Related Experiment Video
Updated: Jun 22, 2026
08:40
Quantifying Arms and Legs Contributions during Repetitive Electrically-Assisted Sit-To-Stand Exercise in Paraplegics: A Pilot Study
Published on: November 11, 2022
Variation in limb support influences the time to task failure for a postural contraction
Tejin Yoon1, Rachel Hawe, Sandra K Hunter
1Exercise Science Program, Department of Physical Therapy, Marquette University, Milwaukee, WI 53201, USA.
Journal of Motor Behavior
|June 2, 2009
Summary
Supporting the foot during prolonged dorsiflexor muscle contractions significantly increases time to task failure. This finding highlights the importance of limb support in reducing muscle fatigability and altering muscle activation patterns.
Area of Science:
- Biomechanics
- Exercise Physiology
- Muscle Physiology
Background:
- Sustained submaximal contractions can lead to muscle fatigue.
- The role of external support in modulating muscle fatigue during isometric tasks is not fully understood.
Purpose of the Study:
- To compare time to task failure and muscle activation for dorsiflexor muscles under supported versus unsupported conditions during a sustained isometric position task.
Main Methods:
- Participants performed a sustained isometric position task with an inertial load (20% of maximal torque) until task failure.
- Two conditions were tested: supported foot position and unsupported foot position.
- Electromyography (EMG) of the tibialis anterior muscle was recorded.
Main Results:
- Time to task failure was significantly longer in the supported condition (15.4 min) compared to the unsupported condition (10.0 min).
- Muscle activation patterns of the tibialis anterior differed significantly between the supported and unsupported tasks.
- Increased foot support led to decreased muscle fatigability.
Conclusions:
- Providing external support to the foot during prolonged dorsiflexor activation reduces muscle fatigability.
- Limb support influences muscle activation strategies and prolongs endurance.
- These findings underscore the importance of considering limb support to minimize fatigue during demanding tasks.
