors. The method of gripping the tools was the most important factor determining joint angles and muscular load during the insertion and aiming tasks.

Cutting Force and EMG Recordings for Ergonomics Assessment of Meat Cutting Tasks: Influence of the Workbench Height and the Cutting Direction on Muscle Activation Levels

2012 ◽  
Author(s):  
Charles Pontonnier ◽  
Georges Dumont ◽  
Mark de Zee ◽  
Afshin Samani ◽  
Pascal Madeleine
Keyword(s):  
Upper Extremity ◽  
Muscle Activation ◽  
Biceps Brachii ◽  
Control Strategies ◽  
Arm Movement ◽  
Design Parameters ◽  
Assessment Protocol ◽  
Upper Trapezius ◽  
Long Head ◽  
Cutting Direction

Repetitive arm movement and force exertion are common in meat cutting tasks and often lead to musculosketal disorders. In this study, the effects of the workbench height and the cutting direction on the levels of muscular activation of the upper extremity during meat cutting tasks were investigated. Seven subjects performed 4 trials of 20s each at the 4 different heights (0 cm, −10 cm, −20 cm and −30 cm below the elbow height), alternating two cutting directions. Activation levels of upper extremity muscles (biceps brachii, triceps long head, deltoideus anterior, deltoideus medialis and upper trapezius) and cutting forces were recorded synchronously. Then the trends of the normalized activations with regard to the workplace design parameters (table height and cutting direction) were computed. Results showed that the optimal configuration is a partially related to the task, whereas motor control strategies have also an influence on it. The present results provide new key information about the effects of workbench heights during a repetitive meat cutting task and a complete assessment protocol to analyse workstation design parameters influence on muscles activation levels.

Upper Extremity Kinetics in Poultry Processing: A Comparison between Two Different Cutting Tasks

2003 ◽  
Vol 19 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Dwight E. Waddell ◽  
Craig Wyvill ◽  
Robert J. Gregor
Keyword(s):  
Risk Factors ◽  
Upper Extremity ◽  
Assessment System ◽  
Emg Activity ◽  
Wrist Flexion ◽  
External Work ◽  
Factors Associated ◽  
Flexion Extension ◽  
Poultry Processing ◽  
Trauma Disorders

A field study was performed using a new data collection system looking at upper extremity kinetics during two different cutting tasks, wing vs. tender cuts, in three poultry plants. The Ergonomic Work Assessment System (EWAS) was designed to simultaneously record knife forces (Fx, Fy, and Fz), electromyographic (EMG) activity (forearm flexors/extensors), and goniometric data (wrist flexion/extension), all of which may represent risk factors associated with cumulative trauma disorders, specifically carpal tunnel syndrome (CTS). The objective of this study was to monitor workers in an unencumbered fashion as they performed two different poultry cutting tasks. It was assumed that the variables measured by EWAS would be able to discriminate between the two cuts and quantify possible differences between the two. The results confirmed that EWAS successfully showed significant differences in knife forces between the wing and tender cuts. Knife force differences were also observed between plants for the same cut. Differences in the two cuts were also identified in the EMG and wrist angles. EWAS successfully quantified variables that may represent risk factors associated with CTS in three poultry plants. Knowledge of a better quantitatively described external work environment may enable plants to better design rotation schedules for their deboners.

scholarly journals Swimming Practice and Scapular Kinematics, Scapulothoracic Muscle Activity, and the Pressure-Pain Threshold in Young Swimmers

2018 ◽  
Vol 53 (11) ◽  
pp. 1056-1062
Author(s):  
Fernanda A. P. Habechian ◽  
Ana Letícia Lozana ◽  
Ann M. Cools ◽  
Paula R. Camargo
Keyword(s):  
Upper Extremity ◽  
Analysis Of Variance ◽  
Muscle Activity ◽  
Pain Sensitivity ◽  
Muscle Activation ◽  
Pain Threshold ◽  
Pressure Pain Threshold ◽  
Scapular Kinematics ◽  
Upper Trapezius ◽  
Competitive Swimmers

