Muscle Moment Arms and Sensitivity Analysis of a Mouse Hindlimb Musculoskeletal Model (Open Access Publisher's Version)
Journal Article - Open Access
ROYAL VETERINARY COLL HATFIELD (UNITED KINGDOM) Hatfield United Kingdom
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Musculoskeletal modelling has become a valuable tool with which to understand how neural, muscular, skeletal and other tissues are integrated to produce movement. Most musculoskeletal modelling work has to date focused on humans or their close relatives, with few examples of quadrupedal animal limb models. A musculoskeletal model of the mouse hind limb could have broad utility for questions in medicine, genetics, locomotion and neuroscience. This is due to this species position as a premier model of human disease, having an array of genetic tools for manipulation of the animal in vivo, and being a small quadruped, a category for which few models exist. Here, the methods used to develop the first three-dimensional 3D model of a mouse hind limb and pelvis are described. The model, which represents bones, joints and 39 musculo-tendon units, was created through a combination of previously gathered muscle architecture data from micro-dissections, contrast enhanced micro-computed tomography CT scanning and digital segmentation. The model allowed muscle moment arms as well as muscle forces to be estimated for each musculo-tendon unit throughout a range of joint rotations. Moment arm analysis supported the reliability of musculo-tendon unit placement within the model, and comparison to a previously published rat hind limb model further supported the models reliability. A sensitivity analysis performed on both the force-generating parameters and muscles attachment points of the model indicated that the maximal isometric muscle moment is generally most sensitive to changes in either tendon slack length or the coordinates of insertion, although the degree to which the moment is affected depends on several factors. This model represents the first step in the creation of a fully dynamic 3D computer model of the mouse hind limb and pelvis that has application to neuromuscular disease, comparative biomechanics and the neuro-mechanical basis of movement.
- Anatomy and Physiology