High Five: Investigating Hand Muscles!

Objectives

  • Make a muscular hand model
  • Understand how the body’s musculoskeletal system helps people move

What Do I Do All Day?

Hi! I’m a Orthopedic Specialist – did you know that our bodies are able to move because of our muscles and joints? I am an expert on the musculoskeletal system – that is a fancy way of saying I know all about our bones, joints, and muscles that help us move! Sometimes our bodies hurt when we bend our knees or hips, and that’s when you see me. I can help your body heal so it doesn’t hurt anymore! I can even help your body heal broken bones! (Left: Dr. Ayesha Abdeen is a board-certified orthopedic surgeon who specializes in hip and knee joint replacement at Beth Israel Hospital in Boston, MA)

Materials Needed

  • Card stock or cardboard (note: must be heavier than regular construction paper)
  • String or yarn (cut into approx. 10-15’’ lengths)
  • Re-usable straws (cut into approx. 1’’ and 3-5’’ lengths)
  • Tape
  • Scissors
  • Writing utensil (pencil, pen, crayon, etc.)

Background

  1. Bones give humans their structure and shape and protect our vital organs.
  2. Bones are made up of calcium, phosphorus, sodium and other minerals, as well as collagen
  3. With tendons, ligaments and muscles, bones allow us to move.
  4. The human backbone – also known as the spine – is a series of bones that stretches all the way from the neck to the pelvis/hips
  5. The spine is made up of 33 smaller bones called vertebrae that connect up kind of like puzzle pieces, but can move around and twist
    1. Vertebrae have a main body, an opening in the middle, and spiny parts called processes where things attach to them
  6. The musculoskeletal system is what helps make our bodies move; it is comprised of ligaments, bones, muscles, tendons, joints, and other connective tissues.
  7. There are more than 600 muscles in your body. The largest muscle in your body is gluteus maximus – a muscle located at the back of your hips (also known as the butt).
  8. Skeletal muscles are attached to the skeleton and facilitate movement. Skeletal muscles can only move in one direction, so they work in pairs. Our brains send signals to our muscles to let them know they should move.
  9. To keep your muscles healthy and strong, you must eat a healthy diet with lots of protein as well as exercise.
  10. Types of Muscle Tissue
    1. Muscles can be striated – striped with muscle units – or smooth.
      1. Striated muscles – also known as skeletal muscles – controls your skeletal movements.
      2. Smooth muscles – also known as non-striated muscles – help with movements in the stomach, intestines, and blood vessels. Fun fact: When your hair stands up on your arms, those are your smooth muscles at work!
    2. Cardiac muscles are only found within your heart and help your heartbeat. Can you feel your cardiac muscles at work?

Activity Plan

  1. Connect to prior knowledge:
    • Ask: What parts of our bodies make it so we can move?
    • Explain: Our bodies move because of our musculoskeletal systems. The musculoskeletal system is made up of our bones, tendons, ligaments, joints, muscles, and other connective tissue!
    • Ask: Can you move your hands/musculoskeletal system?
    • Explain: Today, we will be creating a model of a hand and musculoskeletal system that can actually move like our hands!
  2. Place your hand on the cardboard/paper and use a writing utensil to trace around your hand. Cut out the tracing of your hand.
  3. Select 14 1’’ straws (three for each finger and two for the thumb) and five 3-5’’ straws (for the palm and wrist).
  4. Line up three 1’’ straw segments on each finger. Line up two 1’’ straw segments on the thumb. Place five 3-5’’ straw segments along the hand and wrist; they should be in line with the thumb and each finger. Tape the straw segments down to secure them to the cut-out hand.
    • Note: Do not cover the ends of the straw segments.
  5. Tape five pieces of 10-15’’ string to the back of the hand, then thread the string through each finger and thumb’s straws all the way down to the wrist. Your hand should look like the below image.
  6. Encourage the group to pull the strings.
    1. Can you make the thumb and fingers move at the same time?
    2. Can you isolate the movement of a single finger/thumb?
    3. Can you isolate the movement of a single finger/thumb segment?
    4. Can you make a secret handshake with a partner?