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.

Risk factors associated with PICC-related upper extremity venous thrombosis in cancer patients

2013 ◽  
Vol 23 (5-6) ◽  
pp. 837-843 ◽  
Author(s):  
Xiao-lei Yi ◽  
Jie Chen ◽  
Jia Li ◽  
Liang Feng ◽  
Yan Wang ◽  
...  
Keyword(s):  
Risk Factors ◽  
Venous Thrombosis ◽  
Cancer Patients ◽  
Upper Extremity ◽  
Factors Associated

Combined effect of repetitive work and cold on muscle function and fatigue

2002 ◽  
Vol 92 (1) ◽  
pp. 354-361 ◽  
Author(s):  
Juha Oksa ◽  
Michel B. Ducharme ◽  
Hannu Rintamäki
Keyword(s):  
Muscle Function ◽  
Voluntary Contraction ◽  
Overuse Injuries ◽  
Emg Activity ◽  
Wrist Flexion ◽  
Fatigue Index ◽  
Local Cooling ◽  
Repetitive Work ◽  
Flexion Extension ◽  
Forearm Muscle

This study compared the effect of repetitive work in thermoneutral and cold conditions on forearm muscle electromyogram (EMG) and fatigue. We hypothesize that cold and repetitive work together cause higher EMG activity and fatigue than repetitive work only, thus creating a higher risk for overuse injuries. Eight men performed six 20-min work bouts at 25°C (W-25) and at 5°C while exposed to systemic (C-5) and local cooling (LC-5). The work was wrist flexion-extension exercise at 10% maximal voluntary contraction. The EMG activity of the forearm flexors and extensors was higher during C-5 (31 and 30%, respectively) and LC-5 (25 and 28%, respectively) than during W-25 ( P < 0.05). On the basis of fatigue index (calculated from changes in maximal flexor force and flexor EMG activity), the fatigue in the forearm flexors at the end of W-25 was 15%. The corresponding values at the end of C-5 and LC-5 were 37% ( P < 0.05 in relation to W-25) and 20%, respectively. Thus repetitive work in the cold causes higher EMG activity and fatigue than repetitive work in thermoneutral conditions.

Postmovement Changes in the Frequency and Amplitude of Physiological Tremor Despite Unchanged Neural Output

2010 ◽  
Vol 104 (4) ◽  
pp. 2020-2023 ◽  
Author(s):  
Raymond Reynolds ◽  
Martin Lakie
Keyword(s):  
Passive Movement ◽  
Muscle Stiffness ◽  
Emg Activity ◽  
Hand Position ◽  
Vertical Acceleration ◽  
Physiological Tremor ◽  
Joint Mechanics ◽  
Wrist Flexion ◽  
Temporary Reduction ◽  
Flexion Extension

Active or passive movement causes a temporary reduction in muscle stiffness that gradually returns to baseline levels when the muscle remains still. This effect, termed muscle thixotropy, alters the mechanical properties of the joint around which the muscle acts, reducing its resonant frequency. Because physiological tremor is affected by joint mechanics, this suggests that prior movement may alter tremor independently of neural output. To address this possibility, vertical acceleration of the outstretched prone hand was recorded in eight healthy subjects, along with EMG activity of the extensor digitorum communis muscle. A series of voluntary wrist flexion/extension movements was performed every 20 s, interspersed by periods during which hand position was maintained. Time-dependent changes in the amplitude and frequency of acceleration and EMG were analyzed using a continuous wavelet transform. Immediately following movement, acceleration displayed a significant increase in wavelet power accompanied by a reduction in peak frequency. During the postmovement period, power declined by 63%, and frequency increased from 7.2 to 8.0 Hz. These changes occurred with an exponential time constant of 2–4 s, consistent with a thixotropic mechanism. In contrast to acceleration, EMG activity showed no significant changes despite being strongly related to acceleration during the movement itself. These results show that prior movement transiently increases the amplitude and reduces the frequency of physiological tremor, despite unchanging neural output. This effect is best explained by a reduction in joint stiffness caused by muscle thixotropy, highlighting the importance of mechanical factors in the genesis of physiological tremor.

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.

Workplace Ergonomics: An Approach to Health, Safety, and Productivity

1994 ◽  
Author(s):  
Gary Kress
Keyword(s):  
Risk Factors ◽  
Back Stress ◽  
Cumulative Trauma Disorders ◽  
Cumulative Trauma ◽  
Paper Briefly ◽  
Job Requirements ◽  
Analysis And Design ◽  
Factors Associated ◽  
Related Risk ◽  
Trauma Disorders

Ergonomics is a discipline that considers the mental and physical capabilities and limitations of people in relation to the demands of their work. The goal of ergonomics is to minimize error and fatigue by matching job requirements with human abilities through a process of analysis and design in determining the dimensions and layout of the workspace, the design of tools and equipment, and the development of work procedures. When jobs fit people, the result is improved productivity, reduced accidents and injuries and greater job satisfaction. This paper briefly examines the ergonomic approach to identifying and reducing job related risk factors associated with cumulative trauma disorders and back stress. Examples of controls to eliminate risk factors are presented along with some workplace design principles and guidelines. Paper published with permission.

Pilot Study of Upper-Extremity Work and Power in Chronic Cumulative Trauma Disorders

1997 ◽  
Vol 17 (1) ◽  
pp. 3-24 ◽  
Author(s):  
T.L. Shackleton ◽  
K.L. Harburn ◽  
S. Noh
Keyword(s):  
Upper Extremity ◽  
Rating Scale ◽  
Numerical Rating Scale ◽  
Cumulative Trauma Disorders ◽  
Cumulative Trauma ◽  
Wrist Flexion ◽  
Retest Reliability ◽  
Work Related ◽  
Trauma Disorders ◽  
Test Retest Reliability

Research designed to increase our understanding of behavioral responses to chronic pain resulting from work-related cumulative trauma disorders (CTD) has been limited. This pilot study's main purpose was to examine the test-retest reliability of self-determined work and power during maximum and submaximum efforts in the performance of wrist flexion and extension movements of the CTD-affected extremity, using the LIDO WorkSET Simulator System. Data were collected from 22 subjects (11 men, 11 women) with chronic upper-extremity CTD, in two same-day sessions. Subjective reports of current pain in the CTD subjects were measured using a Visual Analogue Scale (VAS) and a Numerical Rating Scale (NRS). Upper-extremity work and power data were also collected on 12 healthy subjects as a control (6 men, 6 women). Pilot results included: acceptable test-retest reliability of the work and power measures in the CTD subjects; the CTD group demonstrated markedly lower (20% to 58%) maximum work, submaximum work, and maximum power values compared with the healthy group; gender variation was seen in the CTD and healthy groups with respect to work and power data, and women with CTD tended to report higher pain intensity than male cohorts. These results provide insight for future studies.

Risk factors associated with upper extremity palsy after expansive open-door laminoplasty for cervical myelopathy

2014 ◽  
Vol 14 (6) ◽  
pp. 909-915 ◽  
Author(s):  
Feng L. Wu ◽  
Yu Sun ◽  
Sheng F. Pan ◽  
Li Zhang ◽  
Zhong J. Liu
Keyword(s):  
Risk Factors ◽  
Upper Extremity ◽  
Cervical Myelopathy ◽  
Open Door ◽  
Factors Associated
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