Effect of aviation snip design and task height on upper extremity muscular activity and wrist posture

A science mapping-based review of work-related musculoskeletal disorders among construction workers

INTRODUCTION

Work-related musculoskeletal disorders (WMSDs) are recognized as a leading cause of nonfatal injuries in construction, but no review of existing studies has systematically analyzed and visualized the trends of WMSDs among construction workers. The current science mapping-based review summarized research published between 2000 and 2021 related to WMSDs among construction workers through co-word, co-author, and citation analysis.

METHOD

A total of 63 bibliographic records retrieved from the Scopus database were analyzed.

RESULTS

The results identified influential authors with high impacts in this research domain. Moreover, the results indicated that MSDs, ergonomics, and construction not only had the highest occurrence of been studied, but also the highest impact in terms of total link strength. In addition, the most significant contributions to research relating to WMSDs among construction workers have originated primarily from the United States, Hong Kong, and Canada. Furthermore, a follow-up in-depth qualitative discussion was conducted to focus on summarizing mainstream research topics, identifying existing research gaps, and proposing directions for future studies.

CONCLUSIONS

This review provides an in-depth understanding of related research on WMSDs among construction workers and proposes the emerging trends in this research field.

Biomechanical factors during common agricultural activities: Results of on-farm exposure assessments using direct measurement methods

Agricultural work is associated with increased risk of adverse musculoskeletal health outcomes. The purpose of this study was to quantify exposure to biomechanical factors among a sample (n = 55) of farmers in the Midwest region of the U.S. while they performed a variety of routine agricultural activities, and to compare exposure levels between these activities. Surface electromyography was used to estimate activity levels of the erector spinae, upper trapezius, forearm flexor, and forearm extensor muscle groups. Simultaneously, inertial sensors were used to measure kinematics of the trunk, upper arm, and wrist. In general, lower muscle activity levels, less extreme postures, and slower movement speeds were observed during activities that involved primarily the use of agricultural machinery in comparison to manual activities, suggesting a potential advantage of mechanization relative to musculoskeletal health. Median wrist movement speeds exceeding recently proposed exposure thresholds were also observed during many manual activities, such as milking animals and repairing equipment. Upper arm postures and movement speeds did not appear to confer excessive risk for shoulder-related outcomes (on the whole), but interpretation of the results is limited by a sampling approach that may not have captured the full extent of exposure variation. Not surprisingly, substantial variation in exposure levels were observed within each agricultural activity, which is related to substantial variation in the equipment, tools, and work practices used by participants. Ultimately, the results of this study contribute to an emerging literature in which the physical demands of routine agricultural work have been described on the basis of sensor-based measurements rather than more common self-report or observation-based approaches.

Non-powered hand tool improvement research for prevention of work-related problems: a review

PURPOSE

In lower-middle-income countries, most of the work is performed manually using non-ergonomic hand tools which results in work-related health problems. Using hand tools designed in line with ergonomic principles may play an important role in reducing work-related health concerns significantly.

METHODS

Scientific databases (PubMed, EBSCOhost) and e-publishers were searched for articles from 1985 to 2015 using the following keywords: 'hand tool', 'ergonomics', 'usability' and 'design'. After applying selection criteria to 614 articles, 58 articles related to the physical design of hand tools were selected.

RESULTS

Seventeen articles were related to hand tool improvement in the manufacturing sector. Musculoskeletal disorders were found to be the most frequently occurring work-related health problems. Most of the articles focused on product and qualitative variables for improvement in hand tools, while few articles considered human and task variables.

CONCLUSIONS

Literature shows that hand tool improvement studies have been given less importance in low-income and lower-middle-income countries. However, some work of significance is reported in the agriculture sectors of these countries. Hence, it is concluded that ergonomic intervention in hand tools is much needed for those industries which employ traditional methods of working.

Ergonomic analysis of robot-assisted and traditional laparoscopic procedures

INTRODUCTION

Many laparoscopic surgeons report musculoskeletal symptoms that are thought to be related to the ergonomic stress of performing laparoscopy. Robotic surgical systems may address many of these limitations. To date, however, there have been no studies exploring the quantitative ergonomics of robotic surgery. In this study, we sought to compare the activation of bilateral biceps, triceps, deltoid, and trapezius muscle groups during traditional laparoscopic surgery (TLS) and robot-assisted laparoscopic surgery (RALS) procedures, as quantified by surface electromyography (sEMG).

METHODS

One surgeon with expertise in TLS and RALS performed 18 operative procedures (13 TLS, 5 RALS) while sEMG measurements were obtained from bilateral biceps, triceps, deltoid, and trapezius muscles. sEMG measurements were normalized to the maximum voluntary contraction of each muscle (%MVC). We compared mean %MVC values for each muscle group during TLS and RALS with unpaired t-tests and considered differences with a p value <0.05 to be statistically significant.