Context Whereas alterations in scapular kinematics, scapulothoracic muscle activity, and pain sensitivity have been described in adult swimmers, no researchers have examined these outcomes in young swimmers. Objectives To compare scapular kinematics, scapulothoracic muscle activation, and the pressure-pain threshold (PPT) of the shoulder muscles among young nonpractitioners (those who were not involved in sports involving the upper limbs), amateur swimmers, and competitive swimmers. Design Cross-sectional study. Setting Laboratory. Patients or Other Participants A total of 90 individuals (age = 11.63 ± 0.61 years) in 3 groups: nonpractitioners, amateur swimmers, and competitive swimmers. Intervention(s) Scapular kinematics and activity of the upper trapezius, lower trapezius, and serratus anterior (SA) were measured during upper extremity elevation in the scapular plane. The PPT was assessed in the upper trapezius, infraspinatus, supraspinatus, middle deltoid, and tibialis anterior. Main Outcome Measure(s) Scapular kinematics, scapulothoracic muscle activation, and PPT. We conducted a 2-way mixed-model analysis of variance and a 1-way analysis of variance for scapular rotation and PPT, respectively. A Kruskal-Wallis test was used to assess muscle activity. The α level was set at .05. Results Competitive swimmers presented more internal rotation at 90° (P = .03) and 120° (P = .047) and more anterior tilt at 90° (P = .03) than nonpractitioners. Amateur swimmers demonstrated more anterior tilt at 90° (P = .004) and 120° (P = .005) than nonpractitioners. Competitive swimmers had greater SA activation in the intervals from 60° to 90° (P = .02) and 90° to 120° (P = .01) than amateur swimmers. They also displayed more SA activation in the interval from 90° to 120° than nonpractitioners (P = .04). No differences were found in any of the muscles for the PPT (P > .05). Conclusions Young competitive swimmers presented alterations in scapular kinematics and scapulothoracic muscle activation during upper extremity elevation that may be due to sport practice. Mechanical pain sensitivity was not altered in young swimmers.

scholarly journals Design and Development of Continuous Passive Motion (CPM) for Fingers and Wrist Grounded-Exoskeleton Rehabilitation System

2021 ◽  
Vol 11 (2) ◽  
pp. 815
Author(s):  
Husam Almusawi ◽  
Géza Husi
Keyword(s):  
Experimental Testing ◽  
Hand Movement ◽  
Evaluation Process ◽  
Continuous Passive Motion ◽  
Wrist Flexion ◽  
Design And Development ◽  
Passive Motion ◽  
Assistive Robots ◽  
Flexion Extension ◽  
Design Characteristics

Impairments of fingers, wrist, and hand forearm result in significant hand movement deficiencies and daily task performance. Most of the existing rehabilitation assistive robots mainly focus on either the wrist training or fingers, and they are limiting the natural motion; many mechanical parts associated with the patient’s arms, heavy and expensive. This paper presented the design and development of a new, cost-efficient Finger and wrist rehabilitation mechatronics system (FWRMS) suitable for either hand right or left. The proposed machine aimed to present a solution to guide individuals with severe difficulties in their everyday routines for people suffering from a stroke or other motor diseases by actuating seven joints motions and providing them repeatable Continuous Passive Motion (CPM). FWRMS approach uses a combination of; grounded-exoskeleton structure to provide the desired displacement to the hand’s four fingers flexion/extension (F/E) driven by an indirect feed drive mechanism by adopting a leading screw and nut transmission; and an end-effector structure to provide angular velocity to the wrist flexion/ extension (F/E), wrist radial/ulnar deviation (R/U), and forearm supination/pronation (S/P) driven by a rotational motion mechanism. We employed a single dual-sided actuator to power both mechanisms. Additionally, this article presents the implementation of a portable embedded controller. Moreover, this paper addressed preliminary experimental testing and evaluation process. The conducted test results of the FWRMS robot achieved the required design characteristics and executed the motion needed for the continuous passive motion rehabilitation and provide stable trajectories guidance by following the natural range of motion (ROM) and a functional workspace of the targeted joints comfortably for all trainable movements by FWRMS.

scholarly journals Joint-Specific Play Controller for Upper Extremity Therapy: Feasibility Study in Children With Wrist Impairment

