Biomechanics - Body Movements Assignment Example | Topics and Well Written Essays - 1000 words

Biomechanics - Body Movements - Assignment Example The two muscles are antagonistic to each other. The biceps brings about flexion while the triceps is responsible for extension of the upper arm. The upper end of the biceps has its origin from the scapula and its lower end is inserted on the radius bone lying on the medial aspect of the forearm. The muscle is located in the front portion of the forearm. Contraction of biceps brachii in response to nervous stimulation causes flexion i.e. the forearm is raised in an upward movement. The muscle is therefore categorized as a flexor muscle. In response to the flexion, i.e. when the biceps contracts, the antagonistic triceps muscle relaxes simultaneously. The triceps is located in the posterior portion of the upper arm with its origin from the scapula as well as the humerus bones. The point of insertion of triceps is at the olecranon process of the ulna, the long bone in the forearm located on the lateral side. Contraction of the triceps straightens or extends the arm and this is the reaso n for its classification as an extensor muscle. The movement follows the pattern of a lever of the third order, wherein the load is located at the hand, and the fulcrum at the elbow (Peterson & Bronzino, 2008). 2) In no more than 250 words describe the function of the skeleton and its importance in movement. The human skeleton is an integrated framework of 206 bones which supports the soft tissue and protects the vital organs (McKinley & O’Loughlin, 2008). The skeletal system has been classified as the axial skeleton, comprising of the bones lying along the central axis of the body, which includes the skull, the vertebral column and the rib cage; and the appendicular skeleton, comprising the bones of the arms and legs, as well as the pelvic and the pectoral girdles (McKinley & O’Loughlin, 2008). The appendicular skeleton is more pertinent as far as the body movements are concerned although the axial skeleton is by no means non-contributory, as it provides the central a xis or the pivot around which the body movements occur. The mandible is the mobile portion in the skull and the vertebrae too glide to a certain extent to impart flexibility to the vertebral column. The appendicular skeleton however shows a great degree of motility and is responsible for locomotion. The upper and the lower limbs emanate from the pectoral and the pelvic girdle respectively while the ribs form a bony cage to protect the vital organs. The skeleton provides the hard, bony framework for the origin as well as insertion of the skeletal muscles, the contraction and relaxation of which is actually responsible for locomotion. The skeletal muscles are highly specialized and often occur in pairs to produce movement antagonistic to each other. The movement of the joints can vary from simple gliding, rotation, adduction, abduction, flexion and extension. The muscles are firmly attached to the bones through specialized structures called ligaments and tendons and movements occur in the form of levers of the 1st, 2nd and the 3rd order. 3) In no more than 250 words describe and provide examples of each synovial joint. Synovial joints are freely mobile articulations in which the participating bones are separated by a space called joint cavity (McKinley & O’Loughlin, 2008). These joints are freely mobile and are functionally classified as diarthrosis. There are four synovial joints in the human skeleton viz. the glenohumeral (shoulder) joint; the temporomandibular joint; the elbow, and the knee joint (McKinley & O’