I. Throwing a baseball overhead
1. SUBSCAPULARIS
a. Action: The precise action of subscapularis is to internally rotate the arm on the shoulder joint. Shoulder joint: Arm internal rotation; Stabilizes humeral head in glenoid cavity
b. Innervation: Subscapularis is innervated by the upper and lower subscapular nerves (C5-C6), that stem from the superior and posterior cords of the brachial plexus, respectively.
2. LATISSIMUS DORSI
a. Action: Extension, adduction and medial rotation of the upper limb at the shoulder.
b. Innervation: The innervation is carried by the thoracodorsal nerve (C6-C8), a branch of the brachial plexus.
II. Kicking a ball
1. QUADRICEPS FEMORIS
a. Action: Extension of the knee joint. Contributes to flexion at the hip joint through the action of the rectus femoris.
b. Innervation: Femoral nerve
2. HAMSTRINGS
a. Action: Flexion of the leg at the knee joint. Extension of thigh at the hip. Medially rotates the thigh at the hip joint and the leg at the knee joint.
b. Innervation: Tibial part of the sciatic nerve.
III. Doing sit-ups
1. RECTUS ABDOMINIS
a. Action: As well as assisting the flat muscles in compressing the abdominal viscera, the rectus abdominis also stabilises the pelvis during walking, and depresses the ribs.
b. Innervation: Thoracoabdominal nerves (T7-T11).
2. TRANSVERSUS ABDOMINIS
a. Action: Compression of abdominal contents.
b. Innervation: Thoracoabdominal nerves (T7-T11), subcostal nerve (T12) and branches of the lumbar plexus.
IV. Breathing
1. INTERNAL INTERCOSTAL MUSCLES
a. Action: Depress ribs during forced expiration; Support intercostal spaces and thoracic cage
b. Innervation: Intercostal nerves
2. STERNOCLEIDOMASTOID MUSCLE
a. Action: The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck.
b. Innervation: The sternocleidomastoid is innervated by the accessory nerve. Accessory nerve (CN XI), branches of cervical plexus (C2-C3)
References:
The Ultimate Resource for Healthcare Professionals & Medical Students. TeachMeAnatomy. (n.d.). https://teachmeanatomy.info/
Tortora, G. J., & Derrickson, B. (2017). Principles of anatomy and physiology. Wiley Custom Learning Solutions.