Anatomy, back, scapula (2023)


The scapula, or scapula, is the bone that connects the collarbone to the humerus. The shoulder blade forms the rear part of the shoulder girdle. It is a strong, flat, and triangular bone. The shoulder blade attaches to several muscle groups. The intrinsic muscles of the scapula include the rotator cuff, teres major, subscapularis, teres minor, and infraspinatus muscles. These muscles attach the scapular surface and assist in abduction and external and internal rotation of the glenohumeral joint. Extrinsic muscles include triceps, biceps, and deltoids. The third muscle group includes the levator scapulae, trapezius, rhomboids, and serratus anterior. These muscles are responsible for the rotational and stabilizing movements of the scapula.

structure and function

The shoulder blade is an important bone for the function of the shoulder joint. Participates in 6 types of movement and allows for fully functional upper limb movement including protraction, retraction, elevation, depression, upward rotation and downward rotation. Protraction is achieved through the action of the serratus anterior, pectoralis major, and pectoralis minor muscles. Retraction is achieved through the action of the trapezius, rhomboid, and latissimus dorsi muscles. Elevation is accomplished by the trapezius, levator scapulae, and rhomboid muscles. The depression is achieved through gravity and the actions of the latissimus dorsi, serratus anterior, pectoralis major and minor, and trapezius muscle. The upward rotation is performed by the trapezius and serratus anterior muscles. Downward rotation is accomplished through gravity, the latissimus dorsi, levator scapulae, rhomboids, and pectorals major and minor. Through these six movements, the scapula enables full function of the shoulder joint, one of the most mobile and versatile joints in the human body. An example of the importance of scapular movement in full range of motion of the upper limb is that of the winged scapula (see Clinical significance), in which paralysis of the serratus anterior or trapezius prevents raising of the upper limb above the level of the scapula. the shoulder.


Osteogenic development of the scapula begins by endochondral ossification at week 11 of human embryogenesis. This occurs just after the 10th week of development of the humerus, when it forms the glenohumeral joint.

blood and lymph supply

The blood supply to the scapula is complex due to its position and function as a critical component of the shoulder joint and the need for adaptability. It is largely supplied by an anastomosis between the axillary and subclavian artery known as the scapular anastomosis. The arteries contributing to this anastomosis are the dorsal scapular artery, the suprascapular artery, the deep scapular artery, the circumflex scapular branch of the subscapular artery, and the medial anastomoses with the intercostal arteries. The scapular anastomosis allows collateral blood flow in the supine position and when using the shoulder in its various positions.

The venous drainage of the scapula is mainly via the axillary vein, the suprascapular veins and numerous small and very variable anastomotic tributaries.

The lymphatic drainage from the right shoulder blade empties into the right lymphatic duct and the thoracic duct of the left shoulder blade. Lymph nodes associated with the scapula include the axillary and supraclavicular lymph nodes.


The nerves of the scapula include the dorsal scapular nerves, superior and inferior subscapular, and suprascapular nerves, which arise from the brachial plexus at the root of the C5 anterior branch, posterior spinal cord, and superior trunk, respectively. See the Muscles section below for more details on specific muscle innervations.


The intrinsic muscles of the scapula attach directly to the bone surface. These muscles are the four limbs of the rotator cuff and stabilize the glenohumeral joint. These include:


  • Function: Initiation of arm abduction (first 15 degrees), glenohumeral joint stabilization

  • Origin: Fossa supraspinale

  • Insertion: Upper part of the greater tuberosity

  • Innervation: N. suprascapularis (C5, C6)


  • Function: Lateral rotation of the arm, stabilizes the glenohumeral joint

  • Origin: Infraspinal Fossa

  • Insertion: Greater tuberosity of the humerus, between the supraspinatus and the insertion of the teres minor

  • Innervation: N. suprascapularis (C5, C6)

teres Moll

  • Function: Lateral rotation of the arm, stabilizes the glenohumeral joint

  • Origin: Lateral/axillary border and adjacent posterior aspect of scapula

  • Insertion: Underside of the greater tuberosity of the humerus

  • Innervation: N. axillaris (C5, C6)

sub-shoulder blade

(Video) Muscles of the Back | Anatomy Model

  • Function: Adduction and medial rotation of the arm, stabilize the glenohumeral joint

  • Origin: subscapular fossa

  • Insertion: small tuberculum humerus

  • Innervation: N. subscapularis (C5, C6, C7)

The extrinsic muscles of the scapula attach to the processes of the scapula and affect movement at the glenohumeral joint: These include:

Brachial biceps

  • Function: Resists shoulder dislocation, greater forearm flexor, forearm supination

  • Origin:

    • Short head: Processus coracoideus

    • Langer Kopf: Tuberculum supraglenoidale

  • Insertion: tuber radialis and forearm fascia (as biceps fascia)

  • Innervation: Musculocutaneous Nerv (C5, C6)

Trizeps brachii

  • Function: Resists dislocation of the shoulder, main extensor of the forearm

  • Origin:

    • Lateral head: above the radial groove,

    • Medial head: below the radial groove

    • Long head: infraglenoid tubercle of scapula

  • Insertion: olecranon process of the ulna and fascia of the forearm

  • Innervation: N. radialis (C6, C7, C8)


  • Function:

    • The anterior aspect is responsible for flexion and medial rotation of the arm.

