Shoulder Girdle

Question 1

Sternocleidomastoid:

O: medial or sternal head-cranial part of manubrium
O: lateral or clavicular head–medial 1/3 of clavicle

I: lateral surface of mastoid process, lateral half of superior nuchal line of occipital bone

A: bilateral: extension, flexion and lateral flexion
A: unilateral: contralateral rotation

N: Accessory Nerve & cervical 1, 2

Answer 1

Muscle Testing:
Sternocleidomastoid Anterior Neck Flexors:

Patient: supine with elbows bent, hands beside head, resting on table
Fixation: firm downward pressure on thorax
Test: anterolateral neck flexion
Pressure: against the temporal region of the head in an obliquely posterior direction

Question 2

Trapezius:
1. Upper fibres:

O: external occipital protuberance (EOP), medial 1/3 of superior nuchal line, ligamentum nuchae & spinous process of C7
I: lateral 1/3 of clavicle & acromion process of scapula

2. Middle fibres:
   O: spinous processes of T1-T5
   I: medial margin of the acromion
3. Lower fibres:
   O: spinous processes of T6 – T12
   I: Tubercle of the apex of the spine of the scapula

A: adduction, rotation, elevation & depression of the scapula. Unilateral: lateral flexion and contrarotation of the cervical spine. Bilateral: extension of the cervical spine.

N: CN XI – Accessory Nerve and ventral ramus from C2, C3, C4

Answer 2

Muscle Testing: Trapezius

• Upper Fibres:

Patient: sitting
Fixation: none
Test: elevate the acromial end of the clavicle and scapula, posterolateral extension of the neck, bringing the occiput towards the elevated shoulder with the face turned in the opposite direction.
Pressure: against the shoulder, in the direction of the depression and against the head.

• Middle Fibres:

Patient: prone, shoulder in 90 degrees of abduction and in lateral rotation
Fixation: one hand on the opposite scapular area to prevent trunk rotation
Test: adduction of the scapula with upward rotation and without elevation of the shoulder girdle
Pressure: against the forearm in a downward direction towards the table

• Lower Fibres:

Patient: prone
Fixation: examiner places one hand below the scapula on the opposite side
Test: adduction and depression of the scapula with lateral rotation of the inferior angle, line up the arm with the lower fibres
Pressure: against the forearm in a downward direction toward the table.

Question 3

Latissimus Dorsi:

O: spinous processes of T7-T12, last 3-4 ribs, into the thoracolumbar fascia (of lumbar & sacral regions), posterior 1/3 of external lip of the iliac crest and a slip from the inferior angle of the scapula.

I: intertubercular groove of the humerus

A: medially rotates, adducts, the extends the shoulder. Unilaterally: lateral flexion of the trunk, assists in tilting pelvis. Bilaterally: hyperextending the spine, flexing the spine
(may also help in breathing-respiration).

N: Thoracodorsal Nerve (C6, C7, C8)

Answer 3

Muscle Testing: Latissimus Dorsi:

Patient: prone
Fixation: examiner places one hand for counterpressure on the pelvis
Test: adduction of the arm with extension in the medially rotated position
Pressure: against the forearm in the direction of abduction and slight flexion of the arm.

Question 4

Rhomboid Major:

O: Spinous processes of T2-T5

I: fibrous attachment to medial border of the scapular between the spine and the inferior angle

A: adducts and elevates the scapula, some rotation to move the glenoid cavity downwards (caudally)

N: Dorsal scapular Nerve (C4, C5)

Answer 4

Muscle Testing: Rhomboids
Alternate Test:

Patient: prone
Fixation: one hand on the opposite scapular area to prevent trunk rotation, shoulder is in 90 degrees abduction, palm of hand is facing caudad
Test: adduction and elevation of the scapula with a downward rotation
Pressure: against the forearm in a downward direction toward the table.

