Throwing a baseball overhead:
- Deltoid Muscle
- Action: Abducts the arm and assists in shoulder flexion and extension.
- Innervation: Axillary nerve
- Pectoralis Major
- Action: Adducts and medially rotates the arm; also assists in shoulder flexion.
- Innervation: Lateral and medial pectoral nerves
Kicking a ball:
- Quadriceps Femoris
- Action: Extends the knee.
- Innervation: Femoral nerve
- Iliopsoas (including Psoas Major and Iliacus)
- Action: Flexes the hip.
- Innervation: Femoral nerve (for Iliacus) and lumbar plexus for Psoas Major
Doing sit-ups:
- Rectus Abdominis
- Action: Flexes the trunk (bends the torso forward).
- Innervation: Lower six thoracoabdominal nerves and subcostal nerve
- External Oblique
- Action: Flexes and rotates the trunk; helps compress the abdominal contents.
- Innervation: Lower six thoracoabdominal nerves and subcostal nerve
Breathing:
- Diaphragm
- Action: Contracts to increase the thoracic cavity volume, causing inhalation.
- Innervation: Phrenic nerve
- External Intercostals
- Action: Elevates the ribs during inhalation.
- Innervation: Intercostal nerves