How do I determine the correct resistance for a Dynamic Rocker Back interface?

The DRBi includes a range of elastomers to change the resistance without having to order more equipment. The elastomers should allow the client to move the back and then assist the client back to an upright position. The least amount of resistance is the Yellow (soft) elastomer. The strength of the elastomer initially installed in a new DRBi is Clear (Medium). If the client is able to completely compress the clear (Medium) elastomer, then the Blue (Firm) should be evaluated. The next step is to evaluate the green (Extra Firm) elastomer.