Functional anatomy of the forearm and elbow.ppt

Functional anatomy of the elbow and forearm The elbow includes: 3 bones (humerus, radius, and ulna) 2 joints (humeroulnar and humeroradial) Allows for elbow flexion and extension The forearm includes: 2 bones (radius and ulna) 2 joints (proximal radioulnar joint and distal radio...

Functional anatomy of the elbow and forearm The elbow includes: 3 bones (humerus, radius, and ulna) 2 joints (humeroulnar and humeroradial) Allows for elbow flexion and extension The forearm includes: 2 bones (radius and ulna) 2 joints (proximal radioulnar joint and distal radioulnar joint) oAllows for forearm pronation and supination The interaction among the 4 joints enables the hand to be placed in a nearly infinite number of positions, greatly enhancing the functional potential of the entire UE  Humeroulnar Joint Provides most of the structural stability to the elbow through the jaw-like trochlear notch of the ulna interlocking with the spool-shaped trochlea of the humerus Humeroradial Joint Formed by the ball-shaped capitulum of the humerus with the bowl-shaped fovea of the radius This permits continuous contact between the radial head and the capitulum during pronation and supination, as the radius spins about its own axis  Proximal radioulnar joint Articulation of the head of the radius and the radial notch of the Ulna Distal radioulnar joint Distal end of the radius rotates around the distal end of the ulna Supination and Pronation occur at both joints and in the FOREARM Distal Humerus (Anterior): Trochlea Capitulum Medial Epicondyle Lateral Epicondyle Ulna nerve sulcus Radial Fossa Distal Humerus (Posterior): Trochlea Medial Epicondyle Lateral Epicondyle Lateral Supracondylar Ridge Olecranon Fossa Proximal Ulna (Lateral): Olecranon Process Trochlear Notch Coronoid Process Ulnar Tuberosity Proximal Ulna (Anterior): Olecranon Process Trochlear Notch Coronoid Process Radial Notch Radius: Head Radial tuberosity Neck Radial tuberosity Proximal Structures of the Elbow & Forearm  Distal Structures of the Forearm Ulna Head Styloid process Radius Styloid process The proximal radius rotates around the ulna which is stationary The distal radius is larger and broader than the distal ulna  Supporting Structures of the Elbow Articular Capsule - Thin connective tissue encasing 3 articulations Medial (Ulna) Collateral Ligament: Crosses the elbow medially from the medial epicondyle to the coronoid and olecranon processes Helps provide stability in resisting cubital valgus forces Lateral (Radial) Collateral Ligament: Crosses the elbow laterally from the lateral epicondyle to the annular ligament Helps provide stability in resisting cubital varus forces Annular Ligament Band of fibres that circle the radius Maintains contact between R & H The Muscles of the Elbow & Forearm: Biceps Brachialis Brachioradialis Triceps Anconeus Supinator Pronator teres Pronator quadratus  Muscles of the Elbow Brachioradialis Origin = Lateral epicondyle of the humerus Insertion = Styloid process of the radius. Action = Elbow joint flexion.  Muscles of the Elbow Brachialis Origin = Lower half of the humerus, anterior surface. Insertion = Coronoid process of the ulna, anterior surface. Action = Elbow joint flexion.  Muscles of the Elbow Supinator Origin = Lateral epicondyle of the humerus; adjacent portion of the ulna; as well as the annular and radial collateral ligaments. Insertion = Upper third of the radius, lateral surface. Action = Supination of the  Muscles of the Elbow Biceps Brachii Origin = Two proximal insertions Long head - Upper rim of glenoid fossa Short head - Coracoid process of scapula Insertion = Radial tuberosity. Action = Elbow joint flexion and  Muscles of the Elbow Triceps Brachii Origin = (Three Attachment Points) Long head - Infragleniod tuberosity of the scapula. Lateral head - Posterior surface of the humerus, lower half. Medial head - Posterior surface of the humerus, lower two-thirds. Insertion = Olecranon process of the  Muscles of the Elbow Anconeus Origin = Lateral epicondyle of the humerus, posterior surface. Insertion = Lateral portion of the olecranon; upper ulna, posterior surface. Action =  Muscles of the ElbowTeres Pronator Origin = Humeral head - Medial epicondyle of the humerus. Ulnar head - Coronoid process of the ulna. Insertion = Midpoint of the lateral surface of the radius. Action = Pronation of radioulnar joint, elbow joint flexion.  Muscles of the Elbow Pronator Quadratus Origin = Palmar surface of the ulna, lower fourth. Insertion = Palmar surface of the radius, lower fourth. Action = Pronation of the radioulnar joint.  Practical – in groups Demonstrate 2 strengthening exercises (using exercise machines) for the elbow muscles (name the muscles) responsible for the following actions: Flexion & Extension Pronation and supination  Practical – in groups Demonstrate 2 strengthening exercises (using own body weight, tubing, dumbells) for each shoulder muscles (name the muscles) responsible for the following actions: Flexion & Extension Pronation and supination Demonstrate 2 flexibility exercises for the elbow