    • The midface is responsible for the abduction of the arm (up to 90 degrees)

    • The posterior aspect is responsible for extension and lateral rotation of the arm.

  • Origin: Lateral clavicle, acromion and scapular spine.

  • Insertion: deltoid tubercle

    (Video) Scapula Anatomy

  • Innervation: N. axillaris (C5, C6)

The stabilizing muscles of the scapula include:


  • Function:

    • The superior fibers elevate and rotate the scapula during arm abduction (90 to 180 degrees)

    • The middle fibers pull the scapula back.

    • The lower fibers pull the shoulder blade down.

  • Origin: Skull, nuchal ligament and spinous processes from C7 to T12

  • Insertion: clavicle, acromion and scapular spine

  • Innervation: N. accessorius (Hirnnerv XI)

shoulder lift

  • Function: raises the shoulder blade

  • Origin: Transverse processes of vertebrae C1 to C4

  • Insertion: medial edge of scapula

  • Innervation: C3, C4 and dorsal scapular nerve (C5)

serrated front

  • Function: Fixes the scapula to the chest wall and supports arm rotation and abduction (90 to 180 degrees)

  • Origin: Surface of the upper eight ribs lateral to the thorax

  • Insertion: Along the entire anterior length of the medial border of the scapula

  • Innervation: longer thoracic nerve (C5, C6, C7)

Diamond major

  • Function: retracts and rotates the scapula

  • Origin: spinous processes of vertebrae T2 to T5

  • Insertion: inferomedial border of the scapula

  • Innervation: Dorsal scapular nerve (C5)

small diamonds

  • Function: retracts and rotates the scapula

  • Origin: spinous processes of vertebrae C7 to T1

  • Insertion: medial edge of scapula

    (Video) Dissection of back showing trapezius, levator scapulae, rhomboidis minor and major

  • Innervation: Dorsal scapular nerve (C5)

Other muscles attached to the scapula are:

The widest des Rückens

  • Function: Extends, adds, and medially rotates the upper limb

  • Origin: Spinous processes from T6 to T12, iliac crest, thoracolumbar fascia, lower three ribs and inferior angle of scapula

  • Insertion: intertubercular ditch of the humerus

  • Innervation: Thorakodorsalnerv (C6, C7, C8)

teres major

  • Function: Adduction and medial rotation of the arm.

  • Origin: Posterior surface of the scapula at its lower angle

  • Insertion: intertubercular groove on its medial side

  • Innervation: inferior scapular nerve (C5, C6)

small pectoral muscle

  • Function: depression of the shoulder, protraction of the scapula

  • Origin: Third, fourth, fifth ribs near their respective costal cartilages

  • Ansatz: Coracoid process

  • Innervation: N. pectoralis medialis (C8, T1)


  • Function: flexion and adduction of the arm.

  • Herkunft: Coracoid process

  • Insertion: mid-humerus, on its medial side

  • Innervation: Musculocutaneous Nerv (C5, C6, C7)


  • Function: pulls the hyoid bone down, active when speaking and swallowing

  • Origin: upper edge of shoulder blade

  • Insertion: Lower border of the hyoid bone

  • Innervation: Ansa cervicalis (C1, C2, C3)

Physiological variants

the acromial -Unfused center of secondary ossification in the acromion that can cause pain and tenderness. It is believed to increase the risk of rotator cuff impingement and tears. Initial treatment can be conservative, but in refractory cases, surgical excision of the unfused fragment is an option.[1]

Sprengel deformity -Congenital elevation of the scapula, leading to a decrease in the functionality of the scapula and upper limb. Surgical reconstruction is the usual approach to correct the aesthetics and functionality of the scapula. This is a rare condition, but it is the most common variant of the scapula.[2]

(Video) Scapula

surgical considerations

In cases of severe shoulder arthritis, malignancy, or other indications for total shoulder arthroplasty, the scapula becomes important. The socket and labrum that form the scapular portion of the joint must be replaced with an artificial component. In addition, the surgeon should perform a preoperative evaluation of the glenoid version in relation to the scapular axis and scapular inclination using radiological methods such as computed tomography to reduce surgical complications and ensure optimal implantation of the prosthesis.[3]The positioning of the glenoid ridge has also been shown to be important in determining the amount of bone mass that can be used for anchor positioning for prosthesis delivery during arthroplasty.[4]During total shoulder arthroplasty, there is a significant axillary nerve risk during deltoid dissection. A study has shown a linear correlation between the distance between the acromion and the axillary nerve and arm length, allowing for better prediction of axillary nerve location.[5]

