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22 Cards in this Set

  • Front
  • Back
Biceps Brachii: Short Head
•Origin: Tip of Coracoid Process (of scapula)
•Insertion: Radial Tuberosity

Biceps Brachii: Long Head
•Origin: Supra-glenoid Tubercle (of scapula/biceps tendon)
•Insertion: Radial Tuberosity & Lacertus Fibrosis

Biceps Brachii: Function
•Latin – two headed muscle of the arm.
•Primary Function: Flexion of the elbow, weak flexion of the shoulder joint, and supination of the forearm.
•Flexes and abducts humerus if externally rotated.
•The long head exercise involves shoulder flexion.
•If weak: It can put additional stress on the other muscles that flex the elbow and shoulder.
•Activating the muscle can help give you greater strength and functionality in shoulder and elbow flexion.
Elbow Flexors/Extensors:
Biceps Brachii
Triceps Brachii: Medial Head
•Origin: Humerus (Posterior surface of distal half of the humerus).
•Insertion: Olecranon process of ulna
•Function: Extends the elbow. Emphasized in supination (palm toward bicep).

Triceps Brachii: Lateral Head
•Origin: Humerus (Posterior lateral surface of the proximal ½ of humerus).
•Insertion: Olecranon (Superior/Posterior surface)
•Function: Extends the elbow. Emphasized in pronation (Back of hand toward bicep).

Triceps Brachii: Long Head
•Origin: Infra-glenoid tubercle of Scapula
•Insertion: Olecranon (Posterior surface/deep fascia of forearm)
•Function: Extends & adducts the shoulder. Extends the elbow. Emphasized with palm neutral. With arm hanging: will pull humerus into acromion. Prevents it from being pulled out of socket. Opposes pull o flat and pec major from pulling humerus down and out of glenoid as they all adduct together.

Triceps Brachii: Function
•Latin - three headed muscle of the arm.
•Function: Extends the elbow and the shoulder (opposite function of the biceps).
•If weak, it can put stress on the other muscles that extend shoulder & elbow and contribute to tension in the shoulder & elbow flexors.
Elbow Flexors/Extensors:
Triceps Brachii
Brachialis: Attachments
•Origin: Humerus (Distal/Anterior Surface)
•Insertion: Coronoid Process of Ulna

Brachialis: Function
•Latin – muscle of the arm. Lies under the biceps on the front (anterior) of the arm.
•Function: Elbow Flexion. Emphasized in pronation.
•If weak, can put greater stress on the other flexors of the elbow.
•Activating the muscle can increase strength in elbow flexion
Elbow Flexors/Extensors:
Brachioradialis: Attachments
•Origin: Humerus (Lower/Lateral 1/3)
•Insertion: Radius (Lower/Lateral, superior to wrist/thumb)

Brachioradialis: Function
•Latin – muscle of the arm & forearm.
•Function: Elbow flexion. Emphasized in neutral.
•It also assists in pronation from a supinated position and supination from a pronated position.
•If weak, it can put stress on the other flexors of the elbow and pronators & supinators of the forearm.
•Activating the muscle can increase strength in these actions.
Elbow Flexors/Extensors:
Coracobrachialis: Attachments
•Origin: Coracoid Process (tip)
•Insertion: Humerus (Middle of the medial surface & border of the humerus).

Coracobrachialis: Function
•Attaches to the coracoid process and arm – hence the name. Located under the biceps brachii and is sometimes called the ‘armpit’ muscle.
•Flexes the shoulder: (GH-Joint)
•Adducts shoulder.
•External rotation.
•Small muscle that assists in flexion and horizontal adduction of the shoulder.
•If weak, can put greater stress on the other flexors and horizontal adductors of the shoulder.
Elbow Flexors/Extensors:
Anconeus: Attachments
•Origin: Lateral Epicondyle of Humerus (elbow)
•Insertion: Ulna (Upper/lateral ridge; Upper fourth of dorsal surface of ulna).

