Arm and Elbow Anatomy, Function & Pathology – PHTH 504

A comprehensive set of Question-and-Answer style flashcards covering bony landmarks, joints, ligaments, muscle O/I/A/N, cubital fossa, neurovascular structures, ROM, and common pathologies of the arm and elbow as discussed in the lecture notes.

What bony landmark lies halfway down the lateral humerus and serves as the deltoid insertion?

The deltoid tuberosity.

Name the two epicondyles of the distal humerus.

The medial epicondyle and the lateral epicondyle.

Which ridge on the humerus lies just proximal to the medial epicondyle?

The medial supracondylar ridge.

Which bone has a styloid process that can be palpated proximal to the thumb?

The radius.

Lister’s tubercle is also known as what?

The dorsal radial tubercle.

What large projection forms the point of the elbow on the ulna?

The olecranon process.

Which notch on the ulna articulates with the trochlea of the humerus?

The trochlear notch.

Name the three articulations that make up the elbow joint complex.

Humeroradial, humeroulnar, and proximal radioulnar joints.

Which elbow joint is classified as a pivot joint?

The proximal radioulnar joint.

What is the normal valgus (carrying) angle range in adult males?

Approximately 10–15 degrees.

What deformity is characterized by cubitus varus angulation at the elbow?

Gunstock deformity.

Which ligament encircles the head of the radius and keeps it against the ulna?

The annular ligament.

What structures provide primary static stability on the lateral side of the elbow joint?

The lateral collateral ligament complex.

What is the normal PROM range for elbow flexion?

0–150° with a soft (muscle-to-muscle) end-feel.

Which muscle is the prime supinator of the forearm when the elbow is flexed?

Biceps brachii.

List the proximal attachments of the deltoid muscle.

Lateral one-third of clavicle, acromion, and spine of scapula.

Which nerve innervates the deltoid?

Axillary nerve (C5, C6).

Where does the long head of biceps brachii originate?

Supraglenoid tubercle of the scapula.

Which nerve supplies both biceps brachii and coracobrachialis?

Musculocutaneous nerve.

What is the chief action of the brachialis muscle?

Flexion of the forearm in all positions.

Which muscles form the floor of the cubital fossa?

Brachialis and supinator.

Name the borders of the cubital fossa.

Superior: line between epicondyles; Lateral: brachioradialis; Medial: pronator teres; Roof: bicipital aponeurosis; Floor: brachialis & supinator.

List the main contents of the cubital fossa from lateral to medial.

Radial nerve (deep branch), biceps tendon, brachial artery (splitting into radial & ulnar), median nerve.

Which vein often used for venipuncture crosses the roof of the cubital fossa?

The median cubital vein (in the superficial fascia).

What nerve lies in the cubital tunnel posterior to the medial epicondyle?

The ulnar nerve.

Damage to which nerve in a mid-shaft humeral fracture commonly causes wrist drop?

The radial nerve.

What is Tommy John surgery designed to reconstruct?

The ulnar collateral ligament (UCL) of the elbow.

Which muscle abducts the ulna during pronation and helps extend the elbow?

Anconeus.

Give the insertion of triceps brachii.

Proximal end of olecranon of ulna and forearm fascia.

What is the chief action of triceps brachii?

Extension of the forearm; long head also stabilizes the humeral head during abduction.

Which artery is palpated in the cubital fossa to obtain a blood pressure reading?

The brachial artery.

Describe the mechanism commonly responsible for a distal biceps tendon rupture.

Traumatic overload, especially during eccentric contraction of the elbow flexors.

Why must a complete distal biceps rupture be repaired within two weeks?

After two weeks, scarring inhibits re-attachment to the radial tuberosity.

What clinical sign is associated with a distal biceps tendon rupture?

The “Popeye” sign (bulging proximal biceps muscle belly).

Which ligament keeps the long head of biceps in the intertubercular groove, tested by Yergason’s test?

The transverse humeral ligament.

What structure is palpated to test for olecranon bursitis?

The olecranon bursa overlying the posterior olecranon process.

Define epicondylitis.

Acute inflammation of the periosteum of an epicondyle and/or its tendinous attachments (tendinitis).

Which repetitive movement commonly causes lateral epicondylitis?

Repeated, forceful wrist extension (tennis elbow).

Which repetitive movement commonly causes medial epicondylitis?

Repeated, forceful wrist flexion (golfer’s or Little League elbow).

List three key conservative treatments for epicondylitis.

Activity modification/biomechanics, RICE, anti-inflammatory medication or injection, eccentric stretching, and strengthening.

What direction is most common in simple elbow dislocations?

Posterior or posterolateral displacement of ulna relative to distal humerus (~90%).

Loss of radial pulse after an elbow dislocation suggests injury to which vessel?

The brachial artery.

Name the two major superficial veins of the arm.

Cephalic vein and basilic vein.

Which muscle works with the biceps brachii to produce supination, especially when elbow is extended?

Supinator.

State the normal PROM range for forearm pronation and supination.

0–80° each with a firm (ligament/muscle) end-feel.

What is the major static stabilizer of valgus stress at the elbow in overhead athletes?

The anterior band of the ulnar collateral ligament (UCL).

Which anatomical feature on the distal humerus allows passage of the ulnar nerve?

The groove for the ulnar nerve (behind the medial epicondyle).

Describe the carrying angle differences between sexes.

Females generally have a carrying angle >15°, males 10–15°.

Name two muscles originating from the coracoid process.

Short head of biceps brachii and coracobrachialis.

Which muscle inserts on the tuberosity of the ulna?

Brachialis.

Which muscle’s proximal attachment is the infraglenoid tubercle?

The long head of triceps brachii.

The radial notch of the ulna articulates with which part of the radius?

The head of the radius (at the proximal radioulnar joint).

Which pathology involves inflammation of the synovial membrane overlying the olecranon?

Olecranon bursitis.

What precaution helps adolescents avoid UCL injury in pitching sports?

Limiting pitch counts, maintaining sub-maximal velocity (<85 mph), proper mechanics, strengthening forearm/shoulder, and taking 4 months off overhead throwing per year.

Which ligament rupture may allow subluxation of the long head of biceps during Yergason’s test?

Rupture of the transverse humeral ligament.