1. Throwing a baseball overhead
Muscle 1: Subscapularis
Action: Medially rotates arm at shoulder joint.
Innervation: Upper and lower subscapular nerve.
Muscle 2: Latissimus Dorsi
Action: Extends, adducts, and medially rotates arm at shoulder joint; draws arm inferiorly and posteriorly. RMA: Elevates vertebral column and torso.
Innervation: Thoracodorsal nerve.
2. Kicking a ball
Muscle 1: Biceps femoris
Action: Flexes leg at knee joint and extends thigh at hip joint.
Innervation: Tibial and fibular nerves from sciatic nerve.
Muscle 2: Semitendinosus
Action: Flexes leg at knee joint and extends thigh at hip joint.
Innervation: Tibial nerve from sciatic nerve.
3. Doing sit-ups
Muscle 1: Rectus abdominis
Action: Flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth. RMA: Flexes pelvis on the vertebral column.
Innervation: Thoracic spinal nerves T7–T12.
Muscle 2: Transversus abdominis
Action: Compresses abdomen.
Innervation: Thoracic spinal nerves T8–T12, iliohypogastric nerve, and ilioinguinal nerve.
4. Breathing
Muscle 1: Diaphragm
Action: Contraction of diaphragm causes it to flatten and increases vertical dimension of thoracic cavity, resulting in inhalation; relaxation of diaphragm causes it to move superiorly and decreases vertical dimension of thoracic cavity, resulting in exhalation.
Innervation: Phrenic nerve, which contains axons from cervical spinal nerves (C3–C5).
Muscle 2: External intercostals
Action: Contraction elevates ribs and increases anteroposterior and lateral dimensions of thoracic cavity, resulting in inhalation; relaxation depresses ribs and decreases anteroposterior and lateral dimensions of thoracic cavity, resulting in exhalation.
Innervation: Thoracic spinal nerves T2–T12.
Reference:
Tortora, G. J., & Derrickson, B. (2016). Chapter 11: The Muscular System. In Principles of Anatomy and Physiology (15th edition). Wiley. Retrieved from https://www.google.com.ph/url?sa=i&rct=j&q=&esrc=s&source=web&cd=&ved=0CAIQw7AJahcKEwi4m_OvkpuBAxUAAAAAHQAAAAAQAg&url=https%3A%2F%2Fhandoutset.com%2Fwp-content%2Fuploads%2F2022%2F05%2FPrinciples-of-anatomy-and-physiology-Wiley-2017-Derrickson-Bryan-H._-Tortora-Gerard-J..pdf&psig=AOvVaw3MGogf51os64NiWCtHEzVc&ust=1694266926809150&opi=89978449.