Anconeus: Function
•Greek – elbow. It’s a small muscle that crosses the elbow joint.
•Function: It is a weak elbow extensor and is emphasized in forearm supination.
•If the muscle is weak, it can put stress on the other muscles that extend the elbow and supinate the forearm.
•Activating the muscle can increase strength in elbow extension and forearm supination.
Elbow Flexors/Extensors:
Pectoralis Minor: Attachments
•Origin: Ribs 2-5 (Superior Aspect)
•Insertion: Coracoid Process (anterior surface)

Pectoralis Minor: Function
•Smaller chest muscle.
•Primary functions: Depression, downward rotation & anterior tilt of the scapula.
•Tilts the scapula anteriorly by tilting the corocoid process anteriorly and caudally, causing inferior angle to rotate medially.
•If tight: Interferes with upward rotation of scapula. More exaggerated with abdominal tightness, since ribcage cannot elevate as a compensation for pec minor tightness.
•Extension of humerus depends on fixation by the pec minor, levator and rhomboids.
•Encompasses brachioplexus: contributes to thoracic outlet syndrome.
•Tightness: noted by shoulders elevating 1 inch off the table.
•If weak, may feel tension in upward rotators and/or elevators of the scapulae.
Scapular Depressors:
Pectoralis Minor
Serratus Anterior: Upper Fibers
•Origin: Upper 4 Ribs (Outer/superior surface)
•Insertion: Scapula (Superior/Anterior/Medial Border)

Serratus Anterior: Lower Fibers
•Origin: Ribs 5-9 (Outer Superior Surface)
•Insertion: Inferior Angle of Scapula (anterior surface)

Serratus Anterior: Function
•Serrated shaped and on the lateral aspect of the trunk.
•Abducts and upwardly rotates the scapula. The Primary abductor of the scapula.
•Pulls scapula forward around the thoracic cage (protract or abduction).
•Timing of contraction is vital to avoid GH stress.
•Stabilizes scapula against the rib cage in elevation.
•Emphasis in pushing or punching motions.
•Force couple with upper/lower traps and levator to upwardly rotate scapula.
•Holds medial border firmly against thorax.
•Vital in overhead exercises.
•If weak: Pec minor, levator and rhomboids will still elevate but will lose abduction and rotation of the inferior angle. Inferior angle would move posterior and medial. Trapezius will be forced to overwork in attempt to upwardly rotate scapula. If positioning of scapula is not correct in both flexion and abduction, the scapulo-humeral muscles cannot maintain optimal length-tension relationships.
Scapular Abductors:
Serratus Anterior
Pectoralis Major: Clavicular Fibers
•Origin: Clavicle (Anterior/Inferior/Medial 1/3)
•Insertion: Greater Tubercle of Humerus (Lower lateral aspect of Bicipital groove)

Pectoralis Major: Sternal Fibers
•Origin: Sternum & cartilage of ribs 1-6 (Anterior surface)
•Insertion: Greater Tubercle of Humerus (crest)

Pectoralis Major: Costal Fibers
•Origin: Aponeurosis of External Oblique & Ribs 6-7 cartilage (Medial aspect)
•Insertion: Greater Tubercle of Humerus (Outer Bicipital ridge of humerus)

Pectoralis Major: Function
•Larger chest muscle.
•Function: Horizontally adducts and internally rotates the humerus.
•Clavicular Fibers: Assists in flexion and horizontal adduction. Assists in abduction and internal rotation in overhead motions.
•Sternal & Costal Fibers: Depress shoulder girdle.
•If tight will limit the range of lateral rotation in shoulder flexion.
•With latissimus dorsi: attach farther from axis of GH than scapulo-humeral rotators. Gives capability to dominate, creates excessive anterior glide of humeral head, and draws the shoulder downward and forward.
Humeral Adductors:
Pectoralis Major
Latissimus Dorsi: Attachments
•Origin: T6 – T12 SP’s. Ribs 9-12 Thoraco-lumbar fascia, Iliac Crest (posterior aspect).
•Insertion: Intertubercular Groove (inferior aspect of Bicipital groove)

