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Updated: Jun 5, 2026

The Impact of Motor Task Conditions on Goal-Directed Arm Reaching Kinematics and Trunk Compensation in Chronic Stroke Survivors
Published on: May 2, 2021
Time to task failure of trunk extensor muscles differs with load type
James S Thomas1, Andrew J Ross, David W Russ
1School of Rehabilitation and Communication Sciences, Division of Physical Therapy, Ohio University, Athens 45701, USA. thomasj5@ohiou.edu
Abstract:
Time to task failure of trunk extensor muscles during seated submaximal isometric exertions was assessed in 18 healthy participants using 2 different load types. One required supporting an inertial load (position-matching task) whereas the 2nd required maintaining an equivalent torque against a rigid restraint (force-matching task). Time to task failure was significantly longer for position-matching tasks compared to the force-matching tasks. This finding is opposite to that reported for the appendicular muscles. A subset of 4 individuals completed a 2nd experiment to test the time to task failure of the elbow flexors in the position- and force-matching tasks. Time to task failure of the elbow flexors was significantly longer for the force-matching tasks compared to position matching. Thus, the same population shows that the effects of load type on time to task failure are opposite for the appendicular and axial muscles. This could be an important issue in understanding the mechanisms of task failure, and the endurance capacity of the trunk extensor muscles.
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