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.
Cramping in the calves has several causes, but the true cause is not fully understood. Your history will likely give the most clues. True muscle cramps involve intense muscle contraction and the muscle needs to be lengthened to resolve the spasm. This differs a bit from calf pain from causes other than cramping that results in muscle spasm. Exercise-related cramps are likely caused by muscle fatigue and may involve the Golgi tendon bodies, which normally fire to inhibit the muscle from contracting too hard.