Model how tendons, bones, and muscles work together to create movement! This engaging STEM project lets students build a working model of the human hand using foamboard, straws, and string. It’s perfect for units on anatomy, engineering, or simple machines—and makes a lasting visual aid.
Everything you need in one pack!
Perfect for: Homeschoolers or smaller classes.
Already have supplies? Just need the foam hand?
Only $2 — great for classroom, multiple classes or grade level
🖐️ Precut foam hand from ScienceWear
📄 Illustrated instructions (PDF available in Resources below)
🥤 Plastic straws (2 per hand) — Included in kit
🧵 String (4 meters per hand) — Included in kit
✏️ Pencil & fine black marker
🖍️ Map pencils or markers
✂️ Scissors
📏 Centimeter ruler
🔥 Hot glue gun & glue stick
💅 Optional: 5 artificial fingernails
a). Examine your foam hand and gently bend the fingers and thumb. The joints represent hinge joints that allow movement in one direction. Each finger has 3 joints, and the thumb has 2.
a). Draw the phalange, metacarpal, and carpal bones on the back side of the foam hand using a pencil. (Refer to image)
b). Color-code the bones with map pencils or markers.
c). Outline each bone with a black marker.
d). Mark the top of each distal phalange with a small black dot (both sides) — you’ll attach the string here later (10 total).
🧠 How Tendons Work
🖐️ The muscles that move your fingers are actually in your forearm, not in your hand.
🖐️ Tendons connect those muscles to your fingers.
🖐️ Tendon sheaths protect and guide the tendons as they move.
a). Prepare the tendon sheaths. Cut plastic straws into small pieces about 7–9 mm long. You’ll need about 19 pieces per side of the hand (back and palm).
b). Glue sheaths on the back of the hand. 🔥 Caution: The glue gun is hot! Be careful and ask for help if needed
> Glue one straw piece in the center of each intermediate and proximal phalange and each metacarpal bone.
> Glue five sheaths in a row across the bottom of the carpals (just above the wrist).
c). Repeat on the palm side.
> Flip the hand over and repeat the sheath placement on the palm side.
* You should have 19 sheaths total per side when finished.
💅 Optional: Glue on artificial fingernails for added realism.
Pull individual tendons and observe how the fingers bend. This simplified model shows how tendons move bones, but lacks muscle mass, soft tissue, and full anatomical shape. Ask students:
Key Concepts: Tendon function, joint structure, skeletal movement, engineering modeling, biomechanics.