Question 5

Rhomboid Minor:

O: ligamentum nuchae, spinous processes of C7, T1

I: Medial border at root of spine of scapula

A: adducts and elevates the scapula, some rotation to move the glenoid cavity downwards (caudally)

N: Dorsal scapular Nerve (C4, C5)

Answer 5

Muscle Testing: Teres Minor:

Patient: supine
Fixation: counter pressure is applied against the inner aspect of the distal end of the humerus
Test: lateral rotation of the humerus with the elbow held at a right angle
Pressure: using the forearm as a lever, pressure is applied in the direction of the medially rotating humerus

Question 6

Levator Scapulae:

O: transverse processes of C1 to C4

I: medial border of the scapula, between superior angle and root of the spine

A: elevates the scapula and assists in rotation to place the glenoid cavity facing caudally.Bilateral: extension cervical spine. Unilateral: lateral flexion, and ipsilateral rotation of the cervical spine.

N: Cervical C3, C4 and Dorsal scapular nerve (C4, C5)

Answer 6

Question 7

Pectoralis Major:

• Upper Fibres-clavicular portion:

O: anterior surface of the sternal ½ of the clavicle

I: crest of greater tubercle of humerus.

A: flex and medially rotate the shoulder joint, horizontally adduct the humerus to opposite shoulder

N: lateral pectoral (C5, C6, C7)
Lower Fibres-sternocostal portion

O: anterior surface of the sternum, cartilage of first 6-7 ribs, aponeurosis of the external obliques

I: crest of the greater tubercle of humerus.

A: depress the shoulder girdle (pulls down on the humerus), and obliquely adducts the humerus contralaterally

N: Lateral and medial pectoral (C6, C7, C8, T1)

Actions of the pecs as a whole: adducts and medially rotates the humerus.

Answer 7

Muscle Testing: Pectoralis Major

• Upper Fibres:
  Patient: supine
  Fixation: examiner holds opposite shoulder firmly on table, triceps maintain elbow in extension.
  Test: elbow extended, shoulder in 90 degrees of flexion and slight medial rotation. The humerus is horizontally adducted toward the sternal end of the clavicle.
  Pressure: against the forearm in the direction of horizontal abduction.
• Lower Fibres:
  Patient: supine
  Fixation: examiner holds opposite iliac crest to hold the pelvis firmly on the table.
  Test: starting with the elbow extended and the shoulder in flexion and slight medial rotation, adduction toward the opposite iliac crest.
  Pressure: against the forearm obliquely in a lateral and cranial direction.

Question 8

Pectoralis Minor:

O: superior margins, outer surfaces of the 3, 4, 5 ribs near the cartilages and nearby fascia

I: medial border superior surface of the coracoid process of the scapula

A: tilts the scapula anteriorly, aids in forced inspiration also

N: medial pectoral nerve with some fibres from lateral pectoral nerve (C6, C7, C8, T1)

Answer 8

Muscle Testing: Pectoralis Minor

Patient: supine
Fixation: none
Test: forward thrust of the shoulder with arm at side
Pressure: against the anterior aspect of the shoulder, downward toward the table.

Question 9

Subclavius:

O: first costal cartilage

I: inferior surface of the acromial end of the clavicle

A: pulls the shoulder forward and downward and stabilizes it

N: Nerve to the Subclavius (C5, C6)

Question 10

Serratus Anterior:

O: outer surfaces and superior borders of the upper 8-9 ribs

I: costal surface of the medial border of the scapula

A: abducts the scapula, rotates the inferior angle laterally and glenoid cavity cranially, holds the medial border of the scapula firmly against the rib cage, lower fibres may depress scapula, and upper fibres may elevate it. May also aid in forced inspiration.

