After working in the garden for a while, my knee hurts

My aging effect shows that when I worked in my garden for sometimes, my knee and back hurts. I tried taking Glucosamine and Calcium, it helps some. The other day when I was complaining about this to my cousin, he told me to tried a supplement that he found to be quite effective. The supplement is called "Hyaluronic Acid". He said you can buy it in capsule form. I searched this in google and found a lot of information about this particular supplement especially for joint growth.  I then ordered a bottle from Amazon.com to try it out. It has been more than a week now and the result is working. My knee pain is gone and I can actually play tennis without fear of getting my knee pain.  Working in my garden, I feel no pain. What a relief!  I told my doctor about this supplement, he also recommended that I should continue to take this supplement.