Forelimb: A front limb of a quadruped. (The Random House College Dictionary, 1980)Hindlimb: Either of two extremities of four-footed non-primate land animals. It usually consists of a FEMUR; TIBIA; and FIBULA; tarsals; METATARSALS; and TOES. (From Storer et al., General Zoology, 6th ed, p73)Locomotion: Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.Extremities: The farthest or outermost projections of the body, such as the HAND and FOOT.Anatomy, Comparative: The comparative study of animal structure with regard to homologous organs or parts. (Stedman, 25th ed)Motor Cortex: Area of the FRONTAL LOBE concerned with primary motor control located in the dorsal PRECENTRAL GYRUS immediately anterior to the central sulcus. It is comprised of three areas: the primary motor cortex located on the anterior paracentral lobule on the medial surface of the brain; the premotor cortex located anterior to the primary motor cortex; and the supplementary motor area located on the midline surface of the hemisphere anterior to the primary motor cortex.Limb Buds: Distinct regions of mesenchymal outgrowth at both flanks of an embryo during the SOMITE period. Limb buds, covered by ECTODERM, give rise to forelimb, hindlimb, and eventual functional limb structures. Limb bud cultures are used to study CELL DIFFERENTIATION; ORGANOGENESIS; and MORPHOGENESIS.Ulna: The inner and longer bone of the FOREARM.Pyramidal Tracts: Fibers that arise from cells within the cerebral cortex, pass through the medullary pyramid, and descend in the spinal cord. Many authorities say the pyramidal tracts include both the corticospinal and corticobulbar tracts.Lameness, Animal: A departure from the normal gait in animals.Red Nucleus: A pinkish-yellow portion of the midbrain situated in the rostral mesencephalic tegmentum. It receives a large projection from the contralateral half of the CEREBELLUM via the superior cerebellar peduncle and a projection from the ipsilateral MOTOR CORTEX.Carpus, Animal: The region corresponding to the human WRIST in non-human ANIMALS.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.Notophthalmus viridescens: A species of newt in the Salamandridae family in which the larvae transform into terrestrial eft stage and later into an aquatic adult. They occur from Canada to southern United States. Viridescens refers to the greenish color often found in this species.Scandentia: An order of the class MAMMALS that consists of one family, TUPAIIDAE (tree shrews), 5 genera (one of which is TUPAIA), and 16 species. Their recent distribution is from India to the Philippines, southern China to Java, Borneo, Sumatra, Bali, and other islands in those regions.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Limb Deformities, Congenital: Congenital structural deformities of the upper and lower extremities collectively or unspecified.Somatosensory Cortex: Area of the parietal lobe concerned with receiving sensations such as movement, pain, pressure, position, temperature, touch, and vibration. It lies posterior to the central sulcus.Cats: The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)Sloths: Slow-moving exclusively arboreal mammals that inhabit the tropical forests of South and Central America.Salamandridae: A family of Urodela consisting of 15 living genera and about 42 species and occurring in North America, Europe, Asia, and North Africa.Electromyography: Recording of the changes in electric potential of muscle by means of surface or needle electrodes.Humerus: Bone in humans and primates extending from the SHOULDER JOINT to the ELBOW JOINT.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Functional Laterality: Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.Dinosaurs: General name for two extinct orders of reptiles from the Mesozoic era: Saurischia and Ornithischia.Muscle, Skeletal: A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.Musculoskeletal Development: The morphologic and physiological changes of the MUSCLES, bones (BONE AND BONES), and CARTILAGE of the body, i.e., MUSCULOSKELETAL SYSTEM, during the prenatal and postnatal stages of development.Recovery of Function: A partial or complete return to the normal or proper physiologic activity of an organ or part following disease or trauma.Efferent Pathways: Nerve structures through which impulses are conducted from a nerve center toward a peripheral site. Such impulses are conducted via efferent neurons (NEURONS, EFFERENT), such as MOTOR NEURONS, autonomic neurons, and hypophyseal neurons.Saimiri: A genus of the family CEBIDAE consisting of four species: S. boliviensis, S. orstedii (red-backed squirrel monkey), S. sciureus (common squirrel monkey), and S. ustus. They inhabit tropical rain forests in Central and South America. S. sciureus is used extensively in research studies.Behavior, Animal: The observable response an animal makes to any situation.Fossils: Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.Bones of Upper Extremity: The bones of the upper and lower ARM. They include the CLAVICLE and SCAPULA.Motor Activity: The physical activity of a human or an animal as a behavioral phenomenon.Motor Skills: Performance of complex motor acts.Felidae: The cat family in the order CARNIVORA comprised of muscular, deep-chested terrestrial carnivores with a highly predatory lifestyle.Spinal Cord: A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.Spinal Cord Stimulation: Application of electric current to the spine for treatment of a variety of conditions involving innervation from the spinal cord.Rats, Long-Evans: An outbred strain of rats developed in 1915 by crossing several Wistar Institute white females with a wild gray male. Inbred strains have been derived from this original outbred strain, including Long-Evans cinnamon rats (RATS, INBRED LEC) and Otsuka-Long-Evans-Tokushima Fatty rats (RATS, INBRED OLETF), which are models for Wilson's disease and non-insulin dependent diabetes mellitus, respectively.Radius: The outer shorter of the two bones of the FOREARM, lying parallel to the ULNA and partially revolving around it.T-Box Domain Proteins: Proteins containing a region of conserved sequence, about 200 amino acids long, which encodes a particular sequence specific DNA binding domain (the T-box domain). These proteins are transcription factors that control developmental pathways. The prototype of this family is the mouse Brachyury (or T) gene product.