Elbow Joint Anatomy and Function Quiz

The elbow complex comprises 2 joints within a single joint capsule.

The humeroulnar joint is primarily responsible for the flexion and extension motions of the elbow.

The radius and ulna are linked with the elbow but do not facilitate rotation.

The elbow joint is classified as a modified or loose hinge joint with 2 degrees of freedom.

The distal radioulnar joint functions independently from the proximal radioulnar joint.

The lateral epicondyle is located medially at the end of the shaft of the humerus.

The muscles that cross the elbow complex also impact the functionality of the shoulder.

The elbow complex is essential for performing activities involving tools or implements due to its stabilizing function.

Supination and pronation movements occur at the humeroulnar joint.

The medial lip projects distally at an angle of 4-8° relative to the lateral lip.

The trochlear groove is located posteriorly on the humerus.

Muscles insert on the medial and lateral epicondyles of the humerus.

The olecranon fossa is situated distally to the trochlea on the posterior aspect of the humerus.

The coronoid process of the ulna projects sharply from the posterior proximal ulna.

The brachialis and brachioradialis muscles originate from the anterior aspect of the humerus.

The ulna has a concave trochlear notch that is a large jawlike process.

The radial notch of the ulna is located superior to the trochlear notch.

Muscles originating from the medial epicondyle include the supinator.

The deep membrane separates the olecranon fossa from the coronoid fossa.

The radial nerve innervates the pronator quadratus muscle.

The ulnar nerve encompasses the innervation of the dorsal interossei muscles.

The flexor digitorum profundus is innervated by the radial nerve.

The median nerve provides innervation to the flexor pollicis brevis muscle.

The biceps brachii muscle is innervated by the ulnar nerve.

The extensor digiti minimi muscle is innervated by the median nerve.

The normal cubitus valgus angle of the elbow is approximately 30° from the longitudinal axis of the humerus.

Cubitus varus is defined as a forearm deviation of 5° or more medially.

In healthy conditions, articular congruency plays a minor role in stabilizing the humero-ulnar joint during extension.

Excessive cubitus valgus represents an angle deviation of 15° laterally from the longitudinal axis of the humerus.

During active flexion, the anterior muscles of the arm and forearm primarily limit the movement before passive structures do.

The posterior dislocation of the elbow occurs only if the olecranon is fractured.

When the elbow is fully extended, the impact of the olecranon process in the olecranon fossa contributes to joint stability.

In passive elbow flexion, the capsular ligament has the most significant impact on stability.

The trochlear groove is responsible for the direction of the forearm during elbow extension.

The longitudinal axis of the humerus has no relationship with the carrying angle of the elbow.

The brachialis muscle is the least effective elbow flexor due to its small cross-sectional area.

The primary action of the biceps brachii is performed with the forearm in a pronated position.

The triceps brachii operates efficiently at an angle between 20°-30° due to optimal force application from its tangential component.

The anconeus muscle is primarily responsible for flexing the elbow joint.

Optimal muscle stretch enhances the power of contraction from both the biceps and triceps.

The brachioradialis performs full flexion regardless of the forearm's position.

Only the biceps brachii acts as a polyarticular muscle that produces force across multiple joints.

The primary elbow extensors include the brachialis and brachioradialis.

The contraction of the elbow flexor and extensor muscles creates instability in the joint when near 90°.

The secondary assisting synergists in elbow flexion include the pronator teres and ECRL.