OIAs Muscles that move the Upper Arm (5)

Question 1

1) Flexors -
i. Pectoralis major

Answer 1

1. O: clavicle, sternum, costal cartilages of upper ribs
2. I: intertubercular groove of humerus
3. A: adducts and medially rotates arm

Question 2

2. Extensors -i. Latissimus Dorsi: Power stroke muscle

Answer 2

1. O: spines of sacral & lumbar vertebrae, iliac crest
2. I: intertubercular groove of humerus
3. A: extends & adducts and medially rotates upper arm, pulls back in
   swimming & rowing

Question 3

2. Extensors- ii. Teres major

Answer 3

1. O: lateral scapula
2. I: lesser tubercle of humerus
3. A: extends, adducts and medially rotates arm

Question 4

3. Abductors
   i. Deltoid

Answer 4

1. O: acromion process & spine of scapula, clavicle
2. I: deltoid tuberosity of humerus
3. A: Abducts, extends and laterally rotates arm