Slide 1Slide 27 Other MTM-2 Elements - 1Other 7 Elemental Motions - 2Other 7 Elemental Motions - 3MTM-2 ApplicationSummary of MTM-2 DataInsertion vs. Alignment PUTContinuous vs. Intermittent CrankSlide 10Other Special CasesSlide 12Sources of ErrorSlide 14Job Analysis - Surveys #1 Body discomfort maps (Corlett,1976) Category ratio (CR-10) scale (Borg, 1982)Job Analysis - Surveys #2 Nordic Questionnaire (Kuorinka, 1987)Job Analysis - Surveys #2 Nordic Questionnaire con’tGross Posture Categorization #3OWAS Code = 2151 2 = bent back 1 = both arms below shoulders 5 = kneeling 1 = <10 kg loadOWAS – Acceptable LimitsSlide 21Comments on SurveysIE 5531IE 553 Engineering of Human WorkDr. Andris FreivaldsClass #17IE 5532IE 553 Engineering of Human WorkDr. Andris FreivaldsClass #17IE 55337 Other MTM-2 Elements - 13) Apply Pressure (A) = 14 TMU•Exert muscular force on object •Without moving it (otherwise G or P)•Ex: push button4) Regrasp (R) = 6 TMU•Change position of object•Without relinquishing control (otherwise G)•Ex: reorient toolIE 5534Other 7 Elemental Motions - 25) Eye Action (E) = 7 TMU•Recognize an object or•Shift line of sight out of normal area of vision•Don’t overdue, G and P have already6) Crank (C) = 15 TMU/rev•Hand/fingers move in circular path > ½ rev•If < ½ rev, use G and/or P•May need GW to overcome stiction•May need PW for sticky crankIE 5535Other 7 Elemental Motions - 37) Steps (S) = 18 TMU/step•Leg motion to move body, •Distance > 12”8) Foot Motion (F) = 9 TMU•Short foot motion, to press pedal•Distance < 12”9) Bend & Arise (B) = 61 TMU•Vertical displacement of body•Bend, stoop, kneel on one knee•Kneel on both knees = 2BIE 5536MTM-2 Application1) Use MTM Methods Analysis Chart2) Summarize motions by hand (L & R)3) Add TMUs (no ratings needed)4) Add allowances5) Consider special casesIE 5537Summary of MTM-2 DataIE 5538Insertion vs. Alignment PUTRH TMUPPIE 5539Continuous vs. Intermittent CrankContinuous C Intermittent CGB 18 18GW 10 53C 453PW 10 3Total 71IE 553101) Simultaneous Motion• Simo difficult motions require more time• Add a penaltyIE 55311Other Special Cases2) Principle of limiting motion –For two different motions for each hand–Use the longer time3) Principle of combined motion–For two combined motion in one hand–Use longer time4) R is included in C-type motionsIE 55312ExamplesIE 55313Sources of Error•Discreteness – tabular data–No interpolation–Hopefully, this averages out•Synthesis assumes correct process•Need correct application - practiceIE 55314Ex: U-bolt assemblyIE 55315Job Analysis - Surveys #1 Body discomfort maps (Corlett,1976) Category ratio (CR-10) scale (Borg, 1982)IE 55316Job Analysis - Surveys #2Nordic Questionnaire (Kuorinka, 1987)IE 55317Job Analysis - Surveys #2Nordic Questionnaire con’tIE 55318Gross Posture Categorization #3•Owaco Working Posture Analysis System (OWAS, Karhu, 1977)•Developed at the Finnish Institute of Occupational Health in 1970s•For use in steel industry•Evaluation of posture at regular intervals•Four categories: back, upper limbs, lower limbs, force (<10, <20, >20 kg)IE 55319OWASCode = 2151 2 = bent back1 = both arms below shoulders5 = kneeling 1 = <10 kg loadIE 55320OWAS – Acceptable LimitsMeasure %time in each postureIE 55321Gross Posture Categorization #4(Keyserling, 1986)IE 55322Comments on Surveys•Should interpret with caution•Workers hesitant to be truthful•Anonymity may be critical•Pain tolerances vary•Proper design, validation critical•Fairly subjective (objective!)•Relatively non-quantitative•More covered in IE 552 (upper
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