Wheelchair cushions and operation

1. What is the benefit of having a smaller vs. a larger caster? What is the effect of a posterior caster?
2. What is the front rigging? How high above the floor should it be?
3. Why would an elevating legrest be used?
4. What are the six types of wheelchair cushions? What are the advantages and disadvantages of a Roho over a Jay cushion?
5. What is a grade aide?
6. What are four different control mechanisms for power WCs?

Answers:
1. Smaller casters have shorter turning radius but wobbles on uneven surfaces. A posterior caster decreases the turning radius, decreases stability, and increases maneuverability.
2. Front rigging refers to the footrest and legrest. It should have 2" of clearance above the floor.
3. An elevating legrest is used with decreasing dependent edema. It is used for BKA, knee extension contractures, and other joint abnormalities.
4. Contoured foam with gel insert (Jay), air-filled villous (Roho), gel-filled, coated contoured foam, foam, air-filled. A Roho provides the best pressure relief, but is high cost, less durable, and has poor seating stability.
5. A grade aide prevents the chair from rolling backwards and is helpful for patients with limited strength and endurance.
6. Joystick, head control (via headrest), chin control, sip and puff.