Scapulothoracic Joint Muscles

Scapulothoracic Joint Muscles facts

- 5 muscles primarily involved in scapulothoracic joint movement. - All muscles originate on axial skeleton & insert on scapula and/or clavicle. - None attach to humerus & none cause glenohumeral joint movement. - All are essential in providing dynamic stability of the scapula so it can serve as a relative base of support for shoulder joint activities such as throwing, batting, and blocking.

Trapezius - Middle - Action

- Elevation - retraction - upward rotation

Scapulothoracic joint muscles

- Pec minor - Serratus Anterior - Levator Scapulae - Rhomboids - Trapezius (upper, middle, lower)

Levator Scapulae Action

- Scapular downward rotation - Scapular elevation

Rhomboids - Major & Minor Actions

- Scapular downward rotation - Scapular elevation - Scapular Adduction

serratus anterior action

- Scapular upward rotation - Scapular protraction

Scapulothoracic Joint fact

- not a true synovial joint, there is no ligamentous support

Pectoralis Minor Actions

- scapular protraction - scapular downward rotation - scapular depression - scapular abduction

Trapezius - Upper

Origin: Base of skull, occipital protuberance & posterior ligaments of neck. Insertion: Posterior lateral 3rd of clavicle. Innervation: Spinal Accessory Nerve

Serratus Anterior

Origin: Lateral ribs 1-9 Insertion: Anterior medial scapular border Innervation: Long Thoracic Nerve

Trapezius - Middle

Origin: Spinous Process of C7-T3. Insertion: Medial border of acromion process and superior border of scapular spine. Innervation: Spinal Accessory Nerve

Rhomboids - Major & Minor

Origin: Spinous Process of C7-T5. Insertion: Medial scapular border inferior to scapular spine. Innervation: Dorsal Scapular Nerve.

Trapezius - Lower

Origin: Spinous Process of T4-T12 Insertion: Base of scapular spine. Innervation: Spinal Accessory Nerve

Levator Scapulae

Origin: Transverse process of C1-C4. Insertion: Medial Scapular border from superior angle to scapular spine. Innervation: Dorsal Scapular Nerve.

Pectoralis Minor

Origin: anterior ribs 3-5 Inserts: coracoid Innervation: Medial Pectoral Nerve

Trapezius - Upper - Actions

Scapular: - Elevation -Upward rotation Neck: -Extension -Ipsilateral side bending