Functional Anatomy of the Upper Body

Spine Muscles

Intrinsic Back Muscles

Deep

Multifundus

Actions: Stabilizes the vertebral body & extends the neck

Innervated by Dorsal Rami

Rotatores

Actions: Stabilizes the vertebral body, extends the vertebral body, and rotates it as well.

Innervated by the Dorsal Rami

Semispinalis

Actions: Extends the head and neck. Rotates them contralaterally

Innervated by the Dorsal Rami

Deep Minor

Infraspinales

Actions: Extension of the vertebral column and rotation

Innervated by the Dorsal Rami

intertransversarii

Actions: Stabilize the vertebral body, flexion

Innervated by the anterior and posterior rami

Levator Costarum

Actions: Elevating the ribs & lateral flexion of vertebral body

Innervated by the posterior rami of C8-T11 spinal n.

Intermediate Muscles

Erector Spinae

Iliocostalis, Longissimus, & Spinalis

Unilateral Actions: laterally flexes the vertebral column

Bilateral Actions: extension of the head , neck, back

Innervated by the Dorsal Rami

Superficial

Splenius Capitis & Cervicis

Unilateral Actions: Lateral flex the neck and rotate the head to one side to active muscle

Bilateral Actions : Extension of neck & head

Innervated by Dorsal Rami

Spine Movements

Flexion

Splenius muscles, iliocostalis, longissimus, spinalis, and rotatores

Elevation

Serratus Posterior Superior & Levator Costarum (ribs)

Trapezius, Levator Scapula , Rhomboids (Scapula)

Depression

Trapezius Rhomboids (scapula)

Serratus Posterior Inferior (ribs)

Extension

Rotatores (back) , Semispinalis & Interspinalis, Iliocostalis, longissimus, spinalis (head and neck), Splenius Capitis & Splenius Cervicis (head and neck) Latissimus Dorsi (arm)

Extrinsic Back Muscles

Superficial

Levator Scapulae

Innervated by Dorsal Scapular N. C4,C5 & Cervical C3,C4

Actions: Elevate the scapula

Rhomboid Major & Minor

Actions: Rotates scapula & glenoid cavity interiorly

Innervated by the Dorsal Scapular N. C4,C5

Latissimus Dorsi

Actions: Adduction, Downward rotation

Innervated by the Thoracodorsal N. C6,C7,C8

Trapezius

Innervated by the spinal accessory n. & cervical n. C3,C4

Actions: Ascending Trap. elevates the scapula Descending Trap. depresses the scapula. Middle Trap. does retraction

Intermediate

Serratus Posterior Superior

Actions: Expands ribs (inhalation)

Innervated by the intercostal N. 2-5

Serratus Posterior Inferior

Innervated by the Anterior Rami N. of T9-T12

Actions: Depresses the ribs for exhalation

Shoulder Complex

Muscles Acting on GH Abduction & Flexion

GH Muscles: Biceps (long head), Coracobrachialis, Anterior & middle Deltoid

ST Muscles: Trapezius & Serratus Anterior

Rotator Cuff Muscles: Supraspinatus, Infraspinatus, Teres Minor, Subscapularis

Muscles Acting on GH Adduction and Extension

Teres Major, Pectoralis Major, Head of Triceps , Posterior Deltoid, Latissimus Dorsi

Muscles Acting on GH Joint External Rotation

Posterior Deltoid, Infraspinatus, Teres Minor

Muscles Acting on GH Joint Internal Rotation

Latissimus Dorsi, Anterior Deltoid, Pectoralis Major, Subscapularis, Teres Major

Muscles Acting on Scapulothoracic Joint (ST)

Upwards Rotation

Upper and middle Trapezius, Serratus Anterior

Downward Rotation

Rhomboids & Pectoralis Minor

Retraction

Lower and middle Trapezius & Rhomboids

Protraction

Serratus Anterior

Elevation

Upper Traperzius, Rhomboids, Levator Scapulae

Depression

Lower Trapezius, Pectoralis Minor, Subclavius

Anterior Axio-Appendicular Muscles & Scapulohumeral Muscles

Supraspinatus

Actions: Initiates upward movement of arm and assists deltoid abduct the arm

Innervated by Suprascapular N. C4,C5,C6

Infraspinatus

Actions: Laterally rotates arm

Innervated by the Supraspinatus N C4,C5

Teres Major

Actions: helps Adduct arm and medially rotates arm

Innervated by the Lower Subscapular N. (C5,C6)

Pectoralis Major

Actions: Medially rotates arm & adduction

Innervated by the medial & lateral pectoral N. , Clavicular head (C5,C6), Sternocostal head (C7,C8,T1)

Subclavius

Actions: Depresses clavicle and anchors it

Innervated by the Subclavian N (C5,C6)

Serratus Anterior

Actions: Upwards Rotation, and protraction

Innervated by the long thoracic N. (C5,C6,C7)

Pectoralis Minor

Actions: Externally rotate arm, and Depression of arm

Innervated by the medial Pectoral N. C8,T1

Subscapularis

Actions: Internally rotates arm

Innervated by the upper and lower Subscapularis N. (C5,C6,C7)

Teres Minor

Actions: laterally Rotates arm

Innervated by the Axillary N. C5,C6

Deltoid

Acromial Actions: abducts arm

Spinal Actions: Extends and laterally rotates

Clavicular Actions: Flexes and medially rotates arm

Innervation Axillary N. C5,C5

Force Couples

GH Abduction

Supraspinatus & Middle Deltoid

ST Upward Rotation

Upper Trapezius, Lower Trapezius, & Serratus Anterior

ST Downwards Rotation

Rhomboids, Latissimus Dorsi, Pectoralis Minor

Brachial Plexus

Nerves

Radial N.

Innervates Triceps

C5,C6,C7,C8

Ulnar N.

C8,T1

Axillary N.

Innervates Deltoids & Teres Minor

C5,C6

Long Thoracic N.

Innervates Serratus Anterior

C5,C6,C7

Median N.

C5,C6,C7,C8,T1

Musculocutaneous N.

Innervates Biceps & Coracobrachialis

C5,C6,C7

Nerves Continued

Nerves Associated with Medial Cord

Medial Pectoral Nerve (C8,T1)

Innervates both Pectoralis Major & Minor

Medial Brachialis N. (C8,T1)

Medial Antebrachial N. (C8,T1)

Nerves Associated with the Lateral Cord

Dorsal Scapular Nerve (C4,C5)

Suprascapular N. (C4,C5,C6)

Subclavian N. (C4,C5)

Nerves Associated with the Posterior Cord

Upper Subscapular N. (C5,C6)

Lower Subscpular N.

Axillary N. (C5,C6)

Radial N. (C5,C6,C7,C8)

Innervates Triceps

Myotomes

Action: Shoulder Abduction, external rotation, elbow flexion

Action : Elbow flexion, wrist extension

Actions: Elbow extension, middle finger

Finger Abduction

Cords

Lateral Cord

Medial Cord

Posterior Cord

Dermatomes

"Guns Up"

Middle finger region

Pinky Region

Middle of forearm

Ligaments

AC Ligament

Acromioclavicular & Coracoclavicular ligament

Provides stability. Helps prevent the collarbone from moving too far back

GH Ligament

SGHL, MGHL, IGHL

Provides stability and helps prevent dislocating anteriorly

Bones

Scapula

Supraspinatus & Infraspinatus Fossa

corocoid

GH Fossa

Humerus

Greater & Lesser Tubercle

Vertebral Body

Clavicle

Trapezoid lie

conoid tubercle

sternal head