title: Morphological classification of the anterior and middle talocalcaneal joints in terms of biomechanical stress dispersion.
abstract: Of the various foot joints, the level of interest shown in the talocalcaneal joint has been notably low. However, when considering stress dispersion during bipedal locomotion, the talocalcaneal joint plays an important role. Present study examined and morphologically classified the talocalcaneal joint. The present study investigated the morphology of the anterior talocalcaneal articular surface (A) and middle talocalcaneal articular surface (M) of the calcaneus. Using 94 feet of 47 human cadavers for anatomical dissection, the morphology of the A and M was classified into the following 6 types: Type 1, double ellipsoid, and A is markedly smaller than M; Type 2, gourd-form, and A is markedly smaller than M; Type 3, double ellipsoid, but A and M are partially in contact, Type 4, double ellipsoid, A and M are completely separated; Type 5, cylinder-form; and Type 6, others. Types 4 and 5 accounted for the majority of cases. In upright standing and bipedal locomotion, the anterior and middle talocalcaneal joints receive the anterior component of body weight dispersion in the posterior foot region. Morphological classification of articular surfaces that actually bear body weight is important, reflecting the degree of stress dispersion.
authors.affiliation: Department of Anatomy, Faculty of Medicine, Kyorin University, 20-2 Shinkawa 6, Mitaka city, Tokyo 181-8611, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Shiraishi
authors.forename: George
authors.initials: G
authors.lastname: Matsumura
authors.forename: Akihito
authors.initials: A
authors.lastname: Uehara
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001835:Body Weight / Q000502:physiology; D004210:Dissection; D006801:Humans; D008252:Macaca fascicularis; D013380:Subtalar Joint / Q000033:anatomy & histology* / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology