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Origin: Lateral epicondyle of humerus via the Common extensor origin.
Insertion: External expansion to middle and distal phalanges by four tendons.
Actions: Extends fingers at all joints.
Innervation: C7, C8 Posterior interosseous
Daily uses: Opening fingers to hold jar.
Other muscles of the Upper Limb
Origin: Posterior surface of the scapula (below the spine of the scapula) .
Insertion: Greater tuberosity on the humerus .
Actions: Shoulder abduction, External rotation.
Innervation: Suprascapular nerve .
Daily uses: Brushing hair.
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: 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