-
Throwing a baseball overhead
Muscle: Deltoid
Action: Lateral fibers abduct arm at shoulder joint; anterior fibers flex and medially rotate arm at shoulder joint; posterior fibers extend and laterally rotate arm at shoulder joint.
Innervation: Axillary nerve
Muscle: Pectoralis major
Action: As a whole, adducts and medially rotates arm at shoulder joint; clavicular head flexes arm, and sternocostal head extends flexed arm to side of trunk.
Innervation: Medial and lateral pectoral nerves
-
Kicking a ball
Muscle: Biceps femoris
Action: flexes leg at knee joint and extends thigh at hip joint
Innervation: tibial and fibular nerves from sciatic nerve
Muscle: Rectus Femoris
Action: all four heads extend leg at knee joint; rectus femoris muscle acting alone also flexes thigh at hip joint
Innervation: femoral nerve
-
Doing sit-ups
Muscle: Rectus abdominis
Action: Flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth; RMA: flexes pelvis on the vertebral column
Innervation: Thoracic spinal nerves T7-T12
Muscle: External obliques
Action: Acting together (bilaterally), compress abdomen and flex vertebral column, acting singly (unilaterally), laterally flex vertebral column, especially lumbar portion, and rotate vertebral column
Innervation: Thoracic spinal nerves t7-t12 and iliohypogastric nerve
-
Breathing
Muscle: External intercostal
Action: Contraction elevates ribs and increases anteroposterior and lateral dimensions of thoracic cavity, resulting in inhalation; relaxation depresses ribs and decreases anteroposterior and lateral dimensions of thoracic cavity, resulting in exhalation.
Innervation: Thoracic spinal nerves T2–T12.
Muscle: Diaphragm
Action: contraction of diaphragm causes it to flatten and increases vertical dimension of thoracic cavity resulting in inhalation; relaxation of diaphragm causes it to move superiorly and decreases vertical dimension of thoracic cavity, resulting in exhalation
Innervation: phrenic nerve, which contains axons from cervical spinal nerves c3-c5
REFERENCE:
Tortora, G. J., & Derrickson, B. (2017). Principles of anatomy & physiology. Fifteenth edition; Wiley Loose-Leaf Print Companion. Hoboken, New Jersey, John Wiley & Sons, Inc.