CADS – Constant-Force Articulated Dynamic Struts The sport of skiing can create stress on our knees that can eventually lead to knee pain. The knee joint is controlled and supported by the large thigh muscle called the quadriceps. The quadriceps start above the hip and attach to the top of the shinbone via a tendon, which has the kneecap, or patella, built into it. When we “squat down” to compress into a ski turn, the quadriceps contract to prevent the leg from giving out. This force puts a lot of pressure on the bones of the knee, particularly the kneecap. If these bones are injured or damaged, there will often be pain. This kind of pain could be prevented and/or eased by developing strong thigh muscles, and by wearing a brace. Interestingly, when I was skiing in Colorado, I encountered another unique “knee saving” device called Constant-force Articulated Dynamic Struts, or CADS for short. The CADS device was developed by Vail-based engineer/inventor Walter Dandy as a suspension system to relieve knee pain. Each strut is a fiberglass rod, which is attached to the back of the ski boot, and runs up the back of the leg. A cable is anchored at the upper end to a pelvic harness and suspended over a pulley at the top of the rod. The bottom end of the cable attaches to a thick rubber band, fixed to the back of the ski boot. When the knee bends, the body weight loads onto the pelvic harness. The force is then transmitted via the cable and rod down the back of the leg to the elastic band. As the elastic band stretches, it unloads the thigh muscle at the front and takes stress off the knee. I heard about the CADS system when a friend with an injured knee asked me if I would go with him to try it out. I have to admit I was very skeptical. As the two of us were getting fitted with the device, it felt awkward, and to say the least, looked quite unusual. However I was able to get comfortable with it and was very impressed at how effective it was. Even though I don’t have knee problems, I could appreciate how much stress was taken off my quads. All sorts of skiers wearing CADS came up to chat with us and rave about the benefits. As a result of my experience, I have ordered a set of CADS to have here in Collingwood. I am convinced it will be a useful adjunct for many skiers with knee pain. It can also be helpful for skiers with other medical problems that weaken the thigh muscles, such as MS.