Mechanical Station LAB 2.1:
Mechanical Systems in Health Fields

Measuring Range of Motion
Understanding Your Joints and Movement

https://www.flickr.com/photos/bernhard_ungerer/2598558747/in/photostream/

• Lab Goal: The goal of this lab is to measure the range of motion for one example of each type of joint discussed, using models of the skeleton.
• Materials Required: Protractor, pencil, answer sheet and joint models (all provided)
• Objectives for Experiment:
  • Correctly identify joints in your body as one of the synovial joints listed below. In addition to the examples listed, try to come up with one more of each type. (Remember, some joints may be a type that we will not discuss!)
  • Use the protractor and joint models to accurately measure the range of motion for one example of each type of joint discussed.
  • Correctly define the terms in bold from the introduction related to the types of joints listed and how they move.
  • List injuries that could result from going outside of the set range of motion for a joint.
• Prerequisite knowledge: 6th-8th grade reading level. All instructions are provided.
  
• Applied Health Terminology:  Like many professions, the medical field has its own vocabulary. We have created flashcards to help you learn some of the vocabulary related to joints and movement that was used in this lesson.

You can find these flashcards on the computer at the site below.

Instructions to site:

1. Click on the link below.
   https://quizlet.com/84080755/mechanical-station-31-range-of-motion-flash-cards/
2. Then click on the “Flashcards” button in the upper left corner of the screen.
3. For each card, say the word out loud and try to say what you think the definition is.
4. Flip the card by clicking on it and say the definition listed out loud.

• Evaluation: Your lab performance will be evaluated by the criteria (standards) you will find in this project’s rubric. A rubric is simply a table that states how you will be evaluated. Your coach will use this table to report your performance.
• Process summary: At this station you will..
  • Review the medical vocabulary and read instructions on how to measure the range of angles for three different types of joints.
  • Practice measuring angles of joints on skeletal joint models.
  • Be instructed on how to use the protractor to measure angles of each joint.
  • Identify the range of motion for each joint that you measure.
  • Identify one more example of each type of joint discussed, other than the ones you will measure.
  • Identify injuries that may occur due to going outside of a joint’s safe range of motion.

CLICK HERE TO GO TO THE RUBRIC

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INTRODUCTION

How do different joints allow you to move?

Interesting Facts to Know

Our Bones and Joints

Bones are firm and keep you from dropping like a blob of flesh on the floor!

If our bodies only had one big bone, how would we pick things up, bend over or even walk? Our bodies have many bones so that we have a lot of movement. Bones meet at joints. A joint is where two bones come together. The joints most people think of are the ones that allow movement between two different bones (there are some joints that are locked in one position).

How far can a joint move? It depends on the joint. The entire set of different positions that we can make between two bones (for example, using your elbow to bend your arm) is called the range of motion for that joint.

Degrees in Range of Motion

Each position that you can make with a single joint has an angle that we can measure. An angle is a measurement between two lines that start at the same point, using what are called degrees.

When you write a number that shows a degree, that number is always followed by a degree symbol. It looks like a little zero after the number, as you see in the image below.

All angles are related to parts of a circle. A full circle is always 360 degrees (or 360°).

If you start at the top and go around the whole circle, this is a total of 360°. Each quarter (1/4) of the circle (each pie piece shown above) is equal to 90°.

http://www.mathblaster.com/coolmath/articles/angles

Any angle that is 90° is called a right angle, and is always drawn with a little square inside of the angle.

 

 

 

http://cerro.slocoe.org/DigitalMath/glossary/acute_angle.html

An angle that is less than 90° is called an acute (uh-CUTE) angle. Any angle from 1° to 89° is acute. Do you think that acute angles are cute?

 

 

 

http://cerro.slocoe.org/DigitalMath/glossary/acute_angle.html

An angle that is more than 90° but less than 180° is called an obtuse (awb-TOOS) angle. Any angle from 91° to 179° is obtuse.

 

http://commons.wikimedia.org/wiki/File:180-Degree_Rotation_2.png

A straight line is equal to 180°, or half of a circle.

