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Differentiation of submaximal from maximal trunk extension effort: an isokinetic study using a new testing protocol
1Department of Physical Therapy, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
Spine
|December 17, 1997
Summary
This study found that the difference in speed between concentric and eccentric contractions effectively distinguishes maximal from submaximal trunk extension effort in healthy individuals. This method aids in assessing genuine maximal effort during testing.
Area of Science:
- Biomechanics
- Human Movement Analysis
- Exercise Physiology
Background:
- Previous research has struggled to identify submaximal effort in trunk extension using isokinetic dynamometry.
- Consistency-related parameters have not reliably differentiated maximal from submaximal trunk extension efforts.
Purpose of the Study:
- To identify quantitative parameters from isokinetic dynamometry that can differentiate submaximal from maximal trunk extension effort.
- To evaluate the relationship between concentric and eccentric contractions of trunk extensors at varying effort levels.
Main Methods:
- Twenty healthy adults (12 men, 8 women) performed maximal, 50% maximal, and best reproducible effort trunk extensions.
- Testing involved intermittent concentric and eccentric contractions at 20 and 60 degrees/second.
- Isokinetic dynamometry was used to measure trunk extension moment.
Main Results:
- The difference in velocity between concentric and eccentric contractions demonstrated the highest power in differentiating effort levels (P < 0.0001).
- This intervelocity difference proved effective in distinguishing between maximal and submaximal trunk extension efforts.
Conclusions:
- The developed protocol successfully differentiates submaximal from maximal trunk extension effort in healthy subjects.
- The intervelocity difference in contractions is a key parameter for assessing effort exertion.