clinical importance

The shoulder blade is a strong bone and protects the upper back of the rib cage. Scapula fractures are rare and indicate severe trauma. Scapular flapping can occur after an injury to the long thoracic nerve or the accessory nerve of the spine. The long thoracic nerve can be injured during axillary dissection, trauma, or thoracotomy.[6]The accessory nerve can be injured during surgery or from neck trauma. In the case of a winged scapula, a relevant finding on physical examination would be posterior protrusion of the scapula on the affected side when a posterior extension force is applied. upper extremity, e.g. For example, when you press yourself against a wall with your arm bent at 90 degrees. The thoracodorsal nerve can also be injured iatrogenically during thoracic or axillary surgery because it runs close to the anterior surface of the scapula. A sign of a thoracodorsal nerve injury is paralysis of the ipsilateral latissimus dorsi muscle, resulting in an inability to actively push the shoulder. Injury to the dorsal scapular nerve should be suspected when the scapula is more lateral to the midline on one side of the body compared to the contralateral side. This lesion causes paralysis of the ipsilateral rhomboid muscles.[7]

Shoulder impingement syndrome can result in abnormal shoulder blade function. Dyskinesia and abnormal movements of the shoulder can result from dysfunctional movements of the scapula. In rare cases, the scapula can become pinched between the ribs after a high thoracotomy.[8]In such cases, it may be necessary to revise the base of the scapula.

The scapula also provides an attachment point for the ligaments that connect the acromion to the clavicle and the coracoid process to the clavicle. These ligaments, the acromioclavicular and coracoclavicular ligaments, can be injured in a fall directly onto the shoulder or in other traumatic impacts that cause shoulder separation. This is a common injury that varies in severity depending on the severity of the ligament injury.[9]

A case study was conducted in a patient who presented with a triad of humeral fracture, scapular fracture, and traumatic anterior dislocation of the humerus. It is rare for these three injuries to occur together. The case report indicated that open reduction and internal fixation of the fracture should be performed before reducing the dislocation to reduce the risk of neurovascular compromise.[10]


Scapula, development plan, seven centers, vertebral border, acromion, coracoid process. Contributed by Gray's Anatomy Plates



Hurst SA, Gregory TM, Reilly P. Os acromiale: a review of its incidence, pathophysiology, and clinical management.EFFORT Open Rev.August 2019;4(8):525-532.[PMC-free item: PMC6719606] [PubMed: 31538003]


Pargas C, Santana A, Czoch WL, Rogers KJ, Mackenzie WG. Sprengel deformity in biological sisters.J Am Acad Orthop Surg Glob Res Rev.April 2020;4(4)[PMC-free item: PMC7188265] [PubMed: 32377613]


Fulin P, Kysilko M, Pokorny D, Padr R, Kasprikova N, Landor I, Sosna A. Scapular inclination variability and glenoid version study-considerations for preoperative planning: clinical radiological study.BMC Musculoskeletal Disorder.14 January 2017;18(1):16.[PMC-free item: PMC5237552] [PubMed: 28088244]


Wang S, Wang J, Gu C, Zuo J. [An anatomical study of the glenoid fossa in relation to the position and direction of anchor attachment].Zhonghua Wai Ke Za Zhi.February 2015;53(2):90-4.[PubMed: 25908279]


Samart S, Apivatgaroon A, Lakchayapakorn K, Chemchujit B. The correlation between acromion-axillary distance and humerus length; a cadaver study.J Med Assoc.August 2014;97 Supplement 8S27-33:[PubMed: 25518290]


Noland SS, Krauss EM, Felder JM, Mackinnon SE. Surgical and clinical decision making in isolated long thoracic nerve palsy.Hand (NY).November 2018;13(6):689-694.[PMC free item: PMC6300170] [PubMed: 28975819]


Muir B. Neuropathy of the dorsal shoulder nerve: a narrative review of the literature.J Can Chiropr Assoc.August 2017;61(2):128-144.[PMC-free item: PMC5596970] [PubMed: 28928496]


Zaidenberg EE, Rossi LA, Bongiovanni SL, Tanoira I, Maignon G, Ranalletta M. Snapping scapular syndrome secondary to an intramedullary rib fixation device.Int J Surg Caso Rep.2015;17:158-60.[PMC-free item: PMC4701874] [PubMed: 26629853]


Bonz J, Tinloy B. Assessment and management of the shoulder and humerus in the emergency department.Emerg Med Clinic North Am.Mayonnaise 2015;33(2):297-310.[PubMed: 25892723]


Farooque K, Khatri K, Dev C, Sharma V, Gupta B. Injury mechanism and management in traumatic anterior shoulder dislocation with concurrent humeral shaft and ipsilateral scapula fracture: a case report and review of the literature.J With case representativeDecember 16, 2014;8:431.[PMC free article: PMC4301949] [PubMed: 25511744]


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