N: Long Thoracic Nerve (C5, C6, C7, C8)

Answer 10

Muscle Testing: Serratus Anterior

Patient: supine
Fixation: none
Test: abduction of the scapula, projecting the arm anteriorly
Pressure: against the subjects fist

Question 11

Deltoid Muscles:

O: Anterior fibres: anterior border, superior surface and lateral 1/3 of the clavicle
O: Middle fibres: lateral margin and superior surface of the acromion
O: Posterior fibres: inferior lip of the posterior border of the spine of the scapula

I: deltoid tuberosity of the humerus

A: abduction of the shoulder joint, anterior fibres flex and medially rotate while the posterior fibres extend and laterally rotate the shoulder joint

N: Axillary Nerve (C5, C6)

Answer 11

Muscle Testing:

• Deltoid as a group:

Patient: sitting
Fixation: stable trunk
Test: shoulder abduction without rotation, may have flexed elbow
Pressure: against the dorsal surface of the distal end of the humerus

• Muscle Testing: Deltoid: Anterior:

Patient: sitting
Fixation: stabilize scapula
Test: shoulder abduction in slight flexion with humerus in slight lateral rotation.
Pressure: against the anteromedial surface of the arm in the direction of adduction and slight extension.

• Muscle Testing: Deltoid: Posterior

Patient: sitting
Fixation: stable trunk
Test: shoulder abduction in slight extension and humerus in slight medial rotation.
Pressure: against the posterolateral surface of the arm abover the elbow in the direction of adduction and slight flexion.

Question 12

Supraspinatus:

O: medial 2/3 of the supraspinous fossa of the scapula

I: superior facet of greater tubercle of the humerus

A: abducts and laterally rotates the shoulder joint, stabilizes the head of the humerus in the glenoid cavity

N: Suprascapular Nerve (C4, C5, C6)

Answer 12

Muscle Testing: Supraspinatus

• 1st option:

Patient: sitting or standing
Fixation: none
Test: initiation of abduction of the humerus
Pressure: against the forearm in the direction of adduction

• 2nd option:
  Patient: sitting or standing, neck extended and laterally flexed toward side being tested, face turned to the opposite side
  Fixation: none
  Test: with elbow bent at right angle, arm is placed in abduction to shoulder level in line with the supraspinatus.
  Pressure: against the forearm in the direction of slight anterior abduction and slight external rotation against pressure

Question 13

Infraspinatus:

O: medial 2/3 of the infraspinous fossa of the scapula

I: middle facet of the greater tubercle of the humerus and shoulder joint capsule

A: laterally rotates the shoulder joint, stabilizes the head of the humerus in the glenoid cavity

N: Suprascapular Nerve (C4, C5, C6)

Answer 13

Muscle Testing: Infraspinatus

Patient: prone
Fixation: arm rests on the table, examiner supports arm and stabilizes the humerus,
Test: lateral rotation of the humerus with the elbow held at a right angle
Pressure: using the forearm as a lever, pressure is applied in the direction of the medially rotating humerus

Question 14

Subscapularis:

O: subscapular fossa of the scapula

I: lesser tubercle of the humerus and shoulder joint capsule

A: medially rotates the shoulder joint and stabilizes the head of the humerus in the glenoid cavity

N: Upper and Lower Subscapular Nerves (C5, C6, C7)

Answer 14

Question 15

Teres Minor:

O: upper 2/3, dorsal surface of the lateral border of the scapula

I: inferior facet of the greater tubercle of the humerus and shoulder joint capsule

A: laterally rotates the shoulder joint and stabilizes the head of the humerus

N: Axillary Nerve (C5, C6)

Answer 15

Question 16

Teres Major:

O: dorsal surface of the inferior angle & lower 1/3 of the lateral border of the scapula

I: crest of the lesser tubercle of the humerus

A: medially rotates, adducts and extends the shoulder joint

N: Lower Subscapular Nerve (C5, C6, C7)

Answer 16

Muscle Testing: Teres Major

Patient: prone
Fixation: none
Test: extension and adduction of the humerus in the medially rotated position with the hand resting on the posterior iliac crest.
Pressure: against the arm, above the elbow in the direction of abduction and flexion