There are two muscles in the back of the lower leg or calf that, if injured, can produce pain when you squat. Squatting stretches those muscles because your foot is flexed upward. Injury to those muscles is called a strain and the severity of the injury determines treatment and the length of healing time.
The two muscles in the back of the calf are the gastrocnemius and the soleus. The gastrocnemius is the larger of the two and is the more visible. It is the valentine-shaped muscle just below your knee. You use this muscle to straighten your foot when you point your toes. The other muscle is the soleus and it is a deeper, smaller muscle. It also is used to point your foot downward.
Identifying the Right Muscle
The gastrocnemius starts above the knee and inserts into the heel. The soleus starts on the back of your lower leg bone, the tibia, and inserts onto your heel. When you squat, you are bending your knee so you are actually taking some stress off the gastrocnemius. No strain is taken off the soleus, so pain that occurs when you squat is most likely due a strain of the soleus muscle.
Muscle strains are graded on a scale of 1 to 3, with 