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Origin: Angles of third to sixth ribs.
Insertion: Transverse processes of fourth, fifth, and sixth cervical vertebrae (C4-6).
Actions: Bilateral action extends the spine. Unilateral contraction laterally flexes the vertebral column.
Innervation: Dorsal rami of cervical spinal nerves .
Daily uses: Maintaining straight spine in standing.
Origin: Supraspinous fossa
Insertion: Greater tuberosity of the humerus
Actions: Abduction Stabilisation of the humerus
Innervation: Suprascapular nerve
Daily uses: Holding shopping bags away from the body
Origin: Mid section of the lateral border of the scapula
Insertion: Greater tuberosity on the humerus
Actions:External rotation, Shoulder adduction
Innervation: Axillary nerve
Daily uses: Brushing hair
Origin: Anterior (costal) surface of the scapula
Insertion: Lesser tuberosity of the humerus
Actions: Internal rotation , Adduction
Innervation: Upper and lower subscapular nerves
Daily uses: Tucking the back of your shirt into your trousers