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This topic contains 11 replies, has 8 voices, and was last updated by  yaniel 10 years, 5 months ago.

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  • #36588

    yaniel
    Participant

     Hi

    I would like to know when consider a work as repetitif. There is some concenus around this subject? Please could you refer me some bibliography references to get  in deep I supouse that the repetitiveness has not the same effect in each part of the body. I am really interested to know limits values  for repetitif work. 

    #39759

    [email protected]
    Participant

    Yaniel,

    MSD risk is a function of multiple risk factors, such as force, posture, repetition, duration. These factors interact to determine risk.

    For example, lifting a 150 lb. box 1 time could be considered a high risk. So, even though it is low repetition, the high force requirement pushes the risk high. Ergonomists use analytical methods like the NIOSH Lifting Equation to analyze the lifting risk by taking into acount many risk factors.

    Likewise, we use a variety of other analytical tools (e.g, Strain Index, Biomechanical models, Physiological/Metabolic models, Rodgers/Kodak Muscle Fatigue Analysis, RULA, etc.) to analyze risk for different types of tasks and body regions.

    So, there is no simple definition of what is considered "repetitive." It depends entirely on the levels of the other risk factors, and the body region of concern.

    Peter Budnick, PhD, CPE
    Ergoweb Inc.

    #40723

    [private user]
    Participant

    Yaniel

    The Health and Safety Executive in the UK suggests that lifting / lowering is relatively infrequent at rates upt to about 30 operations per hour, or one lift every two minutes or less (L23, p56, free PDF available via http://books.hse.gov.uk/hse/public/saleproduct.jsf?catalogueCode=9780717628230).

    For upper limb tasks the guidance (HSG60rev, p67, free PDF available via http://books.hse.gov.uk/hse/public/saleproduct.jsf?catalogueCode=9780717619788) highlights three indicators: 

    1) Repeating the same motions every few seconds; 2) A sequence of movements repeated more than twice per minute; 3) More than 50% of the cycle time involved in performing the same sequence of motions.  These are qualified by the need for the activity to last for more than two hours total per shift.

    Regards

    Andrew

     

     

    Dr Andrew Pinder, PhD, MSc, MErgS
    Ergonomics Section
    Health and Safety Laboratory, Harpur Hill, Buxton, SK17 9JN, UK
    HSL home page: http://www.hsl.gov.uk/
    HSE home page: http://www.hse.gov.uk/

    #40748

    [private user]
    Participant

     

    Yaniel –

     

    Hope this table helps.

     

    Categories of Repetitiveness for Hand-Intensive Tasks (from You and Kwon, 2005)

    Measure

     

    Repetitiveness Classification

    Criterion

    Source

    Cycle Time (CT)

    Overall Work CT (OCT)

    High

    OCT<30 seconds or same types of fundamental cycles >50% of the OCT

    Silverstein, et al. (1986)

    Low

    OCT>30 seconds and same types of fundamental cycles <50% of the OCT

    Fundamental Work Cycle (FCT)

    High

    FCT<2 seconds

    Hansson, et al. (1996)

    Moderately High

    2<FCT<5 seconds

    Moderately Low

    5<FCT<10 seconds

    Low

    10 seconds < FCT

    Movement Frequency (MF)

    Finger MF

    High

    MF>200 motions per minute

    Kilbom (1994)

    Low

    MF<200 motions per minute

    Hand/Wrist MF

    High

    MF>20 motions per minute

    Li and Buckle (1998)

    Moderate

    10<MF< 20 motions per minute

    Low

    MF < 10 motions per minute

    Forearm / Elbow MF

    High

    MF > 4 motions per minute

    McAtamney and Corlett (1993)

    Low

    MF < 4 motions per minute

    Arm / Shoulder MF

    High

    MF > 4 motions per minute

    Low

    MF < 4 motions per minute

     

     

     

     

    #40812

    aprw287
    Participant

    Good morning Yaniel – your questions have been well answered by some good experts – I am writing simply to comment that we finally had some of the science and use of guidelines brought to this question which is great to see.

    We regularly purchase Dr Selan’s Guidelines books and refer to this web page as they are both excellent evidence based resources for our own practice in Canada.

    You are in good hands with this one.  Let us know how your analysis turns out!

    JE Sleeth Sr Consultant OPC Inc

    [email protected]

    #40816

    yaniel
    Participant

      Dear professor Selan

     I am really satisfied with your response but the articles from which you have taken the table do not have into consideration the limit of repetitivness given by ISO 11228-3 2007 that should be because their article  is from 2005 and the standard was published 2 years after. This standard is completely based in OCRA method developed by professor Daniela Colombini  Enrico Occhipinti from Clinica del Laboro Milano, the last one is also the chair of MSD technical Committee of the IEA.The OCRA stablish a limit of 30 technical action per minutes being really important to understand the concept of technical action which is more complex than a simple movement of a joint and similar to basic element in MTM UAS sytem but not exactly.

    In my case I have had the honor to share with Enrico and Daniela during a visit to Cuba last February, they gave a course in OCRA check list.

