After the stratosphere come the mesosphere and thermosphere. First is the mesosphere, which extends upward to 50 miles above the surface. After the mesosphere, we have our layer thermosphere, which extends from about 50 miles above the surface of Earth to about 600 miles above our planet. Beyond that is the exosphere, which is the layer that turns into outer space at the edge. What Do We Know About the Mesosphere?
Calf and hamstring pain can be caused by sciatica, a condition in which your sciatic nerve is irritated. A pulled hamstring muscle near your knee joint or a pulled calf muscle near the knee induces pain. The bursas lubricating and cushioning your knee joint and the pelvic attachment of your hamstring muscle can become irritated and swollen, causing pain.
1 Baker's Cyst: A Baker's cyst is not a true cyst. Rather, it is a collection of knee-joint fluid that has pooled in the back of the knee. 2  Blood Clots: A blood clot needs to be considered as a cause of calf pain, especially when the calf pain is not the immediate result of an injury. Blood clots can form in the deep veins of the leg, causing a blockage in circulation. This may cause swelling and pain in the calf. Blood clots are more common in the days and weeks after injuries and surgical procedures. Knowing if you have a blood clot is important. Without treatment, the clot can travel to the lungs, causing difficulty breathing. Leg Cramps: Cramps in the leg muscles are a common cause of calf pain.