TY - JOUR
T1 - The use of biomechanical measures in the investigation of changes in lifting strategies over extended periods
AU - Fogleman, Maxwell
AU - Smith, James L.
PY - 1995/7
Y1 - 1995/7
N2 - The experiment presented here was conducted for the purpose of investigating changes in lifting patterns that occur due to the effects of learning and due to the effects of lifting over extended periods. It also illustrated the use of biomechanical measures in tracking these changes. Biomechanical measures usually have not been used to make interences about changes in lifting patterns due to such effects as practice, the number of lifts performed in a session, the frequency of lifting, etc. Six inexperienced subjects were asked to lift for an initial 4-hour session, six half-hour practice sessions, and a final 4-hour lifting session. All lifts were conducted at the rate of one lift per minute, from floor to shoulder height, with a weight chosen by the subject. Results indicated that there is a change from a leg lift to a more biomechanically stressful back lift (as inferred from greater joint center moments) due to the effects of training, but once these effects are observed they were maintained through the second 4-hour session. Furthermore, reduction in time per lift over the course of the experiment was accompanied by increases in moments at all of the joint centers, but this was more pronounced in the hip and knee joints for half of the subjects. Conclusions to be drawn from these results are that biomechanical modeling can be used under such circumstances with meaningful results and that there is a natural tendency to lift more quickly and to shift moments to the stronger muscles in the process of learning lifting patterns.
AB - The experiment presented here was conducted for the purpose of investigating changes in lifting patterns that occur due to the effects of learning and due to the effects of lifting over extended periods. It also illustrated the use of biomechanical measures in tracking these changes. Biomechanical measures usually have not been used to make interences about changes in lifting patterns due to such effects as practice, the number of lifts performed in a session, the frequency of lifting, etc. Six inexperienced subjects were asked to lift for an initial 4-hour session, six half-hour practice sessions, and a final 4-hour lifting session. All lifts were conducted at the rate of one lift per minute, from floor to shoulder height, with a weight chosen by the subject. Results indicated that there is a change from a leg lift to a more biomechanically stressful back lift (as inferred from greater joint center moments) due to the effects of training, but once these effects are observed they were maintained through the second 4-hour session. Furthermore, reduction in time per lift over the course of the experiment was accompanied by increases in moments at all of the joint centers, but this was more pronounced in the hip and knee joints for half of the subjects. Conclusions to be drawn from these results are that biomechanical modeling can be used under such circumstances with meaningful results and that there is a natural tendency to lift more quickly and to shift moments to the stronger muscles in the process of learning lifting patterns.
KW - Biomechanics
KW - Forward dynamics
KW - Inverse dynamics
KW - Kinematics
KW - Kinetics
KW - Moments
UR - http://www.scopus.com/inward/record.url?scp=0029065367&partnerID=8YFLogxK
U2 - 10.1016/0169-8141(94)00087-J
DO - 10.1016/0169-8141(94)00087-J
M3 - Article
AN - SCOPUS:0029065367
SN - 0169-8141
VL - 16
SP - 57
EP - 71
JO - International Journal of Industrial Ergonomics
JF - International Journal of Industrial Ergonomics
IS - 1
ER -