Chapter 2: Shoulder & Arm
Origin: Subclavius
1st rib & cartilage
Origin: Pectoralis Minor
3rd,4th, & 5th ribs
Which muscle is the cause of winged scapula?
A weak serratus anterior. Pectoralis major & minor can also play a role (they pull the shoulder girdle anteriorly).
Action: All Deltoid Fibers
Abduct shoulder
What are the 3 segments of the deltoid?
Anterior Middle Posterior
Insertion: Serratus Anterior
Anterior surface of medial boarder of scapula
When do you use your trapezius?
Biker extending neck over the handlebars Holding phone between shoulder and ear Carrying backpack Pulling shoulders back in military manner
What 3 segments is the pectoral major divided into?
Clavicular, sternal, costal
What muscle is the armpit muscle?
Coracobrachialis
Origin: Coracobrachialis
Coracoid process of scapula
Origin: Short Head Biceps Brachii
Corcacoid process of scapula
Insertion: Pectoralis Major
Crest of greater tubercle of hunerus
Insertion: Teres Major
Crest of lesser tubercle of humerus
Which muscles of this region are antagonistic to themself?
Deltoid Trapezius Pectoralis Major
Antagonist muscles for adduction of glenohumeral joint
Deltoid (all fibers) Supraspinatus
Synergistic muscles for abduction of glenohumeral joint
Deltoid (all fibers) Supraspinatus
Antagonistic muscles for lateral rotation of glenohumeral joint
Deltoid (anterior fibers) Latissimus Dorsi Teres Major Subscapularis Pectoralis Major (all fibers)
Synergistic muscles for medial rotation of glenohumeral joint
Deltoid (anterior fibers) Latissimus Dorsi Teres Major Subscapularis Pectoralis Major (all fibers)
Antagonistic muscles for extension of glenohumeral joint
Deltoid (anterior fibers) Pectoralis Major (upper fibers) Biceps Brachii Coracobrachialis
Synergistic muscles for flexion of glenohumeral joint
Deltoid (anterior fibers) Pectoralis Major (upper fibers) Biceps Brachii Coracobrachialis
Antagonist muscles for horizontal abduction of glenohumeral joint
Deltoid (anterior fibers) Pectoralis major (upper fibers)
Synergistic muscles for horizontal adduction of glenohumeral joint
Deltoid (anterior fibers) Pectoralis major (upper fibers)
Antagonist muscles for horizontal adduction of glenohumeral joint
Deltoid (posterior fibers)
Synergistic muscles for horizontal abduction of glenohumeral joint
Deltoid (posterior fibers)
Antagonistic muscles for medial rotation of glenohumeral joint
Deltoid (posterior fibers) Infraspinatus Teres Minor
Synergistic muscles for lateral rotation of glenohumeral joint
Deltoid (posterior fibers) Infraspinatus Teres Minor
Antagonistic muscles for flexion of glenohumeral joint
Deltoid (posterior fibers) Latissimus Dorsi Teres Major Pectoralis Major (lower fibers) Triceps Brachii (long head)
Synergistic muscles for extension of glenohumeral joint
Deltoid (posterior fibers) Latissimus Dorsi Teres Major Pectoralis Major (lower fibers) Triceps Brachii (long head)
Insertion: Deltoid
Deltoid Tberosity
Action: Posterior Deltoid Fibers
Extend shoulder Laterally Rotate shoulder Horizontally Abduct shoulder
Origin: Trapezius
External occipital protuberance, medial portion of superior nuchal line of the occiput, ligamentum nuchae & spinous processes of C-7 through T-12
Origin: Serratus Anterior
External surfaces of upper 8-9 ribs
True/ False: The deltoid is not an antagonist of itself?
False
True? False: The greater tubercle is located posterior and lateral to the acromion.
False. It is interior and lateral
True/ False: The deltoid tuberosity is found on the medial side of the mid-humeral shaft?
False. It is on the lateral side
True/ False: The infraglrnoid tuberacle is located at the superior aspect of the medial boarder of the scapula?
False. It is the superior aspect of the lateral boarder. This is where the long head of the triceps brachii attach.
True/False: The Teres Major and Minor rotate the arm in the same direction.
