1. Throwing a baseball overhead
Muscles: a. Deltoid muscle b. Rotator cuff muscle
Action: a. To abduct and flex the shoulder joint.
b. Contracts to stabilize the shoulder joint and assist in the initial phase of raising the arm.
Innervation: a. Primarily innervated by the axillary nerve, a branch of the brachial plexus
b. By the suprascapular nerve, which is also derived from the brachial plexus
2. Kicking a ball: Quadriceps femoris, Hamstring muscles
Muscles: a. Quadriceps femoris b. Illiopsoas
Action: a. Contracts to extend the knee joint.
b. Responsible for flexing the hip joint. Also helps in stabilizing the trunk during the kicking motion.
Innervation: a. The quadriceps muscles are primarily innervated by the femoral nerve.
b. Innervated by the lumbar plexus, primarily the femoral nerve and the branches of the lumbar nerves.
3. Doing sit-ups
Muscles: a. Rectus abdominis b. External Oblique Muscles
Action: a. Flexing the Lumbar spine
b. Trunk flexion
Innervation: Both innervated in the lower six thoracoabdominal nerves and the subcostal nerve
4. Breathing
Muscles: a. Diaphragm b. Intercostal muscles
Action: a. Primary muscle of respiration
b. Aids in the process of inhalation
Innervation: Innervated by the intercostal nerves, which originate from the thoracic spinal nerve