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.
If you have a sudden pain in the calf muscle during activity, it is likely the result of a pulled or torn calf muscle. This is called a calf strain or a calf pull. It occurs when part of the muscles of the lower leg (gastrocnemius or soleus) are stretched beyond their ability to withstand the tension.