1. Throwing a baseball overhead
a. Teres major
- Action: extends arm at the shoulder joint; assist in adduction and medial rotation of the arm
- Innervation: lower subscapular nerve (C5-C7)
b. Deltoid
- Action: anterior head (flexes and internally rotates arm), middle head (abducts arm), posterior head (laterally rotates arm and extends it)
- Innervation: axillary nerve (C5, C6)
2. Kicking a ball
a. Gastrocnemius
- Action: knee flexion, ankle plantar flexion
- Innervation: tibial nerve (S1, S2)
b. Rectus femoris
- Action: extension of leg at knee joint and flexes thigh at hip joint
- Innervation: femoral nerve (L2-L4)
3. Doing sit-ups
a. Rectus abdominis
- Action: assisting the flat muscles in compressing the abdominal viscera; flexes the pelvis and vertebral column and depresses the ribs
- Innervation: thoracic spinal nerves (T7-T12) which are intercostal nerves (T7-T11), subcostal nerve (T12)
b. Transversus abdominis
- Action: compression of abdominal contents
- Innervation: intercostal nerves (T7-T11), subcostal nerve (T12), iliohypogastric nerve (L1), ilioinguinal nerve (L1)
4. Breathing
a. Rectus abdominis
- Action: assisting the flat muscles in compressing the abdominal viscera; flexes the pelvis and vertebral column and depresses the ribs
- Innervation: thoracic spinal nerves (T7-T12) which are intercostal nerves (T7-T11), subcostal nerve (T12)
b. Diaphragm
- Action: depressed costal cartilages; primary muscle for breathing
- Innervation: phrenic nerves (C3-C5)
References:
Tortora, G. J., & Derrickson, B. (2017). Principles of Anatomy and Physiology (15th ed.) [Online]. https://handoutset.com/wp-content/uploads/2022/05/Principles-of-anatomy-and-physiology-Wiley-2017-Derrickson-Bryan-H._-Tortora-Gerard-J..pdf