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The online version of this article (doi:10.1186/1757-1146-7-26) contains supplementary material, which is available to authorized users.
Toshiyuki Kurihara, Junichiro Yamauchi contributed equally to this work.
All the authors have no competing of interest to disclose.
TK and JY conceived and designed the experiments. TK, JY, MO, and NT performed the experiments and analyzed the data. TK, JY and TI contributed materials/analysis tools. TK, JY, MO, TH, and TI drafted the manuscript. All authors read and approved the final manuscript.
The aims of this study were to investigate the relationships between the maximum isometric toe flexor muscle strength (TFS) and cross-sectional area (CSA) of the plantar intrinsic and extrinsic muscles and to identify the major determinant of maximum TFS among CSA of the plantar intrinsic and extrinsic muscles.
Twenty six young healthy participants (14 men, 12 women; age, 20.4 ± 1.6 years) volunteered for the study. TFS was measured by a specific designed dynamometer, and CSA of plantar intrinsic and extrinsic muscles were measured using magnetic resonance imaging (MRI). To measure TFS, seated participants optimally gripped the bar with their toes and exerted maximum force on the dynamometer. For each participant, the highest force produced among three trials was used for further analysis. To measure CSA, serial T1-weighted images were acquired.
TFS was significantly correlated with CSA of the plantar intrinsic and extrinsic muscles. Stepwise multiple linear regression analyses identified that the major determinant of TFS was CSA of medial parts of plantar intrinsic muscles (flexor hallucis brevis, flexor digitorum brevis, quadratus plantae, lumbricals and abductor hallucis). There was no significant difference between men and women in TFS/CSA.
CSA of the plantar intrinsic and extrinsic muscles is one of important factors for determining the maximum TFS in humans.
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- Maximum toe flexor muscle strength and quantitative analysis of human plantar intrinsic and extrinsic muscles by a magnetic resonance imaging technique
- BioMed Central