Joseph Pilates originally began as a Self-Defense instructor at Scotland Yard, after moving to the UK from Germany. During the war, he was kept interned as an enemy-alien, and refined his training techniques, using spring resistance to help hospitalised patients. These later became a foundation of his equipment. He moved the New York and his training system became popular with the New York Ballet. It was not until after his death that his exercise system and equipment exploded into the popularity they enjoy today.
Stripped down to basics, Pilates involves slow, focussed movements designed to improve control of predominantly the spine and major large joints. The movements have an element of dynamic flexibility, and seem to be a combination of what physiotherapists would term “Core-Stability” exercise, balance, flexibility, and stabilisation of peripheral joints.
While a good Pilates session will work your body in incredibly diverse and interesting ways, it is not typically going to get you sweaty, puffing, or “feeling the burn”. It should be used as an addition to any complete fitness regime, coupled with traditional strength training, cardiovascular endurance, interval training, and great nutrition.
Ask your physiotherapist whether this sort of exercise may be of benefit for your condition or health plan.