Arm, Elbow, and Cubital Region
Supination occurs _______
As the radial head spins on the capitulum
Epicondyles
Bumpy areas on the distal end of the humerus that are the primary sites of muscle attachment; medial and lateral
The olecranon process is in close approximation to the distal humerus in the olecranon fossa in what position of the elbow?
Extension
The elbow is most stable in which position?
Extension (the olecranon is locked right into the distal humerus, so there is lots of bony stability)
The olecranon process pulls away from the distal humerus in what position of the elbow?
Flexion
Which three elbow joints share a joint cavity?
Humeroulnar, humeroradial, and proximal radioulnar
Four joints in the elbow region
Humeroulnar, humeroradial, proximal radioulnar, distal radioulnar
Trochlea
Lateral region of the condyle that articulates with the ulna
Annular Ligament
Ligament that encircles the head of the radius and holds it against the ulna; provides stability at the humeroradial joint and protects against distal dislocation of the radius
Medial (Ulnar) Collateral Ligament
Ligament that runs from the epicondyle of the humerus to the coronoid process and olecranon process; protects against valves (lateral) deviation of the forearm
Lateral (Radial) Collateral Ligament
Ligament that runs from the lateral epicondyle to the annular ligament of the radius; protects against virus (medial) deviation of the forearm
Capitulum
Medial region of the condyle that articulates with the radius
Humeroradial Joint
Modified hinge joint that is responsible for flexion/extension and some rotation of the elbow
Supination/pronation occurs:
Primarily at the proximal and distal radioulnar joints; there is associated rotation at the humeroradial joint
Three fossae in the distal humerus
Radial and coronoid (anterior), olecranon (posterior)
Boundaries of the cubital fossa:
Superior: an imaginary line connecting the medial and lateral epicondyles Medial: pronator teres Lateral: brachioradialis
Cubital Fossa
The triangular hollow area on the anterior aspect of the elbow
Why does the radius spin and the ulna does not?
The ulna is locked into the olecranon fossa while the radius has a flat head that can spin
Condyle
articulating surface with two regions: capitulum and trochlea; at the distal end of the humerus; smooth and covered with cartilage
Proximal Radioulnar Joint
Uniaxial joint in the elbow region responsible for supination/pronation of the hand (turning palm up/turning palm down)
Distal Radioulnar Joint
Uniaxial joint responsible for supination/pronation of the hand
Humeroulnar Joint
Uniaxial joint that is responsible for flexion/extension of the elbow