<abstract xmlns="http://www.w3.org/1999/xhtml">Study aim: the aim of our study was to evaluate electromyography (EMG) activity in exercises where the load to the muscles is determined by the external torque. In a part of the exercises, we changed the value of the external force, while in the other we modified the length of the lever arm at which the force was applied.
Material and methods: the study was carried out on a group of 12 subjects (21 ± 2 years, 61 ± 4.8 mass, 172 ± 5 cm height). Electromyographic activity of the rectus abdominis (RA) muscle was evaluated by recording the EMG signal. The length of the lever arm of the external force was changed by using four different positions of the upper limbs, whereas the magnitude of the external force was changed through adding the weights of 0.5, 1.0, and 1.5 kg. The data recorded were normalized with respect to EMG activity measured under maximum voluntary contraction (MVC) conditions.
Results: it was found that the change of the lever arm at which the force was applied (any change in the position of the upper limbs) causes a change in EMG activity in each part of the RA muscle from ca. 50% to ca. 100% MVC (p &lt; 0.001). Further, the change in the external load changes statistically significantly the EMG activity only in the left upper part of the RA muscle (p &lt; 0.05).
Conclusions: activity in the RA muscle that increased for longer lever arms of the external force, offers opportunities for changing the load used during the exercise in a manner that is safe for the vertebral column.</abstract>

Study aim: the aim of our study was to evaluate electromyography (EMG) activity in exercises where the load to the muscles is determined by the external torque. In a part of the exercises, we changed the value of the external force, while in the other we modified the length of the lever arm at which the force was applied.
Material and methods: the study was carried out on a group of 12 subjects (21 ± 2 years, 61 ± 4.8 mass, 172 ± 5 cm height). Electromyographic activity of the rectus abdominis (RA) muscle was evaluated by recording the EMG signal. The length of the lever arm of the external force was changed by using four different positions of the upper limbs, whereas the magnitude of the external force was changed through adding the weights of 0.5, 1.0, and 1.5 kg. The data recorded were normalized with respect to EMG activity measured under maximum voluntary contraction (MVC) conditions.
Results: it was found that the change of the lever arm at which the force was applied (any change in the position of the upper limbs) causes a change in EMG activity in each part of the RA muscle from ca. 50% to ca. 100% MVC (p < 0.001). Further, the change in the external load changes statistically significantly the EMG activity only in the left upper part of the RA muscle (p < 0.05).
Conclusions: activity in the RA muscle that increased for longer lever arms of the external force, offers opportunities for changing the load used during the exercise in a manner that is safe for the vertebral column.

External torque as a factor to modify load in abdominal curl-up exercises

Department of Biomechanics, University School of Physical Education, Wroclaw, Poland

Biomedical Human Kinetics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"External torque as a factor to modify load in abdominal curl-up exercises"}

Study aim: the aim of our study was to evaluate electromyography (EMG) activity in exercises where the load to the muscles is determined by the external...

External torque as a factor to modify load in abdominal curl-up exercises

Published Online: Mar 19, 2015

Page range: -

DOI: https://doi.org/10.1515/bhk-2015-0003

Keywords
EMG, external torque, prevention of LBP

© University of Physical Education, Warsaw, Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

External torque as a factor to modify load in abdominal curl-up exercises

Published Online: Mar 19, 2015

Page range: -

DOI: https://doi.org/10.1515/bhk-2015-0003

KeywordsEMG, external torque, prevention of LBP

© University of Physical Education, Warsaw, Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
EMG, external torque, prevention of LBP