The Influence of Hand Tool Design on Hand Grip Strength: A Review

Hand is made up of bones, tendons, ligaments, nerves and blood vessels that can be easily debilitated and injured if the hand tool is not design ergonomically. Recently researchers have examined the effects of individual, environmental and occupational factors on hand grip strength. However, information on the influence of hand tool design on hand grip strength is still lacking. The aim of this paper is to provide a comprehensive review of factors influencing hand grip strength focusing more towards hand tool design factors. The authors searched the journal articles, book and guidelines from the online databases of Google Scholar, ScienceDirect and Pubmed. Fourteen factors of hand tools design were found to have significant effect on the hand grip strength.  The handle size shows the most significant factor for hand grip strength

Effect of overhead drilling support on muscular activity of shoulder

This study examines the effect of an overhead drilling support and position of the arm on muscular activity of the shoulder. Five male participants simulated an overhead drilling task by using a drill in near, middle and far reach positions. Electromyographic measurements were taken from the dominant side anterior deltoid, bicep and trapezius muscles. Root mean square amplitude (RMS) of the EMG activity from these muscles was used to determine the load on the muscular system. The participants used a subjective rating scale to evaluate the overhead support stand and holding position. The results demonstrate that the overhead support stand was effective in reducing the muscular load. The mean RMS value reduction with overhead support stand, when compared to the without support in bicep muscles during near, middle and far reach positions were 18%, 24 % and 47%, respectively. For anterior deltoid muscles the percentage decrease in mean RMS values for near, middle and far reach positions were 24%, 33% and 49%, respectively; and for trapezius muscles the percentage decrease in mean RMS values during near, middle and far reach positions were 32%, 33% and 42%, respectively. The middle reach position, in contrast to near and far reach positions resulted in the lowest RMS values. The mean RMS values without support stand for biceps muscles was the lowest in middle position (0.139mv). Similarly the mean RMS values of anterior deltoid (0.231mv) and trapezius (0.066mv) muscles without overhead support stand were least for the middle position. The mean RMS values for the bicep (0.105 mv), anterior deltoid (0.155mv) and trapezius (0.041mv) muscles with overhead support stand were the lowest during the middle position. The subjective rating results also supported the above conclusions. These findings indicate that workers performing overhead drilling tasks in coronal plane should work in middle position in order to reduce the muscular load

Ergonomiska principer avseende arbete med rak handled och handgrepp - En litteraturstudie

Bakgrund: Idag drabbas många äldre personer samt personer i arbetsför ålder av olika handåkommor. Arbetsrelaterade belastningsskador orsakas bland annat av repetitiva arbetsuppgifter, ogynnsam handledsposition samt dåligt utformade verktyg. Många studier har visat att karpaltunnelsyndrom kan förebyggas om arbete utförs med handleden i en neutral position och om ergonomiskt utformade verktyg används. Forskning har också visat att användande av ergonomiskt anpassade verktyg samt tillämpning av ergonomiska råd, kan ge personer med handåkommor ett bättre handgrepp och en ökad handstyrka. Syfte: Syftet med studien var att undersöka kunskapsläget för ergonomiska principer avseende arbete med rak handled och handgrepp som rekommenderas inom arbetsterapi. Metod: En scopingmetod har använts för att undersöka kunskapsläget i tio vetenskapliga artiklar med olika forskningsmetoder. De valda studierna undersökte ergonomiskt utformade tangentbord, handtag på tänger och olika handtag och dess inverkan på hälsa, aktivitetsutförande samt produktivitet. Deltagarna var mellan 18-96 år. Resultat: Fem av de tio studierna visade att ulnar-radial deviation samt flexion-extension i handleden kan undvikas genom användning av de ovan nämnda verktygen. En av dessa fem studier visade att det inte fanns något bevis som styrkte att ett ergonomiskt anpassat tangentbord kunde ha någon effekt för personer med karpaltunnelsyndrom. De fem återstående studierna visade att en högre greppstyrka och ett bättre grepp bland annat kan bero på yttexturen på föremålets yta, samt verktygets storlek och diameter. Bland de angivna förslagen ansågs 33 mm vara den optimala diametern för både män och kvinnor. Handtag som är avsedda för att användas för aktiviteter som kräver en hög precision, visade att ett mått som hade 12 mm och 20 mm var det optimala. Konklusion: Studiens resultat pekar på att ergonomi avseende personer med nedsatt funktion i hand och arm, lägger mycket fokus på både förebyggande och rehabiliteringsåtgärder

