Measure from the most posterior point of the body to the inside of the knee, minus at least two inches. Optimal contact between the legs and the seat increases stability for the body.
Measured from the seat base to the top of the chair back. Sport users need enough height for upper body support, yet low enough to allow the arms and trunk to rotate freely.
Rear Seat to Floor3
Measurement from the ground to the rear seat edge. Relative to the front seat-to-floor dimension, this determines the rearward slope ("dump" or "squeeze") of the seat. Sport chairs usually have more dump for extra upper body stability.
Determines how far the toes extend away from the body, measured from the horizontal. Sport users often use very tight angles to be able to rotate in the smallest possible space.
Determined by the widest point of the body from knee to hip, plus an inch to ensure room to move. Sport chairs are typically as narrow as possible to save weight which improves agility.
Angle of the wheel relative to the vertical. More camber improves stability and agility, but also limits ability to pass through narrow spaces. A typical sport chair uses nine to twelve degrees of camber.
Front Seat to Floor7
Measure the leg from the back of the knee to the sole of the foot. Then subtract the thickness of the cushion when it is compressed. Next, add a minimum of two inches for footrest clearance. Do not add the footrest clearance if the chair will be foot-propelled.
Measure from the inside of each legrest tubing the distance or desired distance between legrests.
Center of Gravity9
Measure from the front of the seat back post to the center of the rear axel.
Seat to Footrest Length10
Measure from the edge of the seat upholstery to the top rear of the footrest.
Measure the the angle of the back post to the floor. Ninety degrees will be perpendicular to the floor, to approximate the angle from the back post to the seat, subtract two degrees from measurment for every .5" of dump.