Abstract
The gastrocnemius has been viewed as an important contributor at the knee joint as a joint flexor and stabilizer across all the knee and ankle joint angles. The purpose of this study was to investigate the influence of knee and ankle joint angles on the knee flexor function of the gastrocnemius. Seventeen participants were tested on a Biodex dynamometer with the gastrocnemius muscle selectively stimulated at a standardized level of electrical current. The results indicated that both ankle and knee joint angle influence the knee joint flexion moment produced by the gastrocnemius. Further analysis revealed that the flexion moment was greatest with the knee joint straight (180°) across all ankle joint angles. The greatest reduction in knee flexion moment occurred between 180 and 165° of knee angle. No significant difference was observed in the knee flexion moment between 165° and 115° knee flexion, and little knee flexion moment was observed at knee angles of 90° and 75°. The dramatic reduction of moment between 180° and 165° knee angle is possibly due to the change of moment arm while the little moment production during extreme flexion (90° and 75°) may be due to the reduction of muscle length.
| Original language | English |
|---|---|
| Pages (from-to) | 385-390 |
| Number of pages | 6 |
| Journal | Journal of Electromyography and Kinesiology |
| Volume | 12 |
| Issue number | 5 |
| DOIs | |
| State | Published - Oct 2002 |
Scopus Subject Areas
- Neuroscience (miscellaneous)
- Biophysics
- Clinical Neurology
Keywords
- Functional electrical stimulation
- Gastrocnemius
- Joint moment
- Muscle mechanics