1. Throwing a baseball overhead
Muscle: Subscapularis
Action: Adducts and rotates the humerus
Innervation: Upper and lower subscapular nerves (C5-C6)
Muscle: Deltoid
Action: Abducts, extends, and medially and laterally rotates arm at glenohumeral joint
Innervation: Axillary nerve (C5-C6)
2. Kicking a ball
Muscle: Quadriceps femoris
Action: Extends the leg at the knee joint and flex the thigh at the hip joint
Innervation: Femoral nerve
Muscle: Hamstring
Action: Flexes the knee and extends the hip
Innervation: Sciatic nerve (L4-S3)
3. Doing sit-ups
Muscle: Rectus abdominis
Action: Flexes the trunk
Innervation: Thoracoabdominal nerves
Muscle: Transverse Abdominis
Action: Stabilizes the trunk
Innervation: Lower intercoastal nerves, iliohypogastric and ilioinguinal nerves
4. Breathing
Muscle: Diaphragm
Action: Primary muscle of inspiration
Innervation: Phrenic nerves (C3-C5) and lower intercostal nerves
Muscle: External intercoastal muscles
Action: Elevate ribs at their costovertebral joints
Innervation: Adjacent intercostal nerves