The brachioradialis is a muscle of the forearm that flexes the forearm at the elbow. It is also capable of both pronation and supination, depending on the position of the forearm. It is attached to the distal styloid process of the radius by way of the brachioradialis tendon, and to the lateral supracondylar ridge of the humerus.
The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compartment of the forearm and the associated joints and overlying skin.
The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is most often used to describe the entire appendage of the upper limb, but which in anatomy, technically, means only the region of the upper arm, whereas the lower "arm" is called the forearm. It is homologous to the region of the leg that lies between the knee and the ankle joints, the crus.
The extensor carpi radialis longus is one of the five main muscles that control movements at the wrist. This muscle is quite long, starting on the lateral side of the humerus, and attaching to the base of the second metacarpal bone.
Wrist drop, is a medical condition in which the wrist and the fingers cannot extend at the metacarpophalangeal joints. The wrist remains partially flexed due to an opposing action of flexor muscles of the forearm. As a result, the extensor muscles in the posterior compartment remain paralyzed.
A reflex, or reflex action, is an involuntary and nearly instantaneous movement in response to a stimulus. A reflex is made possible by neural pathways called reflex arcs which can act on an impulse before that impulse reaches the brain. The reflex is then an automatic response to a stimulus that does not receive or need conscious thought.
The radius or radial bone is one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna. The radius is shorter and smaller than the ulna. It is a long bone, prism-shaped and slightly curved longitudinally.
The jaw jerk reflex or the masseter reflex is a stretch reflex used to test the status of a patient's trigeminal nerve and to help distinguish an upper cervical cord compression from lesions that are above the foramen magnum. The mandible—or lower jaw—is tapped at a downward angle just below the lips at the chin while the mouth is held slightly open. In response, the masseter muscles will jerk the mandible upwards. Normally this reflex is absent or very slight. However, in individuals with upper motor neuron lesions the jaw jerk reflex can be quite pronounced.
The posterior interosseous nerve is a nerve in the forearm. It is the continuation of the deep branch of the radial nerve, after this has crossed the supinator muscle. It is considerably diminished in size compared to the deep branch of the radial nerve. The nerve fibers originate from cervical segments C7 and C8.
The Galeazzi fracture is a fracture of the distal third of the radius with dislocation of the distal radioulnar joint. It classically involves an isolated fracture of the junction of the distal third and middle third of the radius with associated subluxation or dislocation of the distal radio-ulnar joint; the injury disrupts the forearm axis joint.
Madelung's deformity is usually characterized by malformed wrists and wrist bones and is often associated with Léri-Weill dyschondrosteosis. It can be bilateral or just in the one wrist. It has only been recognized within the past hundred years. Named after Otto Wilhelm Madelung (1846-1926), a German surgeon, who described it in detail, it was noted by others. Guillaume Dupuytren mentioned it in 1834, Auguste Nélaton in 1847, and Joseph-François Malgaigne in 1855.
The stretch reflex is a muscle contraction in response to stretching within the muscle. It is a monosynaptic reflex which provides automatic regulation of skeletal muscle length.
The superficial branch of the radial nerve passes along the front of the radial side of the forearm to the commencement of its lower third. It is a sensory nerve.
The radial styloid process is a projection of bone on the lateral surface of the distal radius bone. It extends obliquely downward into a strong, conical projection. The tendon of the brachioradialis attaches at its base, and the radial collateral ligament of the wrist attaches at its apex. The lateral surface is marked by a flat groove for the tendons of the abductor pollicis longus and extensor pollicis brevis.
Primitive reflexes are reflex actions originating in the central nervous system that are exhibited by normal infants, but not neurologically intact adults, in response to particular stimuli. These reflexes are suppressed by the development of the frontal lobes as a child transitions normally into child development. These primitive reflexes are also called infantile, infant or newborn reflexes.
The posterior compartment of the forearm contains twelve muscles which are chiefly responsible for extension of the wrist and digits, and supination of the forearm. It is separated from the anterior compartment by the interosseous membrane between the radius and ulna.
The palmomental reflex (PMR) is a primitive reflex consisting of a twitch of the chin muscle elicited by stroking a specific part of the palm. It is present in infancy and disappears as the brain matures during childhood but may reappear due to processes that disrupt the normal cortical inhibitory pathways. Therefore, it is an example of a frontal release sign.
Watson's test is a diagnostic test for instability between the scaphoid and lunate bones of the wrist.
A Shoulder examination is a portion of a physical examination used to identify potential pathology involving the shoulder. It should be conducted with both shoulders exposed to assess for asymmetry and muscle wasting.
