"In my twenties, while playing left back in soccer, I badly injured my left knee and could not walk properly for several months. In those days knee surgery was not the simple intervention that it is today. It was learning to function with a knee like mine which impressed upon me the urgency of doing something more. Our knowledge will undoubtedly improve in the future, but with good theory much of what we know now can be useful and applicable."
"I have discovered, through personal experience, a phenomenon which is now one of the foundations of my teaching. I believe that I have already mentioned that I badly injured a knee while playing soccer football in my younger years. It was a severe injury and I was incapacitated for many months. The healthy leg had to work overtime and lost much of its former flexibility and nimbleness. One day I slipped on an oily patch on the pavement while hopping on the only leg that functioned. I felt my knee nearly spraining but it finally slipped back into position. I hopped home. I then had to climb two flights of stairs and at the end of it was glad to lie down. Gradually I felt my good leg stiffen and thicken with synovial waters. My original injured knee was still strongly bandaged and sufficiently painful to prevent me standing on the foot. I hopped around, therefore, on the leg which I had nearly sprained, thinking that probably I would soon not be upright at all, and would have to stay in bed. I fell asleep with a heavy heart.
When I woke up and tried to see whether I could manage to reach the bathroom without help, I was surprised to find that I could actually stand on the foot which I had been unable to use since the original troubles. The trauma of the good knee had somehow made the injured leg more usable than before; in fact, had it been as good as it was then I would not have had to hop. I thought that I might be turning insane. How could a leg with a knee that had prevented me standing on it for several months suddenly become usable and nearly painless? This happened, moreover, when the quadriceps of the leg had nearly vanished, as is usual in severe injury of the meniscus, and the thigh was visibly thinner. It seemed to me that the vanished quadriceps had become suddenly toneful enough to allow me to stand on the foot. I had not heard of such a miraculous change in an injured knee when physical anatomical abnormalities were clearly to be seen on the X-ray pictures. Cold sweat covered my face and I did not know whether I was awake or dreaming. I held onto the furniture and tried to move. There was no doubt. I put my weight on the bad leg while the one on which I had been hopping became auxiliary. The old injured leg would not straighten completely, and I leaned on the toes rather than the heel, but there was no doubt that it supported the bulk of my weight.
For fear of ridicule I spoke to nobody, and remained unsure of what had happened. I was convinced there was something mentally wrong with me, as the healing of the knee in hours was unthinkable, and yet the mishap to the good knee had improved the sick one."
