Automatic tracking of medial gastrocnemius fascicle length during human locomotion

Cronin, Neil J., Carty, Christopher P., Barrett, Rod S. and Lichtwark, Glen (2011) Automatic tracking of medial gastrocnemius fascicle length during human locomotion. Journal of Applied Physiology, 111 5: 1491-1496. doi:10.1152/japplphysiol.00530.2011

Author Cronin, Neil J.
Carty, Christopher P.
Barrett, Rod S.
Lichtwark, Glen
Title Automatic tracking of medial gastrocnemius fascicle length during human locomotion
Journal name Journal of Applied Physiology   Check publisher's open access policy
ISSN 8750-7587
Publication date 2011-11-01
Year available 2011
Sub-type Article (original research)
DOI 10.1152/japplphysiol.00530.2011
Open Access Status Not yet assessed
Volume 111
Issue 5
Start page 1491
End page 1496
Total pages 6
Place of publication Bethesda, MD, United States
Publisher American Physiological Society
Language eng
Abstract During human locomotion lower extremity muscle-tendon units undergo cyclic length changes that were previously assumed to be representative of muscle fascicle length changes. Measurements in cats and humans have since revealed that muscle fascicle length changes can be uncoupled from those of the muscle-tendon unit. Ultrasonography is frequently used to estimate fascicle length changes during human locomotion. Fascicle length analysis requires time consuming manual methods that are prone to human error and experimenter bias. To bypass these limitations, we have developed an automatic fascicle tracking method based on the Lucas-Kanade optical flow algorithm with an affine optic flow extension. The aims of this study were to compare gastrocnemius fascicle length changes during locomotion using the automated and manual approaches and to determine the repeatability of the automated approach. Ultrasound was used to examine gastrocnemius fascicle lengths in eight participants walking at 4, 5, 6, and 7 km/h and jogging at 7 km/h on a treadmill. Ground reaction forces and three dimensional kinematics were recorded simultaneously. The level of agreement between methods and the repeatability of the automated method were quantified using the coefficient of multiple correlation (CMC). Regardless of speed, the level of agreement between methods was high, with overall CMC values of 0.90 ± 0.09 (95% CI: 0.86–0.95). Repeatability of the algorithm was also high, with an overall CMC of 0.88 ± 0.08 (95% CI: 0.79–0.96). The automated fascicle tracking method presented here is a robust, reliable, and time-efficient alternative to the manual analysis of muscle fascicle length during gait.
Keyword Ultrasonography
Affine flow
Muscle fascicle
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2012 Collection
School of Human Movement and Nutrition Sciences Publications
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