The Shoulder and Arm Flashcards
Supraspinatus
Proximal attachments: supraspinous fossa of the scapula. Distal attachments: greater tubercle of the humerus. Innervation: suprascapular nerve. Main functions: Abducts and stabilises arm at the glenohumeral joint.
Infraspinatus
Proximal attachments: Infraspinous fossa of the scapula. Distal attachments: Greater tubercle of the humerus. Innervation: suprascapular nerve. Main functions: laterally rotates, transversly abducts and stabilises arm at glenohumeral joint.
Teres minor
Proximal attachments: Posterior aspect of superior half of lateral border of scapula. Distal attachments: greater tubrcle of the humerus. Innervation: axillary nerve. Main functions: laterally rotates, transversely abducts and stabilises arm at glenohumeral joint.
Subscapularis
Proximal attachments: subscapular fossa of scapula. Distal attachments: lesser tubercle of the humerus. Innervation: upper and lower subscapular nerves. Main functions: Medially rotates and stabilises arm at glenohumeral joint.
Deltoid
- Anterior head - proximal attachments: clavicle (lateral third). Distal attachments: deltoid tuberosity of the humerus. Innervation: axillary nerve. Main functions: prime mover for flexion at the shoulder joint.
- Middle head - proximal attachments: scapula (lateral border of the acromion process). Distal attachments: deltoid tuberosity of the humerus. Innervation: axillary nerve. Main functions: [multipennate] abduction at the shoulder joint.
- Posterior head - proximal attachments: scapula (inferior lip of the spine of the scapula). Distal attachments: deltoid tuberosity of the humerus. Innervation: axillary nerve. Main functions: assist in extension.
Biceps Brachii
- Main functions: flexor at the elbow joint and supinator of the forearm. Weak flexors at the shoulder joint. Short head may adduct the arm.
- long head - Proximal attachments: scapula (supraglenoid tubercle), adjacent part of glenoid labrum. Distal attachments: posterior aspect of the radial tuberosity, deep fascia of the forearm (via bicipital aponeurosis). Innervation: Musculocutaneous nerve.
- short head - Proximal attachments: scapula (tip of coracoid process). Distal attachments: posterior aspect of the radial tuberosity, deep fascia of the forearm (via bicipital aponeurosis). Innervation: Musculocutaneous nerve.
Brachialis
Proximal attachments: distal half the the anterior surface of the humerus, intermuscular septa of the arm. Distal attachments: ulnar tuberosity and coronoid process, capsule of the elbow joint. Innervation: Musculocutaneous nerve. Main functions: flexor at the elbow joint [pure/true flexor].
Coracobrachialis
Proximal attachments: tip of the coracoid process on the scapula. Distal attachments: medial third of the anteromedial surface of the humerus. Innervation: Musculocuteneous nerve. Main functions: adductor and weak flexor at the shoulder joint
Triceps brachii
- Long head - proximal attachments: infraglenoid tubercle of the scapula, capsule of the shoulder joint. Distal attachments: olecranon process [ulna], capsule of the elbow joint. Innervation: radial nerve. Main functions: extension of the arm at the shoulder joint, [extensor at the elbow joint if the shoulder is flexed].
- Lateral head - proximal attachments: posterior surface above the radial groove of the humerus. Distal attachments: olecranon process [ulna], capsule of the elbow joint. Innervation: radial nerve. Main functions: extension of forearm at the elbow joint.
- Medial head - proximal attachments: posterior surface below the radial groove of the humerus. Distal attachments: olecranon process [ulna], capsule of the elbow joint. Innervation: radial nerve. Main functions: extension of forearm at the elbow joint.
what are the boundaries of the quadrangular space
superior=inferior margin of subscapularis
inferior=superior margin of teres major
lateral=surgical neck of humerus
medial=lateral margin of triceps long head
what are the contents of the quadrangular space
axillary nerve
posterior circumflex humeral artery
what are the boundaries of the triangular space
superior= inferior margin of subscapularis
inferior=superior margin of teres major
lateral=medial margin of triceps long head
what runs trough the triangular space
circumflex scapular artery and vein
what are the boundaries for the triangular interval
superior=inferior margin of teres major
medial=lateral margin of triceps long head
lateral=humerus shaft
what runs through the triangular interval
radial nerve leaves axilla to reach posterior arm
pec major insertions + innervation
bicipital groove TO clavicle/manubrium/sternum
medial and lateral pectoral nerves
pec minor insertions + innervation
coracoid process TO ribs 3-5
medial pectoral nerve
serratus anterior insertions + innervation
medial border of scapula TO ribs 1-9
long thoracic nerve
What are the insertions of the trapezoid ligament + is its function?
inserts between clavicle&coracoid process
function = LIMIT SCAPULAR ROTATION
What are the insertions of the conoid ligament + is its function?
inserts between clavicle&coracoid process
function = PREVENTS CALVICULAR UPWARD DISLOCATION
Most common position for humerus to dislocate + what nerve does this dislocation hit?
abducted + externally rotated + extended position
(holding soup behold you with straight up)
results in ANTERO-INFERIOR dislocation which HITS RADIAL NERVE**
what does costoclavicular ligament connect?
clavicle TO cartilage of rib 1
what does anterior sternoclavicular ligament connect?
spans across both clavicles connecting them to the manubrium
The final 15 degrees of a lateral raise is allowed by which joint?
sternoclavicular joint
