Muscle Functions and Actions

These flashcards cover key muscles of the upper back, shoulders, chest, abdomen, and legs, along with their primary actions.

Latissimus Dorsi

Extends, adducts, and medially rotates the humerus.

Quadratus Lumborum

Extends and laterally flexes the trunk.

Erector Spinae

Extends trunk when both sides contract; laterally flexes trunk when one side contracts.

Piriformis

Laterally rotates the leg.

Pectoralis Major

Flexes, adducts, and medially rotates the humerus.

Gluteus Maximus

Extends and laterally rotates the femur.

Levator Scapulae

Extends head, elevates, and retracts the scapula.

Gluteus Medius

Abducts and medially rotates the femur.

Tensor Fascia Latae

Flexes, abducts, and medially rotates the hip.

Iliopsoas

Hip flexor that also flexes the trunk.

Hamstrings

Flexes the leg at the knee and assists in hip extension.

Quadriceps

Extends the knee and flexes the hip.

Sartorius

Flexes knee and hip, laterally rotates the femur.

Gastrocnemius

Plantar flexion with the knee extended.

Soleus

Plantar flexion with the knee flexed.

Serratus Anterior

Protracts and stabilizes the scapula.

Rotator Cuff SITS

Group of muscles that laterally and medially rotate the arm and facilitate abduction.

External Intercostals

Lift the ribs.

Diaphragm

Lowers the base of the lungs during inhalation.

Rectus Abdominis

Flexes the trunk.

Transverse Abdominis

Compresses the abdomen.

Occipito-frontalis

Raises eyebrows, wrinkles forehead, and moves the scalp.