Madala maksumusega elektromüograafide rakendatavus ergonoomikalises hindamises

A thesis for applying for the degree of Doctor of Philosophy in Engineering Sciences.Every year a considerable amount of gross domestic product in several countries is lost due to work-related musculoskeletal disorders (WMSDs). Thus, one of the goals of ergonomics is to prevent WMSDs. A body of knowledge required to prevent WMSDs has existed for decades; however, the exploitation of this knowledge is hindered by the shortcomings in the risk assessment methods. As a rule, objective methods should be preferred to subjective methods, though often access to objective methods is restricted by the cost of the apparatus. The potential to make one of such devices more accessible by reducing the costs was investigated in the thesis. The thesis focused on the electromyograph – a device to study and monitor the electrical activity produced by skeletal muscles. Nowadays one can assemble an electromyograph from low-cost semi-universal components; however, the functionality and usability of such a device is unknown. At first the technical characteristics of components that can be used to assemble an electromyograph were evaluated. Then the electromyographs were assembled and tested in the laboratory and in the field. The results showed that the low-cost electromyographs may be partially utilised in ergonomic risk assessment; however, the use of such equipment in comparison to commercial high-cost apparatus increases the demands on user knowledge, skills and time expenditure. On the other hand, the functionality of the do-it-yourself electromyograph may exceed the commercial device.Tööga seotud luu- ja lihaskonna ülekoormushaiguste tõttu kaotavad riigid igal aastal märkimisväärse osa sisemajanduse kogutoodangust. Seetõttu on üheks ergonoomika eesmärgiks luu- ja lihaskonna ülekoormushaiguste ennetamine. Teadmised töötaja ülekoormuse ennetamiseks on olemas juba aastakümneid. Paraku takistavad teadmiste tõhusat rakendamist puudused riskihindamise meetodites. Riskide hindamisel tuleb subjektiivsetele meetoditele eelistada objektiivseid meetodeid, kuid sageli piirab objektiivsete meetodite kasutamist mõõteseadmete maksumus. Doktoritöös uuriti ühe sellist liiki mõõteseadme, lihaste elektrilise aktiivsuse uurimiseks mõeldud seireseadme ehk elektrimüograafi kättesaadavuse ja rakendamise suurendamise võimalust seadme maksumuse vähendamisega. Nüüdisajal on võimalus elektromüograafe kokku panna madala maksumusega ja pool-universaalsetest komponentidest. Samas pole selge, milline on sellisel viisil valmistatud elektromüograafi funktsionaalsus ja kasutatavus. Doktoritöös hinnati esmalt elektromüograafi madala maksumusega komponentide tehnilisi omadusi ning seejärel katsetati koostatud elektromüograafe laboris ja töökeskkonnas. Doktoritöö andis kinnitust, et madala maksumusega elektromüograafe on võimalik riskihindamisel osaliselt rakendada, kuid selliste seadmete kasutamine eeldab riskihindajalt põhjalikumaid teadmisi ja oskusi ning suuremat ajakulu kui kallite kommertsseadmete kasutamine. Samas võib spetsialisti kokkupandud elektromüograafi funktsionaalsus kommertsseadmeid ületada.Publication of this thesis is supported by the Estonian University of Life Sciences. This research was supported by European Regional Development Fund’s Doctoral Studies and Internationalisation Programme DoR

Cumulative trauma disorders in the workplace: bibliography

"This publication provided a compilation of materials describing research conducted by NIOSH on cumulative trauma disorders in the workplace. Selected references, both NIOSH and nonNIOSH, were provided, concentrating on NIOSH activities in preventing work related musculoskeletal disorders, prevention and intervention research at NIOSH for work related musculoskeletal disorders, comments to the Department of Labor on the OSHA proposed rule on ergonomic safety and health management, a manual for musculoskeletal diseases of the upper limbs, a review of physical exercises recommended for video display tube operators, management of upper extremity cumulative trauma disorders, ergonomics and prevention of musculoskeletal injuries, and carpal tunnel syndrome. A bibliography of NIOSH publications on cumulative trauma disorders in the workplace was provided, including numbered publications, testimony, journal articles, grant reports, contract reports, and health hazard evaluations. NonNiosh references were also listed." - NIOSHTIC-2Part I. Selected NIOSH and non-NIOSH References -- A. NIOSH Activities in Preventing Work-Related Musculoskeletal Disorders -- B. Work-Related Musculoskeletal Disorders: Prevention and Intervention Research at NIOSH -- C. Comments to DOL on the Occupational Safety and Health Administration Proposed Role on Ergonomic Safety and Health Management - Part 1 -- C. Comments to DOL on the Occupational Safety and Health Administration Proposed Role on Ergonomic Safety and Health Management - Part 2 -- D. Cumulative Trauma Disorders: A Manual for Musculoskeletal Diseases of the Upper Limbs -- E. A Review of Physical Exercises Recommended for VDT Operators ) -- F. Management of Upper Extremity Cumulative Trauma Disorders -- G. Preventing Illness and Injury in the Workplace: Ergonomics and Prevention of Musculoskeletal Injuries -- H. Carpal Tunnel Syndrome -- -- Part II. Cumulative Trauma Disorders in the Workplace - Bibliography -- A. NIOSH Publications Reports -- 1. Numbered Publications -- 2. Testimony -- 3. Journal Articles -- 4. Grant Reports -- 5. Contract Reports -- 6. Health Hazard Evaluations -- -- B. Selected non-NIOSH ReferencesAlso available via the World Wide Web

