title: Effective and selective stretching of the medial head of the gastrocnemius.
abstract: Muscle injury frequently occurs in the medial head of the gastrocnemius (MG), and stretching is used for treatment. However, there are no studies based on anatomical considerations and biomechanics. This study therefore examined the macroscopic anatomical structure of the triceps surae muscle to design an effective and selective MG stretching method, before quantitatively verifying that method by ultrasonography. The macroscopic anatomy was analyzed in 16 Japanese cadavers (25 legs). Based on the anatomical findings and the arrangement of fascicles in the MG, we concluded that ankle inversion might be advantageous for selective stretching of the tendon fiber bundles into which the MG inserts. We devised a method in which the limb was initially positioned with the knee joint in extension and the ankle joint in plantar flexion. Then, the ankle was dorsiflexed and inverted. The proposed method was compared with standard stretching and verified by ultrasonography in eight healthy adult males. This method effectively and selectively stretched the MG, producing a significantly decreased pennation angle and increased muscle fiber length. This method may be beneficial for preventing future injuries and may enhance the effect of therapy on the MG.
authors.affiliation: Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, Japan; Department of Anatomy, School of Life Dentistry at Niigata, Nippon Dental University, Niigata, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Edama
authors.forename: H
authors.initials: H
authors.lastname: Onishi
authors.forename: K
authors.initials: K
authors.lastname: Kumaki
authors.forename: I
authors.initials: I
authors.lastname: Kageyama
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: S
authors.initials: S
authors.lastname: Nashimoto
mesh_terms: D000125:Achilles Tendon / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology; D000328:Adult; D001696:Biomechanical Phenomena; D004576:Electromyography; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007866:Leg / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D052580:Muscle Stretching Exercises / Q000379:methods*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology*; D011897:Random Allocation; D015203:Reproducibility of Results; D014463:Ultrasonography
keywords: Achilles tendon; triceps surae muscle; ultrasonography