False. Major= Medially Minor= Laterally
Action: Anterior Deltoid Fibers
Flex shoulder Medial rotate shoulder Horizontaly Adduct shoulder
Insertion: Infrspinatus
Greater Tubercle of humerus
Insertion: Supraspinatus
Greater Tubercle of humerus
Insertion: Teres Minor
Greater Tubercle of humerus
What are the 3 landmarks on the posterior humerus (deep to the deltoid)?
Greater tubercle Lesser tubercle Intertubercular Groove
Origin: Teres Major
Inferior angle and lower 1/3 of lateral boarder of scapula
Original: Latissimus Dorsi
Inferior angle of scapula, spinous process of last 6 thoracic vertebrae, last 3-4 ribs, thoracolumbar aponeurosis & posterior illiac crest
Insertion: Subclavius
Inferior surface of middle 1/3 of clavicle
Origin: Long Head of Triceps Brachii
Infraglenoid tubercle of scapula
Origin: Infraspinatus
Infraspinous Fossa of scapula
Insertion: Latissimus Dorsi
Intertubercular groove of humerus
What does it mean when a muscle contracts (shortens)?
It is performing its action (synergistic action)
What does it mean when a muscle is lengthened?
It is performing its opposite action (antagonistic action)
Insertion: Trapezius
Lateral 1/3 of clavicle, acromion & spine of scapula
Origin: Deltoid
Lateral 1/3 of clavicle, acromion & spine of scapula
Which is the widest (broadest) muscle of the back?
Latissimus Dorsi
Antagonist muscles for abduction of glenohumeral joint
Latissimus Dorsi Teres Major Infraspinatus Teres Major Pectoralis Major (all fibers) Triceps Brachii (long head) Coracobrachialis
Synergistic muscles for adduction of glenohumeral joint
Latissimus Dorsi Teres Major Infraspinatus Teres Major Pectoralis Major (all fibers) Triceps Brachii (long head) Coracobrachialis
Which muscles are the handcuff muscles?
Latissimus Dorsi & Teres Major
Insertion: Subscapularis
Lesser Tubercle of humerus
Insertion: Rhomboid Major
Medial boarder of scapula between spine of the scapula & inferior angle
Insertion: Lavator Scapula
Medial boarder of scapula, between superior angle & superior portion of spine of scapula
Origin: Pectoralis Major
Medial half of clavicle, sternum & cartilage of 1st -6th ribs
Insertion: Pectoralis Minor
Medial surface of coracoid process of scapula
Insertion: Coracobrachialis
Medial surface of mid-humeral shaft
Insertion: Lateral Head of Triceps Brachii
Olecranon process of ulna
Insertion: Long Head of Triceps Brachii
Olecranon process of ulna
Insertion: Medial Head of Triceps Brachii
Olecranon process of ulna
Origin: Medial Head of Triceps Brachii
Posterior surface of distal 1/2 of humerus
Origin: Lateral Head of Triceps Brachii
Posterior surface of proximal 1/2 of humerus
Antagonistic muscles for upward rotaion of scapulothoracic joint joint
Rhomboid Major Rhomboid Minor Levator Scapula Pectoralis Minor
Synergistic muscles for downward rotation of scapulothoracic joint joint
Rhomboid Major Rhomboid Minor Levator Scapula Pectoralis Minor
Which muscles lie deep to the trapezius and superfical to the spinae muscles?
Rhomoid Major & Minor
Which muscle is deep to the subscapularis?
Serratus Anterior
Antagonistic muscles for adduction of scapulothoracic joint joint
Serratus Anterior (with the origin fixed) Pectoralis Minor
Synergistic muscles for abduction of scapulothoracic joint joint
Serratus Anterior (with the origin fixed) Pectoralis Minor
Origin: Rhomboid Major
Spinous Processes of T-2 through T-5
Origin: Rhomboid Minor
Spinous processes of C-7 & T-1
Origin: Subscapulais
Subscapular fossa of the scapula
Which is the only rotator cuff muscle that medial rotates?
Subscapularis
Which is the only rotator cuff that attaches to the lesser tubercle?
