1. Throwing a baseball overhead
Deltoid
- Action: Lifts the arm away from the body, bends it at the shoulder, and straightens it out
- Innervation: Axillary nerve
Pectoralis major
- Action: Moves the arm outward, bends it, and extends it at the shoulder joint
- Innervation: Lateral and medial pectoral nerves
2. Kicking a ball
Quadriceps femoris
- Action: Extends the knee and flexes the hips
- Innervation: Femoral nerve
Gluteus maximus
- Action: Extend thigh at hip joint and laterally rotates thigh
- Innervation: Inferior gluteal nerve
3. Doing sit-ups
Rectus abdominis
- Action: Flexes the abdomen when sitting up
- Innervation: Lower six thoracoabdominal nerves
Abdominal obliques
- Action: Flexes the abdomen when sitting up
- Innervation: Thoracic spinal nerve and iliohypogastric nerve
4. Breathing
Diaphragm
- Action: Allow air into the lungs and enlarge the thoracic cavity
- Innervation: Phrenic nerve and lower intercostal nerves
External intercostals
- Action: Lifts the ribs to make more space in the chest or widen the thoracic cavity
- Innervation: Thoracic spinal nerves