Front (Flexion/Pulling): Pectoralis Major: Pulls your arm across your chest (think "hugging"). Biceps Brachii: Bends your elbow (think "making a muscle"). Serratus Anterior: Lifts and rotates your shoulder blade upward. Rectus Abdominis: Tightens your core and helps you bend forward. Quadriceps Femoris: Straightens your knee (kicking a ball). Tibialis Anterior: Lifts your toes upwards and pulls your foot inward. Back (Extension/Pushing): Latissimus Dorsi: Pulls your arm down and back (think "pull-ups"). Triceps Brachii: Straightens your elbow (pushing something away). Gluteus Maximus: Extends your hip and helps rotate your leg outward (think "pushing off the ground"). Hamstring Group: Bends your knee and helps extend your hip (running). Gastrocnemius & Soleus: Raises your heel (standing on your tiptoes). Additional Muscles: Deltoid: Raises your arm to the side (think "shoulder press"). Erector Spinae: Supports and keeps your back straight. Sartorius: Helps bend your hip and rotate your leg inward (running). Brachioradialis: Assists biceps brachii in elbow flexion.