Latissimus Dorsi: Function
•Latin for ‘widest of the back’. It’s the broadest muscle of the back.
•Primary function: Extension of the shoulder. It also adducts from an abducted position and internally rotates the shoulder joint.
•Depresses the shoulder girdle by pulling the humerus down.
•With pec major: attach farther from axis of GH than scapulo-humeral rotators. Gives capability to dominate. Creates excessive anterior glide of humeral head. Draws the shoulder downward and forward.
•With insertion fixed tilts pelvis anterior and extends the spine.
•Unilaterally can laterally flex the trunk.
•Lifts body toward fixed bar, as in pull-ups.
•Tightness limits shoulder flexion ROM: Weak abdominals can allow for greater perceived ROM in flexion.
•If weak: can put additional stress on the other muscles that extend and adduct the shoulder joint.
Humeral Adductors:
Latissimus Dorsi
Teres Major: Attachments
•Origin: Scapula Inferior Angle (Dorsal Surface) & Lower 1/3 of axillary border
•Insertion: Lesser Tubercle of Humerus (crest)

Teres Major: Function
•Latin – rounded, smooth. Referred to as the ‘little helper’ of the latissimus dorsi as it is a synergistic muscle.
•Primary functions are internal rotation, adduction and extension of the humerus/shoulder joint.
•Internally rotates and elevates: becomes highly active with loads overhead.
•If tight: scapula will laterally rotate immediately with abduction.
•Will limit humeral external rotation.
•If weak, it can put additional stress on the other internal rotators, adductors, and extensor muscles and create tension in the opposing – external rotators, abductors and flexors.
Humeral Adductors:
Teres Major
Supraspinatus: Attachments
•Origin: Supraspinatus Fossa (medial 2/3) & Spine of Scapula
•Insertion: Greater Tubercle of Humerus

Supraspinatus: Function
•Latin - on top/above the spine of the scapula.
•Initiates abduction of arm.
•One of the ‘rotator cuff’ muscles.
•Primary function: is assisting in abduction & stabilization of the shoulder joint.
•Depresses and stabilizes the head of humerus inward toward glenoid.
•Slight flexion and internal rotation of humerus.
•Vulnerable to injury when the shoulder is depressed.
•If weak, can put greater stress on the other abductor muscles.
Humeral Abductors:
Anterior Deltoid: Attachments
•Origin: Clavicle (Anterior/Lateral ½) & Acromion Process
•Insertion: Deltoid Tuberosity of Humerus (anterior/medial aspect)
•Function: Assists in shoulder flexion. Internally rotates in elevation past 90º. Assists in horizontal adduction. Two divisions: Clavicular & Scapular.

Middle Deltoid: Attachments
•Origin: Acromion Process (Superior/lateral aspect)
•Insertion: Deltoid Tuberosity (Lateral surface)
•Function: Primarily abduct the shoulder. Two divisions: Anterior & Posterior.

Posterior Deltoid: Attachments
•Origin: Spine of Scapula (inferior/medial ½)
•Insertion: Deltoid Tuberosity (Posterior Surface)
•Function: Extends and externally rotates humerus. Horizontally abducts humerus. Abduction with humerus internally rotated. Two Divisions: Medial & Lateral.

Deltoid: Function
•Greek for the letter ‘D’ – as it is so shaped.
•Function: Abducts the humerus.
•Very powerful muscle in abduction: Superiorly directed vector that pulls the humeral head towards the acromion. Vital that rotator cuff counter act this pull.
•Posterior Fibers: Most common weakness.
•Becomes shortened with supraspinatus in a depressed shoulder alignment.
•When short: GH joint becomes abducted. To compensate, the shoulders become depressed and downwardly rotated drawing the arms into the thorax.
•If depressed due to weak upper trapezius: the scapula must upwardly rotate too much. Deltoids will become too short to work effectively.
Humeral Abductors:
Subclavius: Attachments
•Origin: Manubrium & 1st Rib (Upper Border)
•Insertion: Clavicle & AC Joint junction(Inferior/Lateral)

