Once you are out in the fitness world for a while, you will find that the sit and reach test is out of date. I recommmend that you look at ROM and movement in general as a joint specific and multi joint related aspect of fitness/health. And dynamic movement is far more important than simple ROM at any joint. How does the client move and what is happening at the feet, ankles, knees, hips, low back, thoracic spine, and shoulders during movement. I know you need to pass a test to get going. After that really get going and open your mind to the amazing ability of the human body.