GHJ muscles Flashcards
List the flexors of the GHJ and the average ROM
Deltoid (anterior fibres)
Biceps Brachii
Pectoralis Major
ROM - 110 deg + 70 deg through elevation of shoulder girdle
List the extensors of the GHJ and the average ROM
Deltoid (Posterior fibres)
Triceps
Latissimus dorsi
Teres major
ROM - 70 deg + 20 deg through shoulder elevation
List the abductors of the GHJ and the average ROM
Supraspinatus
Deltoid
ROM - supraspinatus does first 20-30 deg, then deltoid becomes prime mover. ROM of 110-120 (Humerus laterally rotates to help with this)
List the adductors of the GHJ and the average ROM
Pectoralis major
Latissimus dorsi
Teres major
ROM -
List the medial rotators of the GHJ and the average ROM
Pectoralis Major
Deltoid (anterior fibres)
Subscapularis
Latissimus dorsi
ROM - 90 deg
List the lateral rotators of the GHJ and the average ROM
Teres minor
Infraspinatus
Deltoid (posterior fibres)
ROM - 80 deg
Describe the morphology, attachments, actions, function and nerve supply of the biceps brachii
Morphology - fusiform muscle on anterior upper arm, has 2 heads. Proximal part covered by deltoid
Origin -
SH - coracoid process
LH - supraglenoid tubercle of the scapula and labrum, passes through intertubercular groove of humerus.
Insertion - Both join together, twist 90 deg and insert into the radial tuberosity
Action - Flexes elbow, flexes shoulder, supinates forearm
Function - screw driver/ corkscrew
Nerve supply - musculocutaneous nerve from the lateral cord of the brachial plexus C5,6.
Describe the morphology, attachments, actions, function and nerve supply of the deltoid
Morphology - multipennate, thick, coarse triangular muscle
Origin -
Anterior head - anterior border of lateral 1/3 of clavicle
Middle head - lateral border of acromion process
Posterior head - lower lip of spine of scapula
Insertion - deltoid tuberosity
Action - Flexion (ant) , abduction (middle) , extension (post), medial (ant) and lateral rotation (post), adduction - work to counteract the lats dorsi and pec major medial rotation)
Function - star jumps
Nerve supply - axillary nerve from the posterior cord of the brachial plexus (C5,6)
Describe the morphology, attachments, actions, function and nerve supply of the pectoralis major
Morphology - thick, course triangular shaped muscle that is superficial.
Origin -
Clavicular head - medial third of the clavicle
Sternocostal head - manubrium process, outer surfaces of the top 6 costal cartilages and ribs
Insertion - clavicular head inserts onto the lower part of the lateral lip of the intertubercular groove, forming the anterior lamina
The sternocostal head insters into the upper part of the lateral lip of the intertubercular groove, forming the posterior lamina.
Action - Medial rotation, flexion and adduction of the GHJ
Function - climbing muscle if arms above head + lats. Punching movements, press ups.
Nerve supply - Medial and lateral pectoral nerves (Clavicular part = C5,6, Sternocostal part C7,8)
Describe the morphology, attachments, actions, function and nerve supply of the triceps
Morphology - 3 heads (medial, lateral, long) on posterior arm
Origin -
Long head - infraglenoid tubercle of the scapula and glenoid labrum
Medial head - below and medial to the spiral groove on the posterior surface of the humerus + intermuscular septum.
Lateral head - above and lateral to the spiral groove on the posterior surface of the humerus
Insertion - all 3 become a tendon that insert into the olecranon process of the ulna and the deep fascia of the forearm
Action - extension of GHJ and elbow
Function - lowering yourself into a chair, wheel chair pushing, push ups, pushing and punching.
Nerve supply - Radial nerve from posterior cord of brachial plexus C5,6,7,8
Describe the morphology, attachments, actions, function and nerve supply of the latissimus dorsi
Morphology - a large, flat, triangular muscle.
Origin - Thoracodorsal fascia, posterior iliac crest, limbar and sacral vertebrae.
Insertion - intertubercular groove of the humerus (fibres twist 180 degrees here) and crosses the inferior angle of the scapula
Action - adduction, medial rotation, extension of GHJ when elbow flexed, retracts shoulder girdle
Function - downstroke in swimming, forceful expiration
Nerve supply - thoracodorsal nerve from the posterior cord of the brachial plexus.
Describe the morphology, attachments, actions, function and nerve supply of the teres major
Morphology -
Origin - inferior angle and lateral border of the scapula
Insertion - medial lip of intertubercular groove of humerus.
Action - adduction, medial rotation and extension of GHJ
Function -
Nerve supply - lower subscapular nerve C5,6,7
Describe the morphology, attachments, actions, function and nerve supply of the supraspinatus
Morphology -
Origin - medial 2/3 of the supraspinous fossa of the scapula
Insertion - greater tubercle of the humeral head
Action - initial 20-30 degrees of abduction.
Function - keeps the head of the humerus against the glenoid fossa.
Nerve supply - suprascapular nerve.
Describe the morphology, attachments, actions, function and nerve supply of the infraspinatus
Morphology - thick triangular muscle
Origin - medial 2/3 of the infraspinous fossa of the scapula
Insertion - greater tubercle of the humeral head.
Action - lateral rotator of the GHJ
Function - stabilise humeral head when laterally
rotating in abduction to stop head hitting coracoacromial arch. Pushes humeral head in glenoid fossa when carrying heavy objects.
Nerve supply - suprascapular nerve (C5,6)
Describe the morphology, attachments, actions, function and nerve supply of the teres minor
Morphology - thin muscle
Origin - upper 2/3 of the lateral border of the scapula
Insertion - greater tubercle of humeral head and capsule
Action - lateral rotator of the GHJ
Function - keeps humeral head close to glenoid fossa.
Nerve supply - axillary nerve
