A physical therapist is measuring a patient for a custom wheelchair. When measuring seat depth, the therapist measures from the most posterior aspect of the buttocks to the popliteal fossa and obtains 18 inches. What should the prescribed seat depth be?

A physical therapist is measuring a patient for a custom wheelchair. When measuring seat depth, the therapist measures from the most posterior aspect of the buttocks to the popliteal fossa and obtains 18 inches. What should the prescribed seat depth be?

• A. 18 inches
• B. 16 inches
• C. 20 inches
• D. 14 inches

Answer: (B)

When fitting a wheelchair, you measure seat depth from the most posterior aspect of the buttocks to the popliteal fossa, then subtract about 2 inches to allow for clearance behind the knee and to prevent pressure at the popliteal area. In this case the measurement is 18 inches, so subtracting 2 inches gives a prescribed seat depth of 16 inches. A seat depth of 18 inches would place the edge at the popliteal fossa and could cause pressure and circulation issues; 20 inches would be too deep, risking poor posture and difficulty with propulsion; 14 inches would be too short, reducing thigh support and increasing edge pressure.

When fitting a wheelchair, you measure seat depth from the most posterior aspect of the buttocks to the popliteal fossa, then subtract about 2 inches to allow for clearance behind the knee and to prevent pressure at the popliteal area. In this case the measurement is 18 inches, so subtracting 2 inches gives a prescribed seat depth of 16 inches. A seat depth of 18 inches would place the edge at the popliteal fossa and could cause pressure and circulation issues; 20 inches would be too deep, risking poor posture and difficulty with propulsion; 14 inches would be too short, reducing thigh support and increasing edge pressure.