Upper Extremity Upper Extremity MusculatureMusculature

Shoulder ComplexShoulder Complex ScapulaScapula ClacivleClacivle SternumSternum HumerusHumerus Rib CageRib Cage Sternoclavicular JointSternoclavicular Joint Acromioclavicular JointAcromioclavicular Joint Glenohumeral JointGlenohumeral Joint Scapulothoracic Joint / ArticulationScapulothoracic Joint / Articulation

Shoulder GirdleShoulder Girdle

Motions available at the shoulder girdle are Motions available at the shoulder girdle are upward rotation, protraction, downward upward rotation, protraction, downward rotation, retraction, and scapular tilt (when rotation, retraction, and scapular tilt (when the shoulder enters hyperextension)the shoulder enters hyperextension)

Scapulohumeral rhythm: The first 30 Scapulohumeral rhythm: The first 30 degrees of shoulder joint motion is pure GH degrees of shoulder joint motion is pure GH motion. After the initial 30 degrees, for motion. After the initial 30 degrees, for every 2 degrees of shoulder flexion or every 2 degrees of shoulder flexion or abduction, the scapula must upwardly abduction, the scapula must upwardly rotate 1 degree. This results in a 2:1 ratio.rotate 1 degree. This results in a 2:1 ratio.

Scapulothoracic JointScapulothoracic Joint

Articulation of scapula with thorax Articulation of scapula with thorax Not a true jointNot a true joint Muscles associated with ST Joint Muscles associated with ST Joint

(shoulder girdle)(shoulder girdle) TrapeziusTrapezius Rhomboid MajorRhomboid Major Rhomboid MinorRhomboid Minor Levator ScapulaeLevator Scapulae Serratus AnteriorSerratus Anterior Pectoralis MinorPectoralis Minor

TrapeziusTrapezius

Upper TrapeziusUpper Trapezius

Origin Origin Occipital Bone, nuchal ligament Occipital Bone, nuchal ligament on cervical spinous processeson cervical spinous processes

Insertion Insertion Lateral third of clavicle, Lateral third of clavicle, acromion processacromion process

Action Action Scapular elevation and upward Scapular elevation and upward rotationrotation

Innervation Innervation Spinal accessory (cranial Spinal accessory (cranial nerve XI), C3-C4 sensory componentnerve XI), C3-C4 sensory component

Middle TrapeziusMiddle Trapezius

Origin Spinous processes of C7 Origin Spinous processes of C7 through T3through T3

Insertion Scapular spineInsertion Scapular spine Action Scapular retractionAction Scapular retraction Innervation Spinal accessory Innervation Spinal accessory

( cranial nerve XI), C3 and C4 ( cranial nerve XI), C3 and C4 sensory componentsensory component

Lower TrapeziusLower Trapezius

Origin Spinous processes of middle Origin Spinous processes of middle and lower thoracic vertebraeand lower thoracic vertebrae

Insertion Base of the scapular spineInsertion Base of the scapular spine Action Scapular depression and Action Scapular depression and

upward rotationupward rotation Innervation Spinal accessory Innervation Spinal accessory

( cranial nerve XI), C3 and C4 ( cranial nerve XI), C3 and C4 sensory componentsensory component

Rhomboid Major & Rhomboid Major & MinorMinor

RhomboidsRhomboids

Origin Origin Spinous processes of C7 Spinous processes of C7 through T5through T5

Insertion Insertion Medial border of scapula Medial border of scapula from level of spine to inferior anglefrom level of spine to inferior angle

Action Action Scapular retraction, Scapular retraction, elevation and downward rotationelevation and downward rotation

Innervation Innervation Dorsal scapular nerve Dorsal scapular nerve (C5)(C5)

Levator ScapulaeLevator Scapulae

Levator ScapulaeLevator Scapulae

Origin Origin Transverse processes of C1 - C4 Transverse processes of C1 - C4 vertebraevertebrae

Insertion Insertion Vertebral border of scapula Vertebral border of scapula between the superior angle and spinebetween the superior angle and spine

Action Action Scapular elevation and Scapular elevation and downward rotationdownward rotation

Innervation Innervation Third and fourth cervical Third and fourth cervical nerves and dorsal scapular nerve (C5)nerves and dorsal scapular nerve (C5)

Serratus AnteriorSerratus Anterior

Serratus AnteriorSerratus Anterior

Origin Origin Superolateral surfaces of Superolateral surfaces of upper 8 or 9 ribs at the side of chestupper 8 or 9 ribs at the side of chest

Insertion Insertion Vertebral border of Vertebral border of scapula, anterior surfacescapula, anterior surface

Action Action Scapular protraction and Scapular protraction and upward rotationupward rotation

Innervation Innervation Long thoracic nerve Long thoracic nerve (C5, C6, C7)(C5, C6, C7)

Pectoralis MinorPectoralis Minor

Pectoralis MinorPectoralis Minor

Origin Origin 3rd to 5th ribs, anterior 3rd to 5th ribs, anterior surfacesurface

Insertion Insertion Coracoid process of the Coracoid process of the scapulascapula

Action Action Scapular depression, Scapular depression, protraction, downward rotation, and protraction, downward rotation, and tilttilt

Innervation Innervation Medial pectoral nerve Medial pectoral nerve (C8, T1)(C8, T1)