The Shoulder / Elbow Region Flashcards
What are the movements available at the shoulder joint?
Flexion
Extension
Abduction
Adduction
Medial rotation
Lateral rotation
Elevation (via flexion or abduction)
Circumduction (combination of movements)
Which muscles are involved in shoulder flexion?
Deltoid (anterior fibers)
Pectoralis Major (clavicular head)
Range of Motion: 150-180°
Which muscles are involved in shoulder extension?
Deltoid (posterior fibers)
Teres Major
Latissimus Dorsi
Pectoralis Major (sternocostal head)
Range of Motion: 50-70°
Which muscles are involved in shoulder abduction and adduction?
Abduction (150-170°): Deltoid (middle fibers).
Adduction (30-40°): Latissimus Dorsi, Pectoralis Major, Teres Major, Coracobrachialis.
Which muscles are involved in medial and lateral rotation of the shoulder?
Medial Rotation (70-90°): Subscapularis, Pectoralis Major, Latissimus Dorsi, Deltoid (anterior fibers).
Lateral Rotation (70-90°): Infraspinatus, Teres Minor, Deltoid (posterior fibers).
Describe the pectoralis major muscle.
Attachments:
Proximal: Clavicular head (medial clavicle), Sternocostal head (sternum, 1-7 costal cartilages).
Distal: Lateral lip of intertubercular groove.
Nerve Supply: Medial and Lateral Pectoral Nerves (C5-8, T1).
Actions: Flexion, adduction, medial rotation of the shoulder.
Describe the latissimus dorsi muscle.
Attachments:
Proximal: Thoracolumbar fascia, spinous processes of T7-12, lumbar vertebrae, iliac crest, lower ribs.
Distal: Floor of intertubercular groove.
Nerve Supply: Thoracodorsal nerve (C6-8).
Actions: Extension, adduction, medial rotation of the shoulder.
Describe the deltoid muscle.
Attachments:
Proximal: Clavicle (anterior), acromion (middle), spine of scapula (posterior).
Distal: Deltoid tuberosity on humerus.
Nerve Supply: Axillary nerve (C5-6).
Actions: Flexion, abduction, extension, medial and lateral rotation of the shoulder.
What are the rotator cuff muscles, their nerve supply, and actions?
Supraspinatus:
Nerve: Suprascapular (C5-6).
Action: Abduction, stabilization of glenohumeral joint.
Infraspinatus:
Nerve: Suprascapular (C5-6).
Action: Lateral rotation, stabilization.
Teres Minor:
Nerve: Axillary (C5-6).
Action: Lateral rotation, stabilization.
Subscapularis:
Nerve: Upper and Lower Subscapular (C5-7).
Action: Medial rotation, stabilization.
What is the primary function of the rotator cuff?
Stabilizes the glenohumeral joint during movement.
Maintains the humeral head in the glenoid fossa.
Clinical relevance: Common site of tendinopathy or tears.
Describe the biceps brachii and its actions.
Proximal Attachment:
Long head: Supraglenoid tubercle.
Short head: Coracoid process.
Distal Attachment: Radial tuberosity and bicipital aponeurosis.
Nerve Supply: Musculocutaneous nerve (C5-6).
Actions: Shoulder flexion, elbow flexion, forearm supination.
What is the axilla, and what are its contents?
Borders:
Posterior: Subscapularis.
Anterior: Pectoralis Major.
Medial: Serratus Anterior/Ribs.
Contents:
Brachial plexus, Axillary artery and vein, Pectoralis Minor.
What are the bony components of the elbow joint?
Humerus
Ulna
Radius
What are the key bony landmarks of the humerus in the elbow region?
Medial and lateral epicondyles
Trochlea
Capitulum
Coronoid fossa
Radial fossa
Olecranon fossa
Describe the structure of the humero-ulnar joint.
Type: Synovial hinge joint.
Articular surfaces: Trochlea of humerus and trochlear notch of ulna.
Movement: Flexion and extension.
What is the superior radio-ulnar joint, and its features?
Type: Synovial pivot joint.
Articular surfaces: Head of radius and radial notch of ulna.
Ligaments: Annular ligament.
Movement: Pronation and supination.
What is the middle radio-ulnar joint, and its features?
Type: Fibrous syndesmosis.
Structure: Interosseous membrane with two layers running in opposite directions.
Function: Stabilizes radius and ulna, provides muscle attachment.
What are the movements at the elbow joint?
Flexion (140-150°): Biceps brachii, Brachialis, Brachioradialis.
Extension (0-5°): Triceps brachii, Anconeus.
Describe the brachialis muscle.
Origin: Anterior humerus.
Insertion: Ulna tuberosity.
Nerve supply: Musculocutaneous (C5-C6).
Nerve supply: Musculocutaneous (C5-C6).
What muscles are responsible for pronation of the forearm?
Pronator Teres
Pronator Quadratus
Brachioradialis
Describe the cubital fossa and its contents.
Borders:
Lateral: Brachioradialis.
Medial: Pronator Teres.
Superior: Imaginary line between epicondyles.
Contents:
Biceps brachii tendon.
Brachial artery.
Median nerve.
What is the clinical relevance of the olecranon process?
Common site of fractures and bursitis.
What are the key ligaments of the elbow joint?
Annular ligament: Stabilizes the superior radio-ulnar joint.
Quadrate ligament: Prevents over-pronation/supination.
Describe the triceps brachii muscle.
Origin:
Long head: Infraglenoid tubercle of scapula.
Medial/lateral heads: Posterior humerus.
Insertion: Olecranon.
Nerve supply: Radial nerve (C6-C8).
Action: Elbow extension, shoulder extension/adduction (long head).
What is the triangular fibrocartilaginous complex (TFCC)?
Found in the inferior radio-ulnar joint.
Provides stability during pronation and supination.
What are the movements at the radio-ulnar joint, and their ranges?
Pronation: 80-90°.
Supination: 90°.
Describe the biceps brachii muscle.
Origin:
Long head: Supraglenoid tubercle.
Short head: Coracoid process.
Insertion: Radial tuberosity and bicipital aponeurosis.
Nerve supply: Musculocutaneous nerve (C5-C6).
Actions: Shoulder and elbow flexion, supination.
What are the attachments and action of the supinator muscle?
Origin: Lateral epicondyle, radial collateral ligament, and supinator crest of ulna.
Insertion: Lateral radius above the oblique line.
Nerve supply: Posterior interosseous nerve (C6-C7).
Action: Supination.