    Now since 3 month ago I am in Canada in Montreal at UQAM University for scientific interchange in order to support my PhD project. I am working with the Direction of Public Health of Montreal with ergonomist of this institution. A major concern regarding the MSD risk factor is the development of tool for a quick screening of work situation, this screening should be carried out by teams of practitioners in work Health of the Public health network. Usually with time constrain and not properly supported by the companies, often the detection of MSD risk should lead to the inclusion of this subject in a Program of Health Specific to the Company (PSSE in french)and if we consider that there is almost no situation in which MSD risk factor are not present so the problem is to determine when a significant ¨amount of Risk¨ is present to justified his inclusion in a PSSE. So tools like OCRA, Strain Index or even check list would not be suitable at this stage (the inclusion of MSD subject in a PSSE lead to a more detailed analyze of situation with this kind of tools).

    If two o three ergonomist like you carry a visit to an enterprise such as the one that practitioner have to conduct I am pretty sure that at the end of the visit you will be able to identify the situation with the amount of risk justifying his inclusion in a PSSE, but what were de determinant of the work task that conduct you to say: this situation yes, this one not enough? Moreover without using any Video, Method of analyze or any other tool. I am trying to find this determinant; of course the experience and the level of knowledge in the subject are very influents aspects in the decision process.

     In this moment I I am looking for TLVs that could help in some way to a rapid identification of a risk but TLV based in a scientific consensus like the limits proposed by ISO 11228 which at certain stage have been analyze by experts.

    Finally another concern is the inter observer reliability in this quick decision process.

    Best Regards

    Yaniel

    #40817

    yaniel
    Participant

     Thanks Jane,

    #39769

    danieljones2006
    Participant

    my warning to you today is to be careful of repetitive work. You may think it leaves you time to ponder and philosophise… but it may just be deadening you to more energetic thinking.

    #39770

    martcorb
    Participant

     Hi Yaniel,

    I work as an ergonomic consultant in Québec and I am often involved in Court to present ergonomic assessment regarding MSD.

    You might consider reading these:

    Bernard, B.P. 1997. Musculoskeletal disorders and w. Cincinnati, OH: National Institute of Occupational Safety and Health.

    . 2001. Criteria document for evaluating the work-relatedness of upper-extremity musculoskeletal disorders. Scandinavian Journal of Work, Environment and Health. 27 suppl 1:1-102.


    normal”>. Work related neck–shoulder pain: a review on magnitude, risk factors, biochemical characteristics, clinical picture and preventive interventions.. Best Practice & Research Clinical Rheumatology.. 2005. Musculoskeletal disorders of the upper extremity associated with computer work: A systematic review. Occupational Ergonomics 5: 205-218.

    van Rijn R.M, Huisstede B.MA, Koes B.W., Burdof A. 2009. Associaiton between work-related factors and the carpal tunnel syndrome- a systematic review. Scandinavian Journal of Work, Environment and Health. 35 (1): 19-36.

      

    As you are working on something similar, you should take a look at the QEC from the CSST (http://www.csst.qc.ca/publications/200/dc_200_698.htm)

     

    Have a good reading!

     

    Martin Corbeil M.Sc. Ergonome, CGL Ergonomie inc


    #39832

    RobRuss
    Participant

    You may also want to consult the following website:  http://www.acc.co.nz/PRD_EXT_CSMP/groups/external_providers/documents/guide/wcmz002335.pdf

    for an excerpt from Matheson LN.  Chapter 18:  Functional Capacity Evaluation. pp168-188.  IN:Demeter SL Anderson GBJ Smith GM. Disability Evaulation.  Mosby.  American Medical Association. 1996

    #39914

    aprw287
    Participant

    Hi Yaniel – you are studying at my old stomping grounds as I grew up in Montreal – enjoy the city!

    I see you have had some of the top experts help you out with your question – and we often refer to Dr Budnick and Dr Selan’s work in our own ergonomic analysis.  B Silversteins concept of the combination of hazards which creates potential ergonomic risk on an exponential level is also helpful.

    We hired a Masters levels student from the U of Windsor in Ontario to take all of the Ministry of Labour for Ontario’s ergonomic standards (if you call them they will deny they use standards however this is misinformation on their part!) and we validated each one in the literature and then used them in reliability studies at Chrysler in Brampton ON, the TTC in Toronto, the Coast Mountain Bus Co in Vancouver BC (Joint project with Worksafe and Coast Mountain) and then with the WHSCC in NFLD/Labrador.

    This is published in Lori Ross’s Masters Thesis with the U of Waterloo – each of our consultants across Canada is only allowed to use these standards when analyzing job demands for our clients. Depending on the nature of the work and the job demands we will often use a few standards to ensure the data is more reliable – Z-365, Dr Selan’s approach, and Kilbom, A are most commonly used by our team.

    Thank you for your feedback about our firm and website – we work hard to bring good science to ergonomics to the benefit of our clients

    Let me know if this is helpful to you and best of luck with your continued studies!

    JE Sleeth OPC Inc

    #39918

    [private user]
    Participant

    Hi Jane

     

    Your reference to the work by Lori Ros’s ergonomics standards interests me.  Is her thesis available anywhere on line?

    Regards

    Andrew

    Dr Andrew Pinder, PhD, MSc, MErgS
    Ergonomics Section
    Health and Safety Laboratory, Harpur Hill, Buxton, SK17 9JN, UK
    HSL home page: http://www.hsl.gov.uk/
    HSE home page: http://www.hse.gov.uk/

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