-
Throwing a baseball overhead
a. Latissimus Dorsi
-
Action: Extends, adducts, and medially rotates arm at shoulder joint; draws arm inferiorly and posteriorly.
-
Innervation: Thoracodorsal nerve
b. 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
c. Pectoralis Major
-
Action: Adduction 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
a. Biceps femoris
-
Action: Flexes leg at knee joint and extends thigh at hip joint
-
Innervation: Tibial and fibular nerves from sciatic nerves
b. Gastrocnemius
-
Action: Plantar flexes foot at ankle joint and flexes leg at knee joint
-
Innervation: Tibial nerve
c. Rectus femoris
-
Action: Extension of leg and flexes thigh at hip joint
-
Innervation: Femoral nerve
-
Doing sit-ups
-
Rectus abdominis
-
Action: Flexes the vertebral column, especially the lumbar portion. It also compresses the abdomen to aid in defecation, urination, forced exhalation and childbirth.
-
Innervation: Thoracic spinal nerves T7-T12
b. Transversus abdominis
-
Action: Compresses abdomen
-
Innervation: Thoracic spinal nerves T8-T12, iliohypogastric nerve and ilioinguinal nerve
c. External oblique
-
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 the iliohypogastric nerve
-
Breathing
a. 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)
b. Internal intercostals
-
Action: Contraction draws adjacent ribs together to further decrease anteroposterior and lateral dimensions of thoracic cavity during forced exhalation
-
Innervation: Thoracic spinal nerves T2-T12
c. External intercostals
-
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
References:
Tortora, G. J., & Derrickson, B. (2017). Principles of Anatomy and Physiology (15th ed.). John Wiley & Sons, Inc.