Movement Science Week 5 - Elbow Forearm Complex

Study Notes

Elbow and Forearm Complex

The elbow and forearm complex is comprised of three bones: humerus, radius, and ulna.
There are four joints that make up the complex: humeroradial joint, humeroulnar joint, proximal radio-ulnar joint, and distal radio-ulnar joint.
The trochlea and capitulum of the humerus are the two articulation points for the radius and ulna, respectively.
The medial and lateral epicondyles are palpable points on the humerus.
The olecranon process and trochlear notch are found on the ulna, but not the humerus.
The head of the ulna is convex and articulates with the radius distally.
The head of the radius is concave and articulates with the capitulum of the humerus.
Pronator quadratus attaches to the radius and facilitates pronation.
Supinator attaches to the radius and facilitates supination.
The carpal bones of the wrist rest within the radius and become fixed in a closed-chain position.
The elbow joint is a modified hinge joint, meaning there is slight axial rotation and side-to-side motion during flexion and extension.
The elbow joint is comprised of the humeroulnar and humeroradial joints.
Full extension of the elbow requires extensibility of the anterior structures (skin, biceps, anterior capsule, anterior fibers of the medial collateral ligament).
Full flexion requires extensibility of the posterior structures (posterior capsule, triceps).
The humeroulnar joint has a roll and slide in the same direction during flexion and extension.
The humeroradial joint also has a roll and slide in the same direction during flexion and extension.
Pronation and supination occur in the horizontal plane.
Supination is when the radius and ulna are aligned, and the hand is in a supinated position.
Pronation is when the radius rotates over the ulna.
The proximal radio-ulnar joint has a rotation without a slide because of the annular ligament.
The distal radio-ulnar joint has a traditional roll and slide during supination.
During closed-chain pronation, the ulna rotates around the fixed radius.
During closed-chain pronation, the humerus also rotates (external rotation) due to its connection to the ulna.
During closed-chain supination, the humerus rotates internally.
The humeroradial joint has a spin motion due to the concave favea of the radius against the convex capitulum of the humerus.
The humeroradial joint is prone to degeneration due to the compression torque from supinator and pronator muscles.

Description

Explore the anatomy of the elbow and forearm complex, which includes the humerus, radius, and ulna. This quiz covers the various joints, articulation points, and key muscles involved in forearm movements. Test your knowledge of this essential region of the human body.