Look at the images below and identify the angles shown as right, acute, obtuse, or straight. Some of the angels are highlighted in yellow for you. How many more can you identify? Check the definitions above until you are sure.

 

To understand the movement of joints, you will also need to understand directions of motion. The body is three-dimensional (3D) and so it has three different axes (AKS-ees) or directions, which are labeled with the letters x, y and z:

Image modified from http://commons.wikimedia.org/wiki/File:Human_body_front_and_side.svg

Each axis represents one dimension (or pair of directions), and the area outlined by two axes is called a plane, a two-dimensional (or flat) area. The body also has three planes:

(Images below from http://what-when-how.com/nursing/organization-of-the-human-structure-and-function-nursing-part-1)

The first is called the frontal or coronal (core-OWN-uhl) plane. This is the area between the z-axis (up and down) and the y-axis (left and right). This plane splits the body into front and back halves. Movement along this plane would be like putting your arm straight out at your side, and then lowering it to hang at your side.

The second is called the sagittal (SAJ-it-uhl) plane. This is the area between the z-axis (up and down) and the x-axis (forward and back). This plane splits the body into left and right halves. Movement along this plane would be like putting your arm straight out in front of you, and then lowering it to your side.

The third is called the transverse plane. This is the area between the y-axis (left and right) and the x-axis (forward and back). This plane splits the body into top and bottom halves. Movement along this plane would be like holding your arm straight out at your side, then swinging forward so it is straight out in front of you.

Every joint in your body has a specific range of motion. That means that it has a minimum and maximum angle that can be made with the bones of that joint.

There are actually several types of joints. Some do not even allow very much movement! The ones we will focus on in this lab are called synovial (sin-O-vee-uhl) joints. Synovial joints have a fluid-filled sac around them to allow gentle free movement between bones.

Synovial Joints

There are six types of synovial joints. Here we will only focus on the three that you are probably most familiar with.

The Hinge Joint

The first type of synovial joint is called a hinge joint. An example of a hinge joint would be your elbow. Hinge joints work similar to a hinge on a door, and only allow movement in one direction. For example, if you lay your arm with your elbow on a table, you can bend your lower arm up toward your face, but you cannot bend it side to side (unless you want to hurt yourself!)  This type of joint only moves in one plane. A plane is a flat area going in directions like up and down only or side to side only). Can you guess the range of angles that a hinge joint allows?

The Pivot Joint

The next type of synovial joint is called a pivot joint. An example of a pivot joint would be your neck, which allows you to look from left to right. (A different joint allows you to move your head up and down is a different joint.) You will notice though, that pivot joints only allow limited rotation (like moving your head side to side) around a center point or axis (your spine). When you move your head to the left, you hit a place where you cannot turn your head anymore, and the same happens as you turn your head to the right. Can you guess the range of angles that a pivot joint allows?

The Ball-and-Socket Joint           Joint images from http://en.wikipedia.org/wiki/Synovial_joint

The last type of synovial joint we will talk about is called a ball-and-socket joint. It is called this because this type of joint has one bone that is shaped a lot like a ball, which fits into another cup-like bone called the socket. An example of a ball-and-socket joint would be your hip, which allows your leg to move in many ways. Ball-and-socket joints have the greatest range of motion because they allow movement in all directions. How many directions can you move your leg? Can you guess the range of angles that a ball-and-socket joint allows?

Process Summary:  In this Lab you will:

• Correctly identify joints in your body as one of the synovial joints listed below. In addition to the examples listed, try to come up with one more of each type. (Remember, some joints may be a type that we will not discuss!)
• Use the protractor and joint models to accurately measure the range of motion for one example of each type of joint discussed.
• Correctly define the terms in bold from the introduction related to the types of joints listed and how they move.
• List injuries that could result from going outside of the set range of motion for a joint.

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Links to Station 2.1 Modules
Lab Intro | Lab Presentation and Practice | Communications Intro| Communications Presentation and Practice| Math

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