Subclavius: Function
•‘Sub clavicle’: Small muscle that lies under the clavicle with its fibers running parallel to the clavicle.
•Synergistic muscle.
•Primary functions: Assisting in upward rotation of the scapulae and rotating the clavicle up and out of the way.
•Draws clavicle inferiorly and anteriorly.
•Elevates 1st rib and cartilage.
•Stabilizes SC-joint.
•If the muscle is weak, it can cause tension in the downward rotators.
Humeral Abductors:
Rhomboid Major
•Origin: T2 – T5 SP’s
•Insertion: Spine of Scapula (Vertebral border of scapula running from the spine to the inferior angle)

Rhomboid Minor
•Origin: Ligament nuchae (lower part) & C7 – T1 SP’s
•Insertion: Spine of Scapula (root)

Rhomboid Major: Function
•Shaped like a rhomboid.
•Function: Together the Rhomboids (Major & Minor) retract (or adduct – bring towards each other) and downwardly rotate the scapulae. They also assist in elevation and depression of the scapulae; bringing them into elevation when they are depressed and depression when they are elevated.
•With levator, can act as both synergist and antagonist to the trapezius. Resists the pull of the trapezius in upward rotation of the scapula (loaded shoulder shrug) creating downward rotation.
•Assists when humerus is extended or moves into extension.
•Must relax and lengthen in flexion and abduction.
•Rhomboid Major Weakness: Adduction strength will weaken due to inability to downwardly rotate scapula. Lose strength in extension of humerus due to limited capability for retraction. Increased tension on levator. Note: Lats and triceps lose ability if rhomboids are weak.
Scapular Adductors:
Upper Trapezius: Clavicular Fibers
•Origin: Superior nuchal line of occiput and nuchal ligament
•Insertion: Clavicle (Lateral 1/3)

Upper Trapezius: Scapular Fibers
•Origin: Occiput, nuchal ligament & C7 SP
•Insertion: Acromion (superior) & Spine of Scapula (Lateral 1/3)

Upper Trapezius: Function
•“Trapezius” – Shaped like a diamond. Adducts and upwardly rotates the scapula.
•Primary functions: elevation & upward rotation of the scapula; extension, lateral flexion & rotation of the head & neck.
•Elevates the scapula: resists the depression force of the lower trapezius. If weak, shoulder depression will result. Upper traps should allow shoulders to elevate when moving into shoulder flexion.
•Extends head and rotates chin to opposite side. If cervical spine is not stabilized, it will rotate head to opposite side during flexion of arm.
•Upward rotation of the scapula.
•Note: Upper Traps lose effectiveness without stability of scapula.
•Upper Trapezius Weakness: Levator and rhomboids become dominant creating downward rotation force on the scapula. Acromion end will drop and the shoulder will move forward. Crates inability to effectively elevate and abduct humerus. If Serratus takes over, excessive abduction of scapula. Increased tension if Serratus doesn’t initiate upward rotation.
•Shoulder shrugs: for proper upward rotation, should be performed overhead.
Scapular Elevators:
Upper Trapezius
Middle Trapezius: Attachments
•Origin: T1 – T5 SP’s
•Insertion: Spine of Scapula (Superior/Middle 1/3)

Middle Trapezius: Function
•“Trapezius”: Shaped like a diamond.
•Primary Function: Adduction and upward rotation of the scapula.
•Adduction, retracts scapula.
•Assists in flexion of the humerus near full range by helping rotate the scapula.
•Stabilizes scapula to produce shoulder flexion.
•Reinforces thoracic spine extension.
•If WEAK: Loses stability in shoulder flexion (middle) & Increase in thoracic kyphosis.
•If weak, it can put stress on the other adductors of the scapula.
Scapular Elevators:
Middle Trapezius
Lower Trapezius: Attachments
•Origin: T5 – T12 SP’s
•Insertion: Spine of Scapula (Superior/Medial at tubercle)

