I am also 40 and have had sharp pains in my thigh muscles for the last couple of weeks. It almost feels as though a long needle is stuck in my thigh muscles, but sharp, very sharp. Then the sharpness becomes dull.
i having the same pain, tho my back or other areas are not affected, wonder what it is>> just severe thigh pain to the knee only, one leg, my left one
Hmmmm. You may have slept in a funny position or something and thrown it out of place. You might want to check with your chiro to see if there is anything they can do. Is the pain more in the joints or is it in your thigh/back muscles? If the pain is in your joints I don't know, maybe check with a docttor as well. If you muscles are what is aching you may be able to help it with some over the counter meds/supplements. Below is some info tthat I found on magnesium and it can help a lot with sore muscles, as well as being good for you body in many other situations as well. I hope this is helpful!
"Magnesium's role in relaxing muscles. Another primary role of magnesium is to work with calcium to help regulate the body's nerve and muscle tone. In many nerve cells, magnesium serves as a chemical gate blocker - as long as there is enough magnesium around, calcium can't rush into the nerve cell and activate the nerve. This gate blocking by magnesium helps keep the nerve relaxed. If our diet provides us with too little magnesium, this gate blocking can fail and the nerve cell can become overactivated. When some nerve cells are overactivated, they can send too many messages to the muscles and cause the muscles to overcontract. This chain of events helps explain how magnesium deficiency can trigger muscle tension, muscle soreness, muscle spasms, muscle cramps, and muscle fatigue especially in the back and legs where some of the body's largest muscles live."
http://www.jigsawhealth.com/products/magnesium_supplement.html