Movement of loads with trunk rotation
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Updated: Apr 17, 2026

Method to Measure Tone of Axial and Proximal Muscle
Published on: December 14, 2011
Errol R Hoffmann1, Alan H S Chan
1a Department of Systems Engineering and Engineering Management , City University of Hong Kong , Kowloon Tong , Hong Kong.
Abstract:
Movements with participants standing at a bench and moving loads up to 6 kg were studied, with participants using two hands to hold the load and trunk rotation in order to move the loads to specified locations. Tasks were performed with rapid ballistic movements and also with ongoing visual control. Data for ballistic movements were modelled in terms of a modified form of the (Gan, K.-C. and Hoffmann, E.R. 1988. "Geometrical conditions for ballistic and visually controlled movements." Ergonomics 5 (31): 829-839) model for ballistic movements, taking into account the inertial properties of trunk rotation. Visually-controlled movements were modelled in terms of Fitts' law and a term that allowed for the ballistic form of the first submovement of the visually-controlled movement. Practitioner Summary: Movement times to move masses up to 6 kg, for workers at a bench using trunk rotation, are given. Theoretical models fit the experimental data very well and allow prediction of movement times.
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