Lower Trapezius: Function
•“Trapezius”: Shaped like a diamond.
•Primary functions: Depression, adduction and upward rotation of the scapula.
•Adducts scapula, scapular depression, rotates glenoid fossa upward over 90º of abduction, reinforces thoracic spine extension.
•Pull downward on spine of scapula as arm elevates or abducts.
•Angle upward connecting to spine of scapula.
•Vital in overhead motions.
•If WEAK: Loses stability in shoulder flexion (middle) & Increase in thoracic kyphosis.
•If weak, it can cause tension in the downward rotators.
Scapular Elevators:
Lower Trapezius
Levator Scapulae: Attachments
•Origin: C1 – C4 TP’s (Lateral Aspect)
•Insertion: Superior Angle of Scapula & Spine of Scapula

Levator Scapulae: Function
•“Levator Scapulae”: Elevator of scapula.
•Unilateral Function: Elevation of the scapula, downward rotation of the scapula, lateral flexion of the head and neck, rotation of the head and neck to the same side.
•Bilateral Function: Extends the head and neck.
•Adduct & downwardly rotates scapula.
•Acts as a synergist to trapezius in adduction, but an antagonist in scapular rotation.
•Rotates head to the same side. Since the levator is stretched during flexion, an unstable cervical spine will result in rotation to the same side.
•Extension of the humerus with the rhomboids and triceps.
•Tightness represented by elevation of shoulder only at the medial border, not at the acromial end.
•Usually cause of a stiff neck.
•If weak, can put more stress on the upper trapezius and many of the neck muscles and scapular stabilizers.
Scapular Elevators:
Levator Scapulae
Infraspinatus: Attachments
•Origin: Infraspinatus Foss (Medial Aspect)
•Insertion: Greater Tubercle of Humerus (posterior aspect)

Infraspinatus: Function
•Latin – under/below the spine of the scapula.
•One of the ‘rotator cuff’ muscles.
•4 Divisions: Superior, Superior-Middle, Inferior-Middle, & Inferior.
•Primary Functions: External Rotation of humerus. Horizontal abduction of shoulder.
•Holds head of humerus in glenoid fossa (depressing the humeral head).
•If tight: May be a contributor to mid-scapular tension.
•Also, if tight, will contribute to excessive anterior glide of the humeral head contributing to impingement.
•Pain associated is usually in anterior shoulder.
•If weak, can put additional stress on the other external rotators and horizontal abductors of the shoulder joint.
Humeral Int/Ext Rotators:
Subscapularis: Attachments
•Origin: Subscapular Fossa (Anterior Surface)
•Insertion: Lesser Tubercle of Humerus

Subscapularis: Function
•Latin – under/below the scapula.
•One of the ‘rotator cuff’ muscles.
•Primary Functions: Internal Rotation of Humerus/shoulder & Horizontal adduction of the shoulder.
•4 Divisions: Superior, Superior-Middle, Inferior-Middle, & Inferior.
•Holds head of humerus in glenoid (depression).
•Depresses humerus in abduction against pull of deltoid.
•Pulls the head of the humerus posteriorly, offsetting the muscles which pull into anterior/superior glide.
•Provides anterior gleno-humeral stability (pulling head back prevents impingement).
•Many times, overpowered by the larger internal rotators (lat and pec major).
•Most activity in 0-90º of abduction.
•As deltoid no longer pulls: it relaxes also.
•If tight: Will limit function of supination which can impair function in the elbow, wrist, and hand.
•If weak, it can put additional stress on the other internal rotators and horizontal adductors of the shoulder joint.
Humeral Int/Ext Rotators:
Teres Minor: Attachments
•Origin: Axillary Border of Scapula (Posterior/Superior/Lateral 2/3)
•Insertion: Greater Tubercle of Humerus & Joint Capsule (Posterior/inferior aspect)

Teres Minor: Function
•Latin – rounded, smooth. Small muscle located between the teres major and the infraspinatus.
•One of the ‘rotator cuff’ muscles.
•Primary Function: External rotation of humerus/shoulder, horizontal abduction, extension of the humerus, & depression of the humeral head.
•Works with infraspinatus during elevation to stabilize humerus.
•If weak, can put additional stress on the other external rotators, abductors and extenders of the shoulder joint.
•Activating the muscle can help to stabilize the shoulder joint and increase strength through external rotation.
Humeral Int/Ext Rotators:
Teres Minor