- Throwing a baseball overhead
a. pectoralis major
- action: 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
b. triceps brachii
- action: extends forearm at elbow joint and extends arm at shoulder joint
- innervation: radial nerve
- kicking a ball
a. gluteus maximus
- action: extends thigh at hip joint and laterally rotates thigh; helps lock in knee extension
- innervation: inferior gluteal nerve
b. biceps femoris
- action: flexes leg at knee joint and extends thigh at hip joint
- innervation: tibial and fibular nerves from sciatic nerve
- doing sit-ups
a. transversus abdominis
- action: compresses abdomen
- innervation: thoracic spinal nerves T8-T12, iliohypogastric nerve and ilioinguinal nerve
b. rectus abdominis
- action: flexes vertebral column, especially lumbar portion, and compresses abdomen; flexes pelvis on the vertebral column
- innervation: thoracic spinal nerves T7-T12
- breathing
a. diaphragm
- action: contraction flattens and increases vertical dimension of thoracic cavity resulting in inhalation; relaxation causes it to move superiorly and decreases vertical dimension of thoracic cavity resulting in exhalation.
- innervation: phrenic nerve from C3-C5
b. internal intercostals
- action: contraction draws adjacent ribs together to further decrease anteroposterior and lateral dimensions of thoracic cavity during forced exhilation
- innervation: thoracic spinal nerves T2-T12