title: Torque patterns of the limbs of small therian mammals during locomotion on flat ground.
abstract: In three species of small therian mammals (Scandentia: Tupaia glis, Rodentia: Galea musteloides and Lagomorpha: Ochotona rufescens) the net joint forces and torques acting during stance phase in the four kinematically relevant joints of the forelimbs (scapular pivot, shoulder joint, elbow joint, wrist joint) and the hindlimbs (hip joint, knee joint, ankle joint, intratarsal joint) were determined by inverse dynamic analysis. Kinematics were measured by cineradiography (150 frames s(-1)). Synchronously ground reaction forces were acquired by forceplates. Morphometry of the extremities was performed by a scanning method using structured illumination. The vector sum of ground reaction forces and weight accounts for most of the joint force vector. Inertial effects can be neglected since errors of net joint forces amount at most to 10 %. The general time course of joint torques is comparable for all species in all joints of the forelimb and in the ankle joint. Torques in the intratarsal joints differ between tailed and tail-less species. The torque patterns in the knee and hip joint are unique to each species. For the first time torque patterns are described completely for the forelimb including the scapula as the dominant propulsive segment. The results are compared with the few torque data available for various joints of cats (Felis catus), dogs (Canis lupus f. familiaris), goats (Capra sp.) and horses (Equus przewalskii f. caballus).
authors.affiliation: Institut für Spezielle Zoologie und Evolutionsbiologie, Friedrich-Schiller-Universität Jena, Erbertstrasse 1, D-07743 Jena, Germany.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Witte
authors.forename: Jutta
authors.initials: J
authors.lastname: Biltzinger
authors.forename: Rémi
authors.initials: R
authors.lastname: Hackert
authors.forename: Nadja
authors.initials: N
authors.lastname: Schilling
authors.forename: Manuela
authors.initials: M
authors.lastname: Schmidt
authors.forename: Christian
authors.initials: C
authors.lastname: Reich
authors.forename: Martin S
authors.initials: MS
authors.lastname: Fischer
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002933:Cineradiography; D005121:Extremities / Q000033:anatomy & histology / Q000502:physiology*; D005552:Forelimb / Q000033:anatomy & histology / Q000502:physiology; D006168:Guinea Pigs / Q000033:anatomy & histology / Q000502:physiology; D006614:Hindlimb / Q000033:anatomy & histology / Q000502:physiology; D007793:Lagomorpha / Q000033:anatomy & histology / Q000502:physiology; D008124:Locomotion / Q000502:physiology; D008322:Mammals / Q000033:anatomy & histology / Q000502:physiology*; D016675:Scandentia / Q000033:anatomy & histology / Q000502:physiology; D019415:Torque