An analysis of the prevalence of musculoskeletal disorders in heavy, civil construction operations and the impact of job, age, and experience

Includes bibliographical references

Work-related upper limb disorder:- An investigative study

The primary aim of occupational health staff within a manufacturing company is to ensure the health and well being of the employees are safeguarded. The aim may be difficult to achieve as it goes directly against the ethos of business, i.e. making money. It is the researcher's experience that company owners, especially Far Eastern owners, are disinclined to introduce health and safety measures that cost money. The study is conducted in an electronic company (Company X) in the northeast of England, owned by foreign nationals. Retrospective examination of accident, sickness and absenteeism records reveal that work-related upper limb disorder (WRULD) is apparent and upper limb discomfort is a significant problem in Соmpany X. Research shows that the principle of job rotation tends to reduce fatigue and the incidence of WRULD, consequently sickness and absenteeism and labour turnover will also be reduced. In Company X physiological stress to the limb is highly relevant to the production line workers, based on case studies of employees with work-related upper limb disorder. This led to conducting a study of two sites building different electrical equipment. 80 employees participated in the study which involved monitoring the employees on six paced production lines in the Personal Computer Monitor factory PCM which included seven teams and employees in five teams on four production lines in the Microwave Oven Factory. A semi paced line, the Bent Tool Machine BTM in MWO were also involved in the job rotation experiment. Discomfort scale measurements were administered to all that took part and an extra objective measurement of grip strength was provided by the employees in the BTM to provide information on fatigue. A comparison between grip strength and discomfort was analysed for any con-elation. The main data collection took place between September and December 2000.There is some evidence that the differences in discomfort is caused by job rotation as where job rotation was taking place the employees in the study had lower levels of discomfort than those on non- rotational duties. In the CDT prep job PCM where job rotation was taking place a comparison between job rotation and the non-rotation group with regard to discomfort in body parts differed (Fisher's exact test, p=0.05).The job action analysis that was designed specifically for the production line environment allowed comparisons of upper limb score for different jobs. It would appear that regular job analysis should be introduced as a matter of practice in Company X in the future. The study demonstrated the importance of prevention and innovation ergonomics and there was evidence to suggest that the occupational health department should adopt an active role in the future for the benefit of the employees and the financial survival of the Company

Some NASA contributions to human factors engineering: A survey

This survey presents the NASA contributions to the state of the art of human factors engineering, and indicates that these contributions have a variety of applications to nonaerospace activities. Emphasis is placed on contributions relative to man's sensory, motor, decisionmaking, and cognitive behavior and on applications that advance human factors technology

An exploratory study of ergonomic work practices in selected small manufacturing engineers.

Thesis (MBA)-University of KwaZulu-Natal, Durban, 2004.Many organizations are using ergonomic principles and its applications to improve and optimize the current levels of productivity, safety and health. This can be achieved by carefully examining the current management and work practices with the view of finding alternative ways to perform these tasks. In view of the above this research examines the current management and work practices of three small manufacturing engineers, with the purpose of providing inputs, to improve their current status through the application of ergonomic principles. The study is divided into three parts. The first part focuses on the review of current literature on ergonomics and specifically discusses issues such as anthropometry, cumulative trauma disorders, manual material handling, and ergonomic based management systems. The second part focuses on an assessment and identification of existing problems and areas of weaknesses in the workplace. This was accomplished through in depth interviews, observation and questionnaires. The final part presents the research findings followed by the discussion and proposed recommendations. The study has revealed that there is a fundamental lack of knowledge of ergonomics and its relationship to productivity, safety and health. Currently most work practices are guided by what has been learnt and internalized over the years. The researcher proposes that in order to successfully implement an ergonomics programme, ergonomic awareness, training and education, self help training, management commitment and work force participation are essential