How to Take Accurate Measurements for a Seating Matters Chair

How to Take Accurate Measurements for a Seating Matters Clinical Chair

By Martina Tierney, OT

After determining that a Seating Matters chair is right for you or your client, it’s time to take measurements.

Accuracy at this stage is critical.

Correct measurements will ensure that you are getting the right chair; a chair that is comfortable and caters to your client’s pressure management and support needs.

A chair that is too tight around the body may cause friction.

A chair that is too big may not provide proper pressure management, or could allow for too much bodily rotation.

As every Seating Matters chair is custom designed to suit the patient’s individual dimensions and clinical needs, it is important that we get the correct measurements before making your chair.

Need a helping hand? Our trained Seating Specialists across Australia are available to conduct individual Seating Assessments, which include taking accurate patient measurements, and offer chair trials. All assessments are complimentary, with no obligations to hire or purchase a chair.

For those who live in areas not serviced by a local Seating Specialist (or for anyone who prefers to DIY), keep reading for some simple steps and tips on how to collect accurate patient measurements.

General Tips: How To Measure for a Therapeutic Chair

  • Two people are needed to measure someone correctly
  • The person being measured must be seated
  • Use a measuring tape and make sure to write down the dimensions clearly
  • Account for bulky or layered clothing
  • The measuring tape should be laid flat, rather than wrapped around the
    person’s body
  • Note any bodily rotation in the trunk and/or lower extremities while seated

To Measure Seat Width:

Seat width measures the seat in order to determine cushion size, as well as the distance between each arm.

When measuring seat width, consider which part of the patient’s seat is the widest apart. Is this the hips, or the knees?

If the hips are widest, place a flat hand on each hip and, with a measuring tape, measure the length from the outside edge of each hand.

If the patient’s hips are abduct, their knees will likely be the widest distance apart. In this case, you need to measure from the outer edge of each knee. Note: whether or not the patient’s knees are “windswept” to one side, they may require additional accessories to support or correct this.

To Measure Seat Depth:

Seat depth determines how long the patient’s seat will be. It is the length from the back of the buttocks to behind the knee.

To measure seat depth, place one hand on the back of the person being measured. With your other hand, place two fingers behind the patient’s knee.

Measure from the palm of your hand to the edge of your closest finger, leaving about 1 inch of space to the patient’s knee.


To Measure Seat Height:

Seat height measures the seat to floor (or footplate) length. It is measured from behind the
patient’s knee to the sole of their foot, while seated. 

It is very important to measure seat height correctly as up to 19% of someone’s weight is distributed through their feet while sitting.  

Make sure that you measure both legs, as some people’s legs can be different lengths or have different support needs.

To Measure Back Height:

Back height determines the  length from the top of a person’s head to seat.

To measure back height, first ensure that the person’s body is fully loaded in their chair. You can then measure from the top of the person’s head, to the top of the cushion seat.

To Measure Arm Rest Height:

Arm rest height will determine where the arms rest.

It is essential to ensure that this measurement is correct as arm rests support good posture.

Make sure the shoulder is supported, but not too unnaturally high.

Hold the person’s arm at a 90-degree angle as if resting on an armrest. Measure from just below the arm to the top of the seat cushion.

Consider Back Angle Requirements:

You may need to accommodate client needs by opening the back angle on your chair.

As a general rule of thumb, the hip angle should match the angle of the back of the chair.

Need a visual? In the below video, I outline the measurements we require to correctly fit a patient to a chair, and how to best measure them.

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