2016 ◽  
Vol 96 (11) ◽  
pp. 1773-1781
Author(s):  
Bethany J. Wilcox ◽  
Megan M. Wilkins ◽  
Benjamin Basseches ◽  
Joel B. Schwartz ◽  
Karen Kerman ◽  
...  
Keyword(s):  
Upper Extremity ◽  
Computer Games ◽  
Average Frequency ◽  
Cross Sectional Study ◽  
Wrist Flexion ◽  
Motor Impairments ◽  
Cross Sectional ◽  
Play Activity ◽  
Play Session ◽  
Flexion And Extension

Abstract Background Challenges with any therapeutic program for children include the level of the child's engagement or adherence. Capitalizing on one of the primary learning avenues of children, play, the approach described in this article is to develop therapeutic toy and game controllers that require specific and repetitive joint movements to trigger toy/game activation. Objective The goal of this study was to evaluate a specially designed wrist flexion and extension play controller in a cohort of children with upper extremity motor impairments (UEMIs). The aim was to understand the relationship among controller play activity, measures of wrist and forearm range of motion (ROM) and spasticity, and ratings of fun and difficulty. Design This was a cross-sectional study of 21 children (12 male, 9 female; 4–12 years of age) with UEMIs. Methods All children participated in a structured in-clinic play session during which measurements of spasticity and ROM were collected. The children were fitted with the controller and played with 2 toys and 2 computer games for 5 minutes each. Wrist flexion and extension motion during play was recorded and analyzed. In addition, children rated the fun and difficulty of play. Results Flexion and extension goal movements were repeatedly achieved by children during the play session at an average frequency of 0.27 Hz. At this frequency, 15 minutes of play per day would result in approximately 1,700 targeted joint motions per week. Play activity was associated with ROM measures, specifically supination, but toy perception ratings of enjoyment and difficulty were not correlated with clinical measures. Limitations The reported results may not be representative of children with more severe UEMIs. Conclusions These outcomes indicate that the therapeutic controllers elicited repetitive goal movements and were adaptable, enjoyable, and challenging for children of varying ages and UEMIs.

scholarly journals Elbow Joint Fatigue and Bench-Press Training

2014 ◽  
Vol 49 (3) ◽  
pp. 317-321 ◽  
Author(s):  
Yen-Po Huang ◽  
You-Li Chou ◽  
Feng-Chun Chen ◽  
Rong-Tyai Wang ◽  
Ming-Jer Huang ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Upper Extremity ◽  
Athletic Training ◽  
Cycle Time ◽  
Elbow Joint ◽  
Muscle Activation ◽  
Bench Press ◽  
Lateral Force ◽  
Joint Force ◽  
Muscle Strengthening

Context: Bench-press exercises are among the most common form of training exercise for the upper extremity because they yield a notable improvement in both muscle strength and muscle endurance. The literature contains various investigations into the effects of different bench-press positions on the degree of muscle activation. However, the effects of fatigue on the muscular performance and kinetics of the elbow joint are not understood fully. Objective: To investigate the effects of fatigue on the kinetics and myodynamic performance of the elbow joint in bench-press training. Design: Controlled laboratory study. Setting: Motion research laboratory. Patients or Other Participants: A total of 18 physically healthy male students (age = 19.6 ± 0.8 years, height = 168.7 ± 5.5 cm, mass = 69.6 ± 8.6 kg) participated in the investigation. All participants were right-hand dominant, and none had a history of upper extremity injuries or disorders. Intervention(s): Participants performed bench-press training until fatigued. Main Outcome Measure(s): Maximal possible number of repetitions, cycle time, myodynamic decline rate, elbow-joint force, and elbow-joint moment. Results: We observed a difference in cycle time in the initial (2.1 ± 0.42 seconds) and fatigue (2.58 ± 0.46 seconds) stages of the bench-press exercise (P = .04). As the participants fatigued, we observed an increase in the medial-lateral force (P = .03) and internal-external moment (P ≤ .04) acting on the elbow joint. Moreover, a reduction in the elbow muscle strength was observed in the elbow extension-flexion (P ≤ .003) and forearm supination-pronation (P ≤ .001) conditions. Conclusions: The results suggest that performing bench-press exercises to the point of fatigue increases elbow-joint loading and may further increase the risk of injury. Therefore, when clinicians design bench-press exercise regimens for general athletic training, muscle strengthening, or physical rehabilitation, they should control carefully the maximal number of repetitions.

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