Shoulder Muscles

BIO 238Instructor: Dr. Gourdine

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Shoulder (Glenohumoral Joint)

Figure 8–2a

Scapula: Posterior Surface

Figure 8–3c

Scapula: Lateral View

Figure 8–3c

Scapula: Anterior Surface

Figure 8–3a

Humerus

Figure 8–4

Clavicle

Figure 8–2b, c

Thoracic (Rib) Cage

Figure 7–22a

ROM of the Shoulder

•Flexion•Extension•Horizontal Abduction•Horizontal Adduction•Abduction•Adduction•Lateral Rotation•Medial Rotation

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Shoulder Flexion and Extension

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Flexion Extension

Shoulder Horizontal Abduction and AdductionHorizontal Abduction Horizontal Adduction

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Shoulder Abduction and Adduction

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AdductionAbduction

Shoulder Medial and Lateral Rotation

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Lateral Rotation

Medial Rotation

ROM of the Scapula

•Abduction (protraction)•Adduction (retraction)•Depression•Elevation•Downward rotation •Upward rotation

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Adduction and Abduction of Scapula

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Adduction

Abduction

Depression and Elevation of Scapula

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Elevation Depression

Downward and Upward Rotation of ScapulaDownward Rotation Upward Rotation

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Muscles of the Upper Extremities: Brachium• Deltoid (pg 67)

▫ O-Lateral 1/3 of clavicle; Acromion; Spine of Scapula

▫ I-Deltoid tuberosity of humerus

▫ A- Moves the shoulder in the following ways: Abduction, flexion, medial rotation, horizontal adduction, extension, lateral rotation, horizontal abduction

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Figure 11-15a

Muscles of the Neck and Back• Trapezius (pg 69)

▫ O-External occipital protuberence, medial portion of superior nuchal line of occiput, ligamentum nuchae, spinous processes C7-T12

▫ I-Lateral 1/3 of clavicle, acromion; spine of scapula

▫ A- Head and neck: Extention,

lateral flexion to the same side, rotation to the opposite side.

Scapula: Elevation, upward rotation, adduction, stabilization, depression

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Figure 11–13a

Muscles of the Posterior Torso

Latissimus dorsi (pg 71)• O- Inferior angle of scapula,

spinous processes of last six thoracic vertebrae, last three or four ribs, thoracolumbar aponeurosis, and posterior iliac crest

• I-Intertubercular groove of humerus

• A-Extension, medial rotation and adduction of shoulder

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Figure 11–13a

Muscles of the Posterior Torso• Teres Major (pg 71)

▫ O-Inferior angle and lower 1/3 of lateral border of the scapula

▫ I-Crest of the lesser tubercle of the humerus

▫ A-Extension, medial rotation and adduction of humerus

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Figure 11–15b

Rotator Cuff

•Supraspinatus, infraspinatus, subscapularis, teres minor muscles

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Figure 11–15b

Muscles of the Posterior Torso

• Supraspinatus (pg 75)▫ O- supraspinous

fossa▫ I-Greater tubercle

of humerus▫ A-Abduction of

shoulder and stabilization of head of humerus

23Figure 11–15b

Muscles of the Posterior Torso

• Infraspinatus (pg 75)▫ O- infraspinous

fossa▫ I-Greater tubercle

of humerus▫ A- Lateral rotation

and adduction of shoulder, and stabilization of humerus

24Figure 11–15b

Muscles of the Posterior Torso• Teres Minor (pg 75)

▫ O-Upper axillary border of scapula

▫ I-Greater tubercle of humerus

▫ A-Lateral rotation and adduction of shoulder and stabilization of humerus

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Figure 11–15b

Muscles of the Anterior Torso• Subscapularis (pg 75)

▫ O- Subscapular fossa▫ I- Lesser tubercle of

humerus▫ A-Medial rotation of the

shoulder and stabilization of humerus

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Figure 11–15a

Muscles of the Posterior Torso• Rhomboid(eus) major

(pg 82)▫ O-Spinous processes T2-

5▫ I-Medial border of

scapula from root of spine to inferior angle

▫ A-Adduction (retraction), elevation, and downward rotation of scapula

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Figure 11–14a

Muscles of the Posterior Torso• Rhomboid(eus) minor

(pg 82)▫ O-Spinous processes C7

and T1▫ I-Upper portion of

medial border of scapula, and inferior angle

▫ A-Adduction (retraction), elevation, and downward rotation of scapula

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Figure 11–14a

Muscles of the Neck and Back• Levator scapulae (pg 84)▫ O-Transverse process C1-4▫ I-Medial border of scapula from

superior angle to superior portion of spine of scapula

▫ A- Elevation and downward rotation of

scapula Lateral flexion and rotation of head to the

same side

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Figure 11–13a

Muscles of the Anterior Torso• Serratus anterior (pg

86)▫ O-External surface of

ribs 1-8 or 9▫ I-Anterior surface of

vertebral border of scapula

▫ A- Abduction (protraction), upward rotation and depression of scapula; hold medial border of scapula against rib cage.

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Figure 11–13b

Muscles of the Anterior Torso• Pectoralis major (pg

89)▫ O- medial half of

clavicle; Sternum, cartilages of ribs 1-6

▫ I-Crest of greater tubercle of humerus

▫ A-Adduction, medial rotation, flexion, horizontal adduction, and extension of shoulder

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Figure 11–13b

Muscles of the Anterior Torso• Pectoralis minor (pg

92)▫ O- Ribs 3-5▫ I-Medial surface of

coracoid process of scapula

▫ A-Depression, abduction (protraction), downward rotation of scapula

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Figure 11–13b

Muscles of the Anterior Torso• Subclavius (pg 94)

▫ O-Rib 1 and costal cartilage

▫ I-Inferior shaft of clavicle, middle 1/3

▫ A-Depresses clavicle, stabilizes sternoclaviclar joint

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Figure 11–13b

Muscles of the Upper Extremities: Antebrachium - Anterior

• Coracobrachialis (pg 99)▫ O- Coracoid process of

scapula▫ I-Medial surface of

humeral shaft▫ A- Flexion and adduction

of shoulder

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Figure 11–16b