Much of the time I counsel people I see in the clinic that “It won’t get better if you don’t stop hurting it”. There are a few significant situations when I don’t say this. The most important instance when resting the part does not make it better is with osteoarthritis, or OA as is commonly abbreviated.
OA can occur after an injury to a joint that involves the articular cartilage, the covering directly on the bone ends within the joint. When this happens, some of the cartilage can be destroyed and will not regenerate.
However, the most common reason for OA is advancing age, wear and tear arthritis. It seems to also have an inherited factor in some cases, making some people more susceptible than others, and causing various degrees of severity. But, in all cases of OA, if the person having the joint pain avoids moving because of the pain, the arthritis gets worse. Seems counterintuitive, but it’s true.
The reason this seeming mystery of holding still making joint pain worse is revealed when we examine how joint cartilage receives nutrition. You see, joint cartilage has no blood vessels in it, so has no circulation to bring nutrition to the living cells of the cartilage, or to take away waste products of cell activity. The only way the cells receive nutrition is through the absorption of some of the synovial fluid, the liquid that bathes the joint surfaces and helps the sliding of one bone on the other by lowering friction. It actually is one of the slipperiest fluids known. How does it get into the cells? By the movement of the joint, causing alternating compression and relaxation of the surfaces together then back apart. When the pressure on the surfaces is released, the decreased pressure allows the liquid to enter the cells carrying the nutrition in. Then, pressure on the cells, when the bones come back together squeezes the liquid and waste products out, and the cycle is repeated. The important constant that makes this system work is movement of the joint. When the person with OA sits down, decreasing moving because the pain of movement is bothersome, the lack of movement starves the remaining cartilage cells of nutrition, and they start to suffer as a result. The result is the rate of decline increases. In some cases, the resting position places constant pressure on the bone ends, also resulting in starving of the cells.
Does this mean that the OA sufferer must “push through the pain”? Yes and no. Yes, the person must keep the joint moving, but no the person does not need to try to do the moving in exactly the same fashion as in the good ole days. Modification to decrease the pain consequence is an option in order to keep moving. Perhaps stationary bicycle or even push bike, rather than walking or jogging is an idea for bad knees. The bicycle seat takes the body weight but the knees still get to move. My favourite that I always remind people of is the swimming pool, where gravity reduced motion is easiest. Most people don’t take me up on that option just because they don’t like to swim, can’t get there, or whatever, but it remains one of the best solutions to keep moving while taking away some of the stress of movement. In this case, the pool efficiently does it for many joints in the body, not just knees.
These comments are general in nature. Be sure to check with your physio or doctor if you are not sure whether they apply to your situation.
