Back, Shoulder Girdle, & UE Muscle Cards

Sternocleidomastoid

1. proximal

2. distal

3. action

4. innervation

1. proximal

   1. sternal head: manubrium of sternum

   2. clavicular head: medical portion of the clavicle

2. distal

   1. mastoid process of temporal bone

   2. lateral portion of the superior nuchal line of occipital bone

3. action

   1. unilateral: Lateral flexion of neck to same side, rotation of head to opposite side

   2. Bilateral: Neck flexion and elevation of sternum during forced inspiration

4. innervation

   1. Spinal accessory nerve (Cranial Nerve XI)

   2. Sensory contributions from C2–C3

Latissimus Dorsi

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Spinous processes of T7–T12

  • Thoracolumbar fascia

  • Iliac crest

  • Inferior 3–4 ribs

• Distal:

  • Floor of the intertubercular groove of humerus

• Action:

  • Extension, adduction, and medial rotation of the humerus

  • Assists in movements such as climbing or swimming

• Innervation:

  • Thoracodorsal nerve (C6–C8)

Trapezius

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • External occipital protuberance

  • Medial superior nuchal line

  • Nuchal ligament

  • Spinous processes of C7–T12

• Distal:

  • Lateral third of clavicle

  • Acromion process

  • Spine of scapula

• Action:

  • Upper fibers: Elevate and upwardly rotate scapula, extend neck

  • Middle fibers: Retract scapula

  • Lower fibers: Depress and upwardly rotate scapula

• Innervation:

  • Spinal accessory nerve (Cranial Nerve XI)

  • Sensory from C3–C4

Levator Scapulae

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Transverse processes of C1–C4 vertebrae

• Distal:

  • Medial border of scapula, superior to the root of the spine

• Action:

  • Elevates scapula

  • Tilts glenoid cavity inferiorly by rotating scapula downward

  • Assists in lateral flexion of the neck

• Innervation:

  • Dorsal scapular nerve (C5)

  • Branches from C3 and C4

Rhomboid Major

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Spinous processes of T2–T5

• Distal:

  • Medial border of scapula from the spine to the inferior angle

• Action:

  • Retracts scapula

  • Elevates and downwardly rotates scapula

• Innervation:

  • Dorsal scapular nerve (C4–C5)

Rhomboid Minor

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Nuchal ligament

  • Spinous processes of C7 and T1

• Distal:

  • Medial border of scapula at the root of the spine

• Action:

  • Retracts scapula

  • Elevates and downwardly rotates scapula

• Innervation:

  • Dorsal scapular nerve (C4–C5)

Quadratus Lumborum

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Iliac crest

  • Iliolumbar ligament

• Distal:

  • Inferior border of the 12th rib

  • Transverse processes of L1–L4 vertebrae

• Action:

  • Unilateral: Lateral flexion of vertebral column to the same side

  • Bilateral: Extension of the lumbar spine

  • Assists in forced expiration by fixing the 12th rib

• Innervation:

  • Subcostal nerve (T12)

  • Branches from lumbar plexus (L1–L4)

Serratus Anterior

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • External surfaces of lateral parts of ribs 1–8 or 1–9

• Distal:

  • Anterior surface of the medial border of scapula

• Action:

  • Protracts scapula (pulls it forward around the rib cage)

  • Holds scapula firmly against thoracic wall

  • Assists in upward rotation of scapula

• Innervation:

  • Long thoracic nerve (C5–C7)

Supraspinatus

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Supraspinous fossa of scapula

• Distal:

  • Superior facet of the greater tubercle of humerus

• Action:

  • Initiates the first 15 degrees of arm abduction

  • Helps stabilize the glenohumeral joint

• Innervation:

  • Suprascapular nerve (C5–C6)

Infraspinatus

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Infraspinous fossa of scapula

• Distal:

  • Middle facet of the greater tubercle of humerus

• Action:

  • Lateral rotation of the humerus

  • Stabilizes the glenohumeral joint

• Innervation:

  • Suprascapular nerve (C5–C6)

Teres Minor

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Lateral border of scapula (upper two-thirds)

• Distal:

  • Inferior facet of the greater tubercle of humerus

• Action:

  • Lateral rotation of the humerus

  • Assists in adduction of the arm

  • Stabilizes the glenohumeral joint

• Innervation:

  • Axillary nerve (C5–C6)

Subscapularis

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Subscapular fossa of scapula

• Distal:

  • Lesser tubercle of humerus

• Action:

  • Medial rotation of the humerus

  • Assists in adduction of the arm

  • Stabilizes the glenohumeral joint

• Innervation:

  • Upper and lower subscapular nerves (C5–C7)

Teres Major

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Posterior surface of inferior angle of scapula

• Distal:

  • Medial lip of the intertubercular groove of humerus

• Action:

  • Medial rotation of the humerus

  • Adduction of the arm

  • Assists in extension of the arm

• Innervation:

  • Lower subscapular nerve (C5–C6)

Deltoid

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Lateral third of clavicle

  • Acromion process

  • Spine of scapula

• Distal:

  • Deltoid tuberosity of humerus

• Action:

  • Anterior fibers: Flexion and medial rotation of the arm

  • Middle fibers: Abduction of the arm (15° to 90°)

  • Posterior fibers: Extension and lateral rotation of the arm

• Innervation:

  • Axillary nerve (C5–C6)

Pectoralis Major

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Clavicular head: Anterior surface of medial half of clavicle

  • Sternocostal head: Anterior surface of sternum, costal cartilages of ribs 1–6, and aponeurosis of external oblique muscle

• Distal:

  • Lateral lip of the intertubercular groove of humerus

• Action:

  • Adduction and medial rotation of the humerus

  • Clavicular head: Flexion of the humerus

  • Sternocostal head: Extension of the humerus from a flexed position

• Innervation:

  • Lateral pectoral nerve (C5–C7)

  • Medial pectoral nerve (C8–T1)

Pectoralis Minor

1. proximal

2. distal

3. action

4. innervation

• Proximal:

  • Anterior surfaces of ribs 3–5 near their costal cartilages

• Distal:

  • Coracoid process of scapula (medial border and superior surface)

• Action:

  • Stabilizes scapula by drawing it anteriorly and inferiorly against thoracic wall

  • Assists in forced inspiration by elevating ribs

• Innervation:

  • Medial pectoral nerve (C8–T1)