Jon, let me first of all congratulate you on creating a thread that is very interesting to me anyway.
I have been exposed to learning a few different energy healing systems, including Reiki, Tai Chi Qigong and some forms of Healing Qigong among others. A new system created by an Aikidoka and monk called Tao Shiatsu has recently perked my interest.
I think what you experienced was a basic example of energy healing, i.e. localised ki transfer to a specific area. Generally the body's entire physical, thought and energetic system is interlinked via the chakras and meridians that are used in acupuncture and practices of the sort. Detailed information about these linkages can be found in any good Shiatsu manual.
The heat you felt is the same as the heat that is generated whenever atoms are stimulated and begin rubbing together. The heat probably helped on a sensory level, but unless the person's hands generated the levels of heat found in your typical heat pack for a similar period of time that one would use a heat pack, the heat from his hands probably did not do the trick by itself.
It has been said that all matter, when broken down into its simplest form is pure energy (Einstein?????). If this is true then one should be able to affect matter for better or worse at a level of pure energy, right??
As far as heat and ki extension goes, I also saw the documentary that Anat alluded to earlier. In that same documentary, sound waves were detected to be leaving the Qigong master's hands at a rate of 6-8 hertz. These were detected by ULF microphones.
The fact is, we already use sound waves to generate heat... it's called a microwave
Funny how the same concept is met with question marks when people generate heat by projecting ki (a.k.a. light/sound vibrations???).
In the case of things like Reiki, this form of healing seems to be the most powerful from my experience, however, like the others, the success of the treatment is directly linked to the patient's knowledge of what is being done.
For all we know, when the person placed their palm on your knee, the most important healing element may have been telling you what he was doing. This could have triggered an entirely psychosomatic response to the injury.
I may have raised more questions than answers here, but this is just a sillhouette of my true feelings on the subject which will be too much to bore you with.
Peace to all.