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Updated: Mar 7, 2026

Isometric and Eccentric Force Generation Assessment of Skeletal Muscles Isolated from Murine Models of Muscular Dystrophies
Published on: January 31, 2013
Improvement in muscle strength with low-load isotonic training depends on fascicle length but not joint angle
Hiroki Tanaka1, Tome Ikezoe2, Masatoshi Nakamura3
1Rehabilitation Unit, Kyoto University Hospital, 54, Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
Introduction:
In this study we investigate whether low-load isotonic training will elicit greater improvement in muscle strength at the same fascicle length, rather than at the same joint angle.
Methods:
Sixteen healthy men (24.1 ± 2.5 years of age) were randomly divided into intervention and control groups. Pre- and posttraining maximum isometric and isokinetic strengths and fascicle lengths of the medial gastrocnemius muscle were measured. Isotonic resistance training at 15 ° to 30 ° ankle plantarflexion at low intensity was conducted for 4 weeks.
Results:
The maximum isometric and isokinetic strength of the intervention group increased significantly only at 15 ° dorsiflexion and 8 ° to 12 ° dorsiflexion. Fascicle length during maximum voluntary contraction at 15 ° dorsiflexion to 0 ° was similar to fascicle length under training conditions.
Discussion:
It is possible that the improvement in muscle strength with low-load training depends on fascicle length rather than joint angle. Muscle Nerve 57: 83-89, 2018.
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