Elbow and Forearm ComplexESAT 3600

Fundamentals of Athletic Training

Elbow joint

Distal end of humerus, proximal end of ulna and radius

2 joints Ulnohumeral (Trochlear) Radiohumeral

Elbow Skeletal Review (Humerus)

Medial epicondyle

Lateral epicondyle

Trochlea

Capitulum

Coronoid fossa

Olecranon fossa

Elbow Skeletal Review (RU)

Olecranon process

Coronoid process

Trochlear notch

Head of radius

Radial tuberosity

Elbow ArthrologyUlnohumeral joint

Resting position70° elbow flexion10° forearm

supination Closed pack position

Extension + supination

MovementsFlexion/Extension

Radiohumeral joint Resting position

Full extension + full supination

Closed packed position90° elbow flexion5° forearm supination

MovementsFlexion/ExtensionSupination/Pronation

Cubital Valgus Angleaka – Carrying Angle

Elbow Arthrokinematics

Elbow Joint StabilityStrong bony stability

Strong joint capsule

4 ligaments

Annular Prevents lateral

displacement of radial head

Lateral (radial) collateral Radial component Ulnar component

Elbow Joint Stability Continued

Ulnar collateral Anterior band Posterior band

Musculature’s Role in Elbow Joint Stability and Movement

Muscle stability provided by all muscles that cross joint Including wrist flexors and extensors

Flexion Biceps brachii Brachioradialis Brachialis Pronator teres

Extension Triceps brachii Anconeus

Radioulnar (RU) Joint3 articulations

Proximal Middle Distal

Weak bony arrangement

Strong ligamentous

RU ArthrologyProximal Radioulnar

joint Resting position

35° supination70° elbow flexion

Closed packed position

Distal radioulnar joint Resting position

10° supination Closed packed

position5° supination

RU Arthrokinematics

Ligamentous Stability of the Radioulnar Joint

ProximalAnnular ligament

Middle Interosseous

membrane

DistalA/P radioulnar

ligamentsfibrodisc

Musculature’s Role in Radioulnar Joint Stability and Movement

Muscles that cross radius and ulna provide stability

Supination Supinator Biceps brachii

Pronation Pronator teres Pronator quadratus

Mechanics of Biceps Pull3 joint muscle

Medial attachment to radius acts as wheel-axel configuration Produces supination

of pronated/neutral forearm

Powerful supinator at 90° of elbow flexion

Dual Role of the Pronator Quadratus

Muscles of Shoulder and Elbow

Biceps brachiiO: long head – supraglenoid

tubercle of the scapula; short head – apex of coracoid process of the scapula

I: radial tuberosity and bicipital aponeurosis

A: flexes and supinates the forearm at the elbow

RO-IA: both heads are active during flexion of the arm at the shoulder joint, with the long head being more active

Muscle of the ElbowBrachioradialis

O: proximal 2/3 of the lateral supracondylar ridge of the humerus and lateral intermuscular septum

I: lateral side of base of styloid process of the radius

A: flexion of the forearm at the elbow. Pronates and supinates to mid position

Muscle of the ElbowBrachialis

O: lower ½ of the anterior surface of the humerus

I: tuberosity and coronoid process of the ulna

A: flexes forearm at the elbow

Muscles of Shoulder and ElbowTriceps brachii

O: long head – infraglenoid tubercle of scapula; lateral head – superior ½ of posterior lateral surface of humerus; medial head – inferior 2/3 on the posterior surface of the humerus

I: supraposterior surface of the olecranon process of the ulna and deep fascia of the forearm

A: extends forearm at the elbow. Long head aids in adduction and extension of the arm at the shoulder

Muscle of the ElbowAnconeus

O: posterior surface of lateral epicondyle of humerus

I: lateral side of olecranon process and posterior surface of proximal portion of ulna

A: Extension and pronation of forearm at the elbow

Muscles of the Radioulnar Joint

Supinator O: lateral epicondyle

of humerus, radial collateral ligament of elbow, annular ligament of radius and the supinator crest of ulna

I: an oblique line on the lateral anterior surface of the upper 1/3 of radius

A: supinates the forearm

Muscles of the Radioulnar JointPronator Teres

O: humeral head – common flexor tendon from medial epicondyle of humerus and common flexor tendon; ulnar head – medial side of coronoid process of ulna

I: Middle 1/3 of lateral surface of radius

A: pronation of forearm and flexion of forearm at the elbow

Muscles of the Radioulnar Joint

Pronator QuadratusO: distal ¼ of the

anterior surface of the ulna

I: distal ¼ of the anterior surface of the radius

A: pronates the forearm