Wouldn’t it be great if we could have a look around inside the body to see what has gone wrong and fix it just like this kid’s picture of how muscles work.
 

The furnace in this picture could equate to the mitochondria or energy production centre in the cell.  This is where carnitine comes in.  Carnitine is like the man who opens the door to get the wood or coal into the fire to produce the energy for the rest of the muscle to work.  Then he opens it again afterwards to clear out the ashes and soot so the fire can burn better again.  This is more or less how carnitine works.

And there is more.  If we hop on board for a look see into other parts like painful muscles or joints we can see where the repair work needs to be and what is needed to come in to fix it.  Glucosamine is now a recognised aid to joint pain and your doctor may recommend it.  But there is much more.
 

If we use the knee in the picture opposite as an example of the joint, we can see there are a lot of different types of tissue.  A joint is where 2 or more bones meet and move against each other to allow an action.  In this case - the femur, tibia, fibula and the patella or knee cap.  There is muscle all around the bones and tendons attach the muscle to the bone on the other side of the joint to pull or relax.  There is fat cushioning the bone and muscle.  There is the meniscus or moon shaped cartilage (like the spring washer to tighten a bolt).  There is the articular cartilage at the end of the bone (the straight washer protecting the surface of the bolt), the synovial membrane enclosing the whole ‘joining’ unit and the synovial fluid which is like the grease for the bearings.  Painful bursa occur when fluid gets squashed or pinched or an irritation causes rub and inflammation. As well, inside this joint are mutiple ligaments holding the inside bones together.  If you have ever tried to cut the 2 bones of a roast joint apart, you’ll know how tough and intricate these ligaments really are.

 

This diagram shows some of the damage that can occur in a joint.  If your surgeon performs an arthroscopy, he is having a look inside with a very small camera attached to a TV monitor.  Circled are injuries like torn and damaged ligaments and cartilage There could be bone fragments floating loose, small breaks from stress fractures, osteoporotic bone or simply loss of the protective cartilage at the ends of bone, loss of lubricating fluid or damage and inflammation to the enclosing membranes.   Other potential injury sites are tight and torn muscles, which in turn can cause tight, torn or bruised swollen  tendons and so cause trapped nerves.