Overview of Goniometer
A goniometer is a tool used to measure the angle of an object or to allow the object to turn to a specific position. In the field of bone healthcare (orthopedics), this tool is mainly used for measuring. The process of using a goniometer to measure the range of motion at each joint is known as goniometry.
The term ‘goniometry’ comes from two Greek words: ‘gonia’, meaning angle, and ‘metron’, meaning to measure. The earliest known form of the goniometer that we use today was developed by a Dutch doctor and mathematician, Gemma Frisius. He used this device to figure out the position of stars and planets in relation to the earth.
Anatomy and Physiology of Goniometer
The range of motion is a term used to describe the movement around a specific joint or part of the body. This is often measured by doctors, physical therapists, and other health professionals with the help of a tool called a goniometer. The goniometer measures the angles of movement at a joint. There are three types of range of motion, each used for a different purpose: passive (done by someone else), active (done by the patient themselves), and active assistive (done by the patient with some help).
There are several types of goniometers:
Universal goniometers: These come in two versions. The short-arm version is typically used for smaller joints, like the wrist, elbow, or ankle. The long-arm version is used for larger joints, like the knee and hip. This is the most commonly used type of goniometer.
Twin axis electrogoniometer: This type of goniometer is very reliable but may be a bit tricky to use during patient evaluations. Because of this, it’s commonly used for research purposes.
Gravity goniometer/inclinometer: This version of a goniometer has one arm with a weight that always points straight down due to gravity.
Software/smartphone-based goniometer: This is a type of goniometer that can be used on a smartphone. It’s easily accessible, can track measurements through certain apps, and only requires one hand to use. The phone’s built-in sensors calculate joint angles.
Arthrodial goniometer: This version is especially helpful in measuring movement and angles in the neck area.
Why do People Need Goniometer
A goniometer is a tool that is used in many different ways. Here’s how doctors typically use it:
1. To check if there’s a problem with your muscles, tendons, or joints.
2. To help figure out what kind of disease or health problem you have.
3. To set treatment goals. This means deciding what the outcome of the treatment should be.
4. To track how well the treatment is working, or if it’s not improving your condition.
5. To adjust or change the treatment based on how well it’s working.
6. To help make orthoses, which are devices that can help support your muscles or joints.
7. To take measurements in support of scientific research.
When a Person Should Avoid Goniometer
There are certain situations where a tool called a goniometer, which is used to measure how much you can move your joints, should not be used. These include:
1. If a joint has been dislocated, which means the bones that form the joint have been pushed out of place.
2. If there’s a fracture, or broken bone, that hasn’t healed yet.
3. After surgery, if moving the joint would interfere with healing.
4. For parts of the body with osteoporosis or fragile bones, as forced measurements could potentially cause further damage.
5. If moving the joint could potentially cause damage to the soft tissues around it after an injury.
However, there are some situations where a goniometer can be used, but with extra caution, such as:
1. If there is an infection or swelling around a joint.
2. If severe pain is made worse by movement.
3. If the joint is excessively mobile or not stable.
Equipment used for Goniometer
A goniometer, much like a complex protractor, is made up of three key parts:
1. The Body: This works like a protractor you might remember from math class and can be shaped like a full or half-circle. It shows a scale that measures the range of the joint’s movement in degrees. A half-circle model measures from 0 to 180 degrees, while a full-circle covers 0 to 360 degrees. The scale has small marks that show the degrees and these can range from 1 to 10 degrees.
2. The Fulcrum: The fulcrum is similar to a screw found in the center of the goniometer. It lets the moving part of the device twist and turn easily within the main body. The screw can be adjusted: tightened to fix the moving arm or loosened so it can move freely. Both the fulcrum and the main body of the device are placed over the joint being evaluated.
3. The Arm: There are two arms of the goniometer – the stationary arm and the moving arm. The stationary arm aligns with the stable part of your joint. This arm is attached to the goniometer’s body and can’t move on its own. In contrast, the moving arm aligns with the part of your joint that moves.
There’s also another method to measure joint movement using devices called an accelerometer and a rate gyroscope; both of these use a technology named a microelectromechanical system.
Who is needed to perform Goniometer?
The use of a tool called a goniometer, which measures range of movement in a joint, should be done by healthcare professionals like doctors or physical therapists. They have had special training on how to use this tool correctly. These experts need to know several steps to use the goniometer effectively:
1. They need to position and secure the joint correctly before taking a measurement.
2. They must be able to move the body part in a way that covers all the movement it’s capable of.
3. They need to know when the joint has moved as far as it can and how it feels at that point.
4. They should be able to feel the right bony markers, which are specific areas on the body that need to be measured.
5. They must correctly align the goniometer with these bony markers.
6. They have to read the tool correctly to get accurate results.
7. Finally, they need to write down the results correctly, so they can be referred to in the future, if necessary.
Preparing for Goniometer
Using a goniometer, a device to measure angles of the joints, is quite straightforward and doesn’t need any complex preparations. However, the patient should be informed and agree to the examination ahead of time. It’s important to have good lighting during the test, and the area around the joint that’s being checked should be clearly visible. If help is necessary, an assistant should be available ahead of time.
How is Goniometer performed
A goniometer is a tool used to measure the range of motion in your joints, both when you move them yourself (active) and when someone else moves them for you (passive). The way you are positioned is crucial in this process, as it sets the starting point for the measurement and ensures the right part of the joint is stable.
Here’s how a typical measurement process works: The examiner will hold the joint in place and gently move it through its full range of motion until it can’t go any further. Then, they perform these steps:
- Bring the joint back to the starting position, locate the important points on the bone, and align the goniometer.
- Record the starting measurement, remove the goniometer, and let the patient move the joint as far as they can.
- Put the goniometer back and align it with the points on the bone. Read and note down the measurement.
The examiner will do this three times and work out the average to get the measure of active range of motion. If both sides of the body have the same joint (like a knee or elbow), they will compare the results. The examiner will also determine the passive range of motion, where they move the joint for the patient, and repeat these steps. The patient needs to stay still during this entire process to make sure the measurements are correct.
Your position also affects the level of tension in soft tissues, like the capsules, muscles, and ligaments that surround a joint. Certain positions that tighten these structures will limit range of motion compared to positions where they are relaxed.
To get consistent results, the examiner needs to test the joint in the same position each time. This ensures the tension in soft tissues remains constant in each test. Any changes in position could lead to inaccurate results.
The normal range of motion varies between individuals, and can depend on factors such as your age and the specific joint being measured.
Possible Complications of Goniometer
Problems associated with goniometry, a technique used to measure joint angles, are few and mainly due to incorrect methods. Here are some of these problems:
1. If the technique used is not accurate, it can lead to incorrect measurements which can greatly influence a patient’s treatment. This is because goniometry is used to assess a patient’s physical progress and help plan their therapy.
2. If the person doing the goniometry pushes too hard when trying to measure the range of motion of a joint, it can accidentally hurt patients, especially those who have weak, fragile bones (a condition known as osteoporosis).
What Else Should I Know About Goniometer?
A goniometer is a device that doctors use to measure the range of movement in your joints. It can be helpful in many situations, such as measuring the flexibility of the spine in patients with a condition called ankylosing spondylitis or checking how much the spine can move after surgeries for a condition called scoliosis. The goniometer can also show improvements in the movement range of joints in the arms and legs.
However, there isn’t complete agreement among medical professionals on whether or not the goniometer is always effective enough to tell if a treatment is working. The type of goniometer used might also influence the reliability of the results. In some cases, the measurements from the goniometer may not show a significant change, even when there might be one.
