How to Take Measurements for the Knee Brace Prototype

Here’s the photo guide to taking the measurements you will need.  There are seven altogether, four circumference and three vertical measurements.

This looks like a lengthy explanation, but the actual measuring should only take a few minutes at most.  Most of this is just clarification to try and head off common measurement mistakes.

Before you begin

Please use centimetres to ensure greater precision.  The numbers involved are quite small, so inches result in too much cumulative error. 

Kindly don’t change the number sequence or terminology of the measurements to avoid confusion.  Kitties are easily confused.

You’ll almost certainly want a helper to do the measuring so you can maintain normal posture during the process. 

You will also need either several elastics or pieces of string or shoelaces or something else you can tie around your leg to mark placement lines.  And a tape measure – not the crunchy kind from the hardware store, a soft bendy one intended for measuring people (you can get one from any craft or fabric store, or even most drugstores or a Walmart).

A note on measuring technique (if you’re a measurement novice)

If you’re new to measuring, do make sure your finger isn’t under the measuring tape when you take the reading.  It may sound funny, but inexperienced measurers do this sometimes, which really throws out the accuracy. 

Also, make sure you’re reading the correct point on the tape measure!  It sounds obvious, but with some tape measures, the way the numbers align with the notches can be very un-intuitive; we had a few issues with measurement errors during wrist braces testing due to this exact phenomenon.

Some tape measure markings really make it look like you should read the number behind, or in front of, the one you’re supposed to be reading, meaning it can significantly throw off the measurements.  Better be safe than sorry, so before you use any tape measure, lay it flat in front of you and study it to make sure you know which notch aligns with which number.

Marking the measurement areas

Position elastic bands or tie strings or shoelaces around the areas you will be measuring.  You can use a bit of tape to keep them in place if they tend to slide around on you.  These markers will help you visualize the placement of the future lace-up bands relative to your body, and help keep you consistent.

Note that the elastics or strings are going around the same areas as the lines you marked on your duct tape casting.  The measurements are going to serve as an accuracy check for the duct tape pattern.

If the elastics/strings just won’t stay put, you can always use a make-up pencil or water-soluble nontoxic marker to just draw the lines onto your skin.

Measuring the circumferences

Stand evenly with your weight distributed evenly on your legs, and make sure your helper holds the tape measure snugly around the body along the designated marker lines/elastics/strings, trying to keep it parallel to the floor.  There should be no gap at all between your skin and the tape, and there should be no sliding around.  But don’t pull so tight that you’re making dents in the skin either.

Take measurement (1) around where the top of the knee brace and the top edge of the upper lace-up band will go, (2) around the leg just above the kneecap, (3) around the top of the calf just under where the forward bump of the knee ends and things starts going in instead of out, and (4) around where you want the bottom of the brace and the bottom edge of the lower lace-up band to be. 

Please keep the numbering as given when you send your measurements.

Don’t measure while seated, because for some people, this significantly changes the girth of your leg muscles.

Taking the vertical measurements

With either a ruler or a tape measure, measure the following:

(5) the vertical distance between your top two elastics/strings (this will be the upper band width), (6) the vertical distance between the bottom two elastics/strings (this will be the lower band width), and (7) the vertical distance between the middle two elastics/strings (this represents the height taken up by your knee joint).  Again, please keep the numbering as given when you send your measurements.

Keep in mind that the lower/bottom lace-up band needs to be wide enough to hit the part where your calf begins to flare out, because that’s what’s going to be holding up the whole knee brace works.  On the other hand, you really shouldn’t make it so wide that it goes past the widest point of the calf, or it won’t do the job properly.

That’s it!  You’re done.

If you’re unsure of your technique, this might be a good time to quickly retake the seven measurements to make sure they’re coming out the same both times.  It won’t take long, and if you made a boo-boo, it’s better to find out now than after you end up with a knee brace that doesn’t fit!

A final reminder: please keep the numbering order when you send in your measurement form.  We’ve learned from past testers’ experience that getting the names or numbers of the measurements mixed up can wreak havoc on the fit of the final product.  Don’t take chances.