Muscle knots in the large, superficial calf muscle, theu00a0Gastrocnemius, are located just below the knee. These muscle knots can send a deep, aching pain to theu00a0back of the knee, making it difficult to straighten the leg fully. They can also create sensations of pain down the back of the lower leg to the Achilles Tendon, sharp pain in theu00a0heel,u00a0and a persistent ache in theu00a0bottom of the foot, often mistaken for other conditions. This referred pain pattern can be exceptionally bothersome during walking or running and may even cause intense, involuntary muscle cramps.