{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/34277"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/34277","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Effects of Work Exposure on Maximum Acceptable Repetition Rates in a Manual Torquing Task","abstract":"Repetitive and forceful exertions have been dentified as an important risk factor for occupational injuries. One method used to determine appropriate exposures to these and other risk factors is psychophysics, which is based on individual perceptions of task demands and/or risk. Effects of work exposure have been indicated as of potential importance, but have not been well studied. Indications from an earlier study related to psychophysical limits for a repetitive manual torquing task were that five days of work conditioning had minimal effects on resulting Maximum Acceptable Repetition Rates (MARR). However, it is unknown whether and how longer work exposure durations might influence MARRs. The current study investigated the effects of work exposure on MARR and adjustment time over 10 working days (two weeks) with two days of rest after five days. Ten participants (five males and five females) performed a manual torquing (45 Nm load) task at mid-chest level in the coronal plane for a one hour test session. Starting repetition rate for each participant was set at single high and low rate on alternate days. Temporal (exposure) effects were determined, where day of exposure was the independent variable, and MARR and adjustment time were the dependent variables. Final MARRs were relatively lower during the first few exposure days (14 - 15 repetitions/min) and increased for days 5 - 7 (16 - 18 repetitions/min). On average participants made four adjustments to reach MARR . Day was not found to significantly affect MARR, though week affected both MARR and adjustment time. Thus, an exposure of two weeks may be needed to obtain stable and valid psychophysical limits for manual torquing and, perhaps, related tasks.","abstract_html":"Repetitive and forceful exertions have been dentified as an important risk factor for occupational injuries. One method used to determine appropriate exposures to these and other risk factors is psychophysics, which is based on individual perceptions of task demands and/or risk. Effects of work exposure have been indicated as of potential importance, but have not been well studied. Indications from an earlier study related to psychophysical limits for a repetitive manual torquing task were that five days of work conditioning had minimal effects on resulting Maximum Acceptable Repetition Rates (MARR). However, it is unknown whether and how longer work exposure durations might influence MARRs. The current study investigated the effects of work exposure on MARR and adjustment time over 10 working days (two weeks) with two days of rest after five days. Ten participants (five males and five females) performed a manual torquing (45 Nm load) task at mid-chest level in the coronal plane for a one hour test session. Starting repetition rate for each participant was set at single high and low rate on alternate days. Temporal (exposure) effects were determined, where day of exposure was the independent variable, and MARR and adjustment time were the dependent variables. Final MARRs were relatively lower during the first few exposure days (14 - 15 repetitions/min) and increased for days 5 - 7 (16 - 18 repetitions/min). On average participants made four adjustments to reach MARR . Day was not found to significantly affect MARR, though week affected both MARR and adjustment time. Thus, an exposure of two weeks may be needed to obtain stable and valid psychophysical limits for manual torquing and, perhaps, related tasks.","abstract_has_math":false,"creators":["Kant, Ravi"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Industrial and Systems Engineering","degree_department":"Industrial and Systems Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Nussbaum, Maury A."],"committee_members":["Babski-Reeves, Kari L.","Kleiner, Brian M."],"year":2006,"date_issued":"2006-12-11","date_published":"2006-12-11","updated_at":"2026-07-22T22:19:47Z","subjects":["Work Exposure","Maximum Acceptable Repetition Rate (MARR)","Ratings of Perceived Exertion (RPE)","Manual Torquing Task (MTT)","Psychophysics"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-07312007-111030"],"render_values":[{"text":"etd-07312007-111030","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/34277","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Nussbaum, Maury A."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Babski-Reeves, Kari L.","Kleiner, Brian M."]