Crutches are a walking aide made of wood or metal. This type of assistive device requires upper arm strength, coordination and balance. Crutches that are too tall or too short can affect your balance and also cause back pain. Incorrectly fitted crutches or poor posture can cause a disorder called crutch palsy in which the nerves under the arm are temporarily or permanently damaged, causing weakened hand, wrist and forearm muscles. Two types of crutches are underarm crutches and forearm crutches. Correct measurements can minimise complications and promote safe use of the crutches. To ensure correct measurements, it is easier if someone else measures you.
Underarm crutch measurements
Place the person's regular walking shoes on his feet.
Assist the person to a standing position. If the person is too weak or unsteady to stand, instruct them to lie on her back.
Measure from the fold under the person's arm to a spot on the floor that is approximately 5 cm (2 inches) ahead and 15 cm (6 inches) to the side of his foot if the person is standing up. If the person is lying down, measure from the front of the underarm fold to the heel and subtract 5 cm (2 inches).
Select a pair of crutches based on the person's measurements.
Adjust the hand grips up or down so the person is able to bend his elbow approximately 15 to 30 degrees.
Check the final fit of the crutches. The top of each crutch should be about two finger widths from the underarm and his wrists should be even with the hand grips when his arms hang at his side.
Forearm crutch measurements
Place the person's regular walking shoes on his feet and assist him to a standing position.
Instruct the person to flex his elbow so the crease of his wrist is level with his hip joint.
Measure the forearm from 8 cm (3 inches) below the elbow and then add the distance between the wrist and floor.
Measure around the largest part of your forearm for the cuff size.
Select a pair of crutches based on the person's measurements. Adjust the length of the crutches up or down to match the measurements.
Wood crutches are adjusted by moving the wing nuts and metal screws to the appropriate holes in the bottom of the crutch. Metal crutches are adjusted by pressing the button at the bottom and telescoping them up or down. Don't use the metal crutches until the button snaps back through the appropriate hole.