1) Throwing a baseball overhead
a) Deltoid
- Action: Arm abduction, shoulder flexion, and medial rotation to throw
- Innervation: Axillary nerve
b) Pectoralis major
- Action: Arm adduction, arm internal rotation, arm flexion, arm extension
- Innervation: Medial and lateral pectoral nerve
2) Kicking a ball
a) Gluteus maximus
- Action: Extends thigh at hip joint and laterally rotates thigh
- Innervation: Inferior gluteal nerve
b) Quadriceps femoris
- Action: Knee extension, which propels the leg forward to kick
- Innervation: Femoral nerve
3) Doing sit-ups
a) Rectus abdominis
- Action: Lifts torso towards legs
- Innervation: Thoracoabdominal nerves
b) External obliques
- Action: Stabilizes core through trunk flexion and rotation
- Innervation: Thoracic spinal nerves
4) Breathing
a) Diaphragm
- Action: Contraction increases thoracic cavity volume
- Innervation: Phrenic nerve
b) Intercostal muscles
- Action: Lifts and expands rib cage for exhalation
- Innervation: Intercostal nerves