1. Throwing a baseball overhead
- Deltoid
- Action: The lateral fibers abduct (move away from midline) at shoulder joint while the anterior fibers flex and medially rotate the arm at shoulder joint. Posterior fibers extend and laterally rotate the arm at shoulder joint.
- Innervation: Axillary nerve
- Supraspinatus
- Action: Simply assists the Deltoid muscle in moving the arm at shoulder joint away from midline.
- Innervation: Suprascapular nerve.
2. Kicking a ball
- Vastus lateralis
- Action: Extends leg at knee joint.
- Innervation: Femoral nerve
- Psoas Major
- Action: (along with iliacus muscles) Flex thigh at hip joint and rotate it laterally.
- Innervation: Lumbar spinal nerves L2-L3
3. Doing sit-ups
- Rectus abdominis
- Action: Flexes the vertebral column especially the lumbar portion. It also compresses abdomen to aid in several exercises such as defecation, urination, childbirth, etc.
- Innervation: Thoracic spinal nerves T7-T12
- Transversus abdominis
- Action: Simply compresses the abdomen.
- Innervation: Thoracic spinal nerves T8-T12, iliohypogastric nerve, and ilioinguinal nerve
4. Breathing
- Diaphragm
- Action: When the Diaphragm contracts, it flattens which increases the vertical dimension of the thoracic cavity. This results in inhalation. On the other hand, when the Diaphragm relaxes, it moves superiorly which decreases the vertical dimension in the thoracic cavity. This results in exhalation.
- Innervation: Phrenic nerve - contains axons from cervical spinal nerves (C3 - C5)
- Internal intercostals
- Action: When it contracts, it draws the adjacent ribs together to further decrease the anteroposterior and lateral dimensions of the thoracic cavity. In simple terms, it shrinks the diameter of the thoracic cavity which helps push air out of the lungs.
- Innervation: Thoracic spinal nerves T2-T124.
References:
- Dale, P., & Pashley, T. (n.d.). The Muscles and Body Parts Needed to Kick a Football. Livestrong. Retrieved September 8, 2023, from https://www.livestrong.com/article/354537-the-muscles-body-parts-needed-to-kick-a-football/
- Tortora, G. J., & Derrickson, B. (2017). "Chapter 11: The Muscular System". Principles of Anatomy & Physiology (15th ed., pp. 341 - 342). [Print]. John Wiley & Sons Inc.
- Tortora, G. J., & Derrickson, B. (2017). "Chapter 11: The Muscular System". Principles of Anatomy & Physiology (15th ed., pp. 341 - 342). [Print]. John Wiley & Sons Inc.