Re: muso shinden ryu
Assuming the ache is indeed osteoarthritis ("wear and tear" of the cartilage at the end of the femur), then yes glucosamine/chondroiten in sufficient doses (IIRC at least 1200 mg/day glucosamine in divided doses) has been shown in clinical trials for pain of osteo of the knees to be as effective as non-steroidal antiinflammatories for many people. Niamh is correct, it can take weeks to tell if it will help. If it does, you need to then just keep taking it.
Ibuprofen or other nonsteroidal antiinflammatories can be used at the same time as glucosamine; they work totally differently.
Ice/cold is very specific for acute injury/swelling. If you are not having that kind of acute flare up, try both cold and heat, as there is no evidence one is more effective then the other. Some folks seem to do best alternating them (5 minutes cold, 5 minutes hot). Others find for chronic aches, esp osteoarthritis, nothing beats heat.
Topical irritants ("warmers" like BenGay, TIger Balm, Jointritis, etc) with capsicum, menthol or salicylic acid are considered safe for use in chronic arthritis also. They seem to affect the sensory nerves, blocking the pain sensation. A tiny percentage of folks don't tolerate the effect on the skin, so if you're trying for first time, apply it at home near a sink and washcloth!
Maintaining strength of quads via exercise that doesn't bear weight w/ active bending is really important--straight leg raises or static wall sits are good.