RESULTS

Muscle activation was higher during TLS compared to RALS in bilateral biceps (L Biceps RALS:1.01%MVC, L Biceps TLS:3.14, p = 0.01; R Biceps RALS:1.81%MVC, R Biceps TLS:4.53, p = 0.0002). Muscle activation was higher during TLS compared to RALS in bilateral triceps (L Triceps RALS:1.73%MVC, L Triceps TLS:3.58, p = 0.04; R Triceps RALS:1.59%MVC, R Triceps TLS:5.11, p = 0.02). Muscle activation was higher during TLS compared to RALS in bilateral deltoids (L Deltoid RALS:1.50%MVC, L Deltoid TLS:3.68, p = 0.03; R Deltoid RALS:1.19%MVC, R Deltoid TLS:2.57, p = 0.01). Significant differences were not detected in the bilateral trapezius muscles (L Trapezius RALS:1.50 %MVC, L Trapezius TLS:3.68, p = 0.03; R Trapezius RALS:1.19%MVC, R Trapezius TLS:2.57, p = 0.01).

DISCUSSION

We have quantitatively examined the ergonomics of TLS and RALS and shown that in a single surgeon, TLS procedures are associated with significantly elevated biceps, triceps, and deltoid activation bilaterally when compared to RALS procedures.

FLS tasks can be used as an ergonomic discriminator between laparoscopic and robotic surgery

INTRODUCTION

Robotic surgery may result in ergonomic benefits to surgeons. In this pilot study, we utilize surface electromyography (sEMG) to describe a method for identifying ergonomic differences between laparoscopic and robotic platforms using validated Fundamentals of Laparoscopic Surgery (FLS) tasks. We hypothesize that FLS task performance on laparoscopic and robotic surgical platforms will produce significant differences in mean muscle activation, as quantified by sEMG.

METHODS

Six right-hand-dominant subjects with varying experience performed FLS peg transfer (PT), pattern cutting (PC), and intracorporeal suturing (IS) tasks on laparoscopic and robotic platforms. sEMG measurements were obtained from each subject's bilateral bicep, tricep, deltoid, and trapezius muscles. EMG measurements were normalized to the maximum voluntary contraction (MVC) of each muscle of each subject. Subjects repeated each task three times per platform, and mean values used for pooled analysis. Average normalized muscle activation (%MVC) was calculated for each muscle group in all subjects for each FLS task. We compared mean %MVC values with paired t tests and considered differences with a p value less than 0.05 to be statistically significant.

RESULTS

Mean activation of right bicep (2.7 %MVC lap, 1.3 %MVC robotic, p = 0.019) and right deltoid muscles (2.4 %MVC lap, 1.0 %MVC robotic, p = 0.019) were significantly elevated during the laparoscopic compared to the robotic IS task. The mean activation of the right trapezius muscle was significantly elevated during robotic compared to the laparoscopic PT (1.6 %MVC lap, 3.5 %MVC robotic, p = 0.040) and PC (1.3 %MVC lap, 3.6 %MVC robotic, p = 0.0018) tasks.

CONCLUSIONS

FLS tasks are validated, readily available instruments that are feasible for use in demonstrating ergonomic differences between surgical platforms. In this study, we used FLS tasks to compare mean muscle activation of four muscle groups during laparoscopic and robotic task performance. FLS tasks can serve as the basis for larger studies to further describe ergonomic differences between laparoscopic and robotic surgery.

Estudo comparativo da força muscular da mão entre cadetes homens e mulheres da Força Aérea Brasileira

O objetivo do estudo foi quantificar a força muscular da mão, nos movimentos de preensão palmar e três tipos de pinça, comparando os cadetes homens e mulheres. Foram avaliados 31 cadetes da Academia da Força Aérea Basileira, sendo 17 homens e 14 mulheres, com os dinamômetros Jamar e Preston Pinch Gauge. A média de preensão das mulheres foi de 31,4 kgf no lado dominante e 29,3 kgf no lado não-dominante; nos homens, foi 43,6 e 41,2 kgf, respectivamente (p<0,01). Na pinça lateral, a média feminina foi de 7,4 kgf e masculina, 10,2 kgf, no lado dominante (p<0,01); na pinça trípode, a média das mulheres foi de 7,2 kgf no lado dominante e 7,1 kgf do lado não-dominante; nos homens, foi respectivamente de 9,8 kgf e 9,5 kgf (p<0,01); na pinça polpa-a-polpa, as médias femininas foram de 4,9 e 4,6 kgf nos lados dominante e não-dominante; dos homens, foram de 6,5 e 5,7 kgf nos lados dominante e não-dominante, respectivamente (p<0,01). A força de preensão palmar, pinça lateral, pinça trípode e pinça polpa-a-polpa foi significantemente maior nos cadetes masculinos do que nas mulheres. Ambos os sexos mostraram mais força do lado dominante do que no não-dominante, exceto na pinça trípode. Quando comparados à população em geral, há pouca diferença dos valores obtidos nos cadetes, tanto em relação ao sexo quanto à dominância. Esses achados podem ser relevantes na avaliação fisioterapêutica e para o desempenho desses pilotos.