Turning a door knob
Muscle: Pronator quadratus
Action: Pronates forearm at radioulnar joints.
Innervation: Median nerve
Muscle: Brachioradialis
Action: Flexes forearm at elbow joint; supinates and pronates forearm at radioulnar joints to a neutral position
Innervation: Radial nerve
Muscle: Supinator
Action: Supinates forearm at radioulnar joints.
Innervation: Deep radial nerve
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: Latissimus dorsi
Action: Extends, adducts, and medially rotates arm at shoulder joint; draws arm inferiorly and posteriorly. RMA: Elevates vertebral column and torso.
Innervation: Thoracodorsal nerve
Muscle: Teres minor
Action: Laterally rotates and extends arm at shoulder joint.
Innervation: Axillary nerve
Kicking a ball
Muscle: Gluteus Maximus
Action: Extends thigh at hip joint and laterally rotates thigh; helps lock knee in extension. RMA: Extends torso.
Innervation: Inferior gluteal nerve
Muscle: Gluteus medius
Action: Abducts thigh at hip joint and medially rotates thigh. RMA: Elevates vertebral column and torso.
Innervation: Superior gluteal nerve
Muscle: Quadriceps
Action: Extends leg at knee joint
Innervation: Femoral nerve
Doing sit-ups
Muscle: 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
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: Psoas major
Action: Psoas major and iliacus muscles acting together flex thigh at hip joint, rotate thigh laterally, and flex trunk on hip as in sitting up from supine position.
Innervation: Lumbar spinal nerves L2–L3
Walking
Muscle: Gluteus minimus
Action: Abducts thigh at hip joint and medially rotates thigh. RMA: Elevates vertebral column and torso.
Innervation: Superior gluteal nerve
Muscle: Gluteus Maximus
Action: Extends thigh at hip joint and laterally rotates thigh; helps lock knee in extension. RMA: Extends torso.
Innervation: Inferior gluteal nerve
Muscle: Quadriceps
Action: Extends leg at knee joint
Innervation: Femoral nerve
Breathing
Muscle: Diaphragm
Action: Contraction causes it to flatten and increases vertical dimension of thoracic cavity, resulting in inhalation; relaxation of 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)
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: Sternocleidomastoid
Action: Flex cervical portion of vertebral column, extend head at atlanto-occipital joints; laterally flex neck and head to same side and rotate head to side opposite contracting muscle. Laterally rotate and flex head to opposite side of contracting muscle.
Innervation: Accessory (XI) nerve, C2, and C3