1. Throwing a baseball overhead
- Subscapularis
- Action - Internally rotates and adducts the humerus
- Innervation - Upper and lower subscapular nerve
- Deltoid
- Action - Lateral fibers abduct arm at shoulder joint; anterior fibers flex and medially rotate arm at shoulder joint; posterior fibers extend and laterally rotate arm at shoulder joint
- Innervation - Axillary nerve
2. Kicking a ball
- Gastrocnemius
- Action - Plantar flexion at the ankle joint and flexion of leg at knee joint
- Innervation - Tibial nerve
- Soleus
- Action - Plantar flexion at the ankle joint
- Innervation - Tibial nerve
3. Doing sit-ups
- Transversus abdominis
- Action - Compresses the abdomen
- Innervation - Lower intercostal nerves (thoracoabdominal, nerve roots T7-T11), the iliohypogastric nerve and the ilioinguinal nerve
- Rectus Abdominis
- Action - Primarily flexes the lumbar spine, thus bringing the ribcage closer to the pelvis; assists in stabilizing the pelvis and maintaining posture; plays a key role in supporting the abdominal organs and protecting the spinal column
- Innervation - Thoracic spinal nerves (T7 - T12)
4. Breathing
- Diaphragm
- Action - Contraction makes itself flat and increases the vertical dimensions which causes inhalation, while its relaxation allows itself to move superiorly, as well as decreases the vertical dimension of the thorax, which results in exhalation
- Innervation - Phrenic nerve, carrying axons from cervical spinal nerves (C3–C5)
- External intercostals
- Action - Elevates the ribs, which results in inhalation; while, it depresses the rib cage, which causes exhalation
Innervation - Thoracic spinal nerves (T2–T12)
- Action - Elevates the ribs, which results in inhalation; while, it depresses the rib cage, which causes exhalation
Reference:
Tortora, G. J., & Derrickson, B. (2017). Principles of anatomy and physiology. Wiley Custom Learning Solutions.