Subscapularis
Origin: Long Head Biceps Brachii
Supraglenoid tubercle of scapula
Which muscles make up the rotator cuff?
Suprapinatus Infrspinatus Teres Minor Subscapularis
Which 3 muscles attach at the greater tubercle?
Supraspinatus Infraspinatus Terres Minor
Which of the 3 rotator cuffs share the same attachment?
Supraspinatus, Infraspinatus, Teres Minor (all share the greater tubercle of the humerus
Origin: Supraspinatus
Supraspinous Fossa of scapula
Which muscle is "lats little helper"?
Teres Major
The articulating surface for the lateral end of the clavicle?
The Acromion (the A/C joint)
The tendon of which muscle lies in the intertubercular groove ?
The Biceps Brachii
What is the primary muscle in forearm supination?
The Biceps Brachii
What is the beak-like projection of the scapula?
The Coracoid Process
Which joint of the clavicle is wedge-shaped and contains a small, impalpable disk?
The S/C joint. The A/C joint is thin and smooth
Which muscle is only found in 5% of people and its function is unknown?
The Sternalis
What crosses under the pectoralis minor and can create a potential for neurovascular compression?
The brachial plexus, axillary artery & vein
Which bone is the last to develop in the human fetus?
The clavicle. Often not till the late teens/ early twenties) It is also the first bone to start ossifying (hardening)
Which muscle's origin is the attachment site of the trapezius?
The deltoids
The rotator cuff muscles stabilize which joint?
The glenohumeral joint (the shoulder)
When a muscle has multiple muscle fibers (upper, middle, lower), what is something you can know about the functions of the muscle?
The muscle is antagonistic to itself
How is the supraspinatus muscle different than the other rotator cuff muscles.
The only rotator cuff muscle that's not involved in rotation
The medial end of the clavicle articulates with what bone?
The sternum (The S/C joint)
Origin: Lavator Scapula
Transverse processes of C-1 through C-4
Antagonistic muscles for abduction of scapulothoracic joint joint
Trapezius (middle fibers) Rhomboid Major Rhoboid Minor
Synergistic muscles for adduction of scapulothoracic joint joint
Trapezius (middle fibers) Rhomboid Major Rhoboid Minor
Antagonistic muscles for downward rotaion of scapulothoracic joint joint
Trapezius (upper and lower fibers) Serratus Anterior (with the origin fixed)
Synergistic muscles for upward rotation of scapulothoracic joint joint
Trapezius (upper and lower fibers) Serratus Anterior (with the origin fixed)
Antagonistic muscles for depression of scapulothoracic joint joint
Trapezius (upper fibers, unilaterally) Rhomboid Major Rhomboid Minor Levator Scapula (unilaterally)
Synergistic muscles for elevation of scapulothoracic joint joint
Trapezius (upper fibers, unilaterally) Rhomboid Major Rhomboid Minor Levator Scapula (unilaterally)
Antagonistic muscles for elevation of scapulothoracic joint joint
Trapizius (lower fiber) Serratus anterior (with the origin fixed) Pectoralis Minor
Synergistic muscles for depression of scapulothoracic joint joint
Trapizius (lower fiber) Serratus anterior (with the origin fixed) Pectoralis Minor
The only muscle on the back of the arm?
Triceps Brachii
True/ False: The lesser tubercle is the attachment site for the subccapularis
True
True/False: The latissimus dorsi can affect the trunk and spine.
True
Insertion: Long Head Biceps Brachii
Tuberosity of radius & aponeurosis of biceps brachii
Insertion: Short Head Biceps Brachii
Tuberosity of radius & aponeurosis of biceps brachii
What are the 3 muscle groups of the trapezius?
Upper (descending)fibers Middle Lower (ascending)fibers
Origin: Teres Minor
Upper 2/3 of lateral boarder of scapula
Insertion: Rhomboid Minor
Upper portion of medial boarder of scapula, across from spine of the scapula
When do you use your deltoids?
Virtually any movement of the shoulder Slipping arm into jacket Raking, shoveling Rowing
What is the term for a postural condition in which the medial boarder of the scapula falls away from the rib cage & visibly protrudes posteriorly?
Winged Scapula
