Shoulder Girdle

Shoulder girdle


consists of three synovial articulations

  1. GLENOHUMERAL (GH) joint
  2. STERNOCLAVICULAR (SC) joint
  3. ACROMIOCLAVICULAR (AC) joint

and a fourth “functional” articulation, the SCAPULOTHORACIC joint, which is not a true anatomical joint


Muscles of the shoulder girdle


Summary of shoulder girdle movements during shoulder elevation “Shoulder elevation” or “elevation of the arm” (Smith, Weiss, & Lehmkuhl, 1996, p. 235) refers to a combination of movements that place the glenohumeral joint in either full flexion or abduction. Elevation involves glenohumeral movement in combination with scapulothoracic movement and thoracic extension.

From: http://moon.ouhsc.edu/dthompso/namics/shoulder.htm

Shoulder Girdle

Bones

  • 2 clavicles (acromial extremity, conoid tubercle, body, costal tuberosity, sternal extremity)

  • 2 scapula (a – anterior side, b – posterior side)

Joints

  • Glenohumeral – humerus articulating with glenoid fossa of scapula
  • Sternoclavicular (SC) – proximal clavicle articulating with manubrium and cartilage of rib 1
  • Acromioclavicular (AC) – acromian process of scapula articulating with distal clavicle
  • Coracoclavicular – coracoid process of scapula articulating with inferior clavicle
  • Scapulothoracic – anterior scapula articulating with thoracic wall

Movements of Scapula and Muscles Causing Movement:

  • Protraction (scapular abduction) – serratus anterior, pectoralis minor
  • Retraction (scapular adduction) – trapezius, rhomboid, levator scapulae
  • Downward Rotation – rhomboids, pectoralis minor
  • Upward rotation – trapezius, serratus anterior
  • Depression – trapezius (lower), pectoralis minor, subclavius
  • Elevation – trapezius (upper), levatro scapulae, rhomboid

Scpulohumeral Rhythm– a regular pattern of scapular rotation that accompanies and facilitates humeral abduction
        *beyond 30 degrees abduction, 1 degree scapular rotation for 2 degrees of humerus elevationMuscles (all have origins on axial skeleton with insertions on scapula or clavicle)

Muscle Origin Insertion Action Palpate
Trapezius occipital, C7-T12 posterior clavicle, acromian process, scapular spine elevate scapula, extend head, upward rotation, adduction, depression up and down posterior neck to T12, spine to scapula
Levator Scapulae C1-C4 medial border of scapula above spine elevate scapula deep to trapezius
Rhomboid C7-T5 medial scapula below spine elevate and retract scapula deep to trapezius
Serratus Anterior upper 9 ribs anterior border of scapula protraction and upward rotation front and lateral chest
Pectoralis Minor ribs 3-5 coracoid process protraction, downward rotation, depression under pectoralis major
Subclavius rib 1 “subclavian” groove of clavicle depression not palpable

From: http://academic.wsc.edu/faculty/jatodd1/351/ch7outline.html

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6 thoughts on “Shoulder Girdle”

  1. saya mengambil gambar” buat tugas saya anatomi lo bisa bantu saya lo d ilmu tambahan bisa gak kirim ke website saya.trimakasih.

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