},{"key":"dc:contributor.department","label":"Department","values":["Industrial and Systems Engineering"]},{"key":"dc:creator","label":"Author","values":["Kant, Ravi"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:42:21Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:42:21Z","2007-08-30"]},{"key":"dc:date.issued","label":"Date","values":["2006-12-11"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Industrial and Systems Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Work Exposure","Maximum Acceptable Repetition Rate (MARR)","Ratings of Perceived Exertion (RPE)","Manual Torquing Task (MTT)","Psychophysics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-07312007-111030"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/34277"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Repetitive and forceful exertions have been dentified as an important risk factor for occupational injuries. One method used to determine appropriate exposures to these and other risk factors is psychophysics, which is based on individual perceptions of task demands and/or risk. Effects of work exposure have been indicated as of potential importance, but have not been well studied. Indications from an earlier study related to psychophysical limits for a repetitive manual torquing task were that five days of work conditioning had minimal effects on resulting Maximum Acceptable Repetition Rates (MARR). However, it is unknown whether and how longer work exposure durations might influence MARRs. The current study investigated the effects of work exposure on MARR and adjustment time over 10 working days (two weeks) with two days of rest after five days. Ten participants (five males and five females) performed a manual torquing (45 Nm load) task at mid-chest level in the coronal plane for a one hour test session. Starting repetition rate for each participant was set at single high and low rate on alternate days. Temporal (exposure) effects were determined, where day of exposure was the independent variable, and MARR and adjustment time were the dependent variables. Final MARRs were relatively lower during the first few exposure days (14 - 15 repetitions/min) and increased for days 5 - 7 (16 - 18 repetitions/min). On average participants made four adjustments to reach MARR . Day was not found to significantly affect MARR, though week affected both MARR and adjustment time. Thus, an exposure of two weeks may be needed to obtain stable and valid psychophysical limits for manual torquing and, perhaps, related tasks."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Effects of Work Exposure on Maximum Acceptable Repetition Rates in a Manual Torquing Task"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Nussbaum, Maury A."],"dc:contributor.committeemember":["Babski-Reeves, Kari L.","Kleiner, Brian M."],"dc:contributor.department":["Industrial and Systems Engineering"],"dc:creator":["Kant, Ravi"],"dc:date.accessioned":["2014-03-14T20:42:21Z"],"dc:date.available":["2014-03-14T20:42:21Z","2007-08-30"],"dc:date.issued":["2006-12-11"],"dc:description.abstract":["Repetitive and forceful exertions have been dentified as an important risk factor for occupational injuries. One method used to determine appropriate exposures to these and other risk factors is psychophysics, which is based on individual perceptions of task demands and/or risk. Effects of work exposure have been indicated as of potential importance, but have not been well studied. Indications from an earlier study related to psychophysical limits for a repetitive manual torquing task were that five days of work conditioning had minimal effects on resulting Maximum Acceptable Repetition Rates (MARR). However, it is unknown whether and how longer work exposure durations might influence MARRs. The current study investigated the effects of work exposure on MARR and adjustment time over 10 working days (two weeks) with two days of rest after five days. Ten participants (five males and five females) performed a manual torquing (45 Nm load) task at mid-chest level in the coronal plane for a one hour test session. Starting repetition rate for each participant was set at single high and low rate on alternate days. Temporal (exposure) effects were determined, where day of exposure was the independent variable, and MARR and adjustment time were the dependent variables. Final MARRs were relatively lower during the first few exposure days (14 - 15 repetitions/min) and increased for days 5 - 7 (16 - 18 repetitions/min). On average participants made four adjustments to reach MARR . Day was not found to significantly affect MARR, though week affected both MARR and adjustment time. Thus, an exposure of two weeks may be needed to obtain stable and valid psychophysical limits for manual torquing and, perhaps, related tasks."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-07312007-111030"],"dc:identifier.uri":["http://hdl.handle.net/10919/34277"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Work Exposure","Maximum Acceptable Repetition Rate (MARR)","Ratings of Perceived Exertion (RPE)","Manual Torquing Task (MTT)","Psychophysics"],"dc:title":["Effects of Work Exposure on Maximum Acceptable Repetition Rates in a Manual Torquing Task"],"dc:type":["Thesis"],"thesis:degree_discipline":["Industrial and Systems Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:47Z"}