• Rectus Abdominus

  • Located: Anterior trunk (like the top layer of a cake). 🎂
  • Special feature: Gives the iconic “six-pack” look. 💪
  • Function: Helps pull the trunk forwards. Imagine doing an ab crunch!
  • Real-life example: Think of the movement a gymnast makes when doing a sit-up during their routine.

• External Obliques

  • Located: Front/side of the trunk, under the Rectus Abdominus.
  • Originates: Lower eight ribs. Ends at the ilium.
  • Function: Sideways bending and rotation.
  • Real-life example: Picture a salsa dancer moving their hips side to side. 💃

• Erector Spinae

  • Located: Alongside the spine.
  • Origin: Different starting points on the vertebrae.
  • Function: Helps pull the trunk backward (extension). Think of leaning backward to look at the sky!
  • Real-life example: When you're stretching backward after sitting for too long at your desk.

• Deltoid

  • Located: Around the shoulder.
  • Origin: Scapula and clavicle.
  • Function: Most shoulder movements.
  • Real-life example: When you're reaching out to grab a high shelf item at a grocery store.

• Pectoralis Major

  • Located: Entire anterior chest.
  • Origin: Clavicle, sternum, and anterior ribs.
  • Function: Any arm movements going forward or up.
  • Real-life example: Think of a basketball player shooting a hoop. 🏀

• Biceps Brachii

  • Fun fact: Has two heads, hence "bi".
  • Origin: Scapula.
  • Function: Brings arm up at the shoulder and bends the elbow.
  • Real-life example: Flexing to show your muscles!

• Trapezius

  • Located: Posterior neck and upper back.
  • Shape: Like a triangle 📐.
  • Function: Raises shoulders and controls scapula movement.
  • Real-life example: Shrugging when you don't know the answer in class.

• Latissimus Dorsi

  • Located: Large back muscle.
  • Function: Brings arm backward and rotates it inward.
  • Real-life example: A rower pulling their oar or a swimmer doing a stroke. 🚣‍♀️🏊

• Triceps Brachii

  • Fun fact: Has three heads, hence "tri".
  • Located: Posterior upper arm.
  • Function: Moves arm backward at the shoulder and straightens the elbow.
  • Real-life example: Think of pushing open a heavy door.

🌍 Takeaways

• Our muscles are incredibly versatile, allowing us to do various activities from dancing to swimming.
• Trunk muscles = core strength. Upper extremity muscles = power in our arms and shoulders.
• Keep these functions in mind, and next time you're playing a sport or just dancing in your room, you'll know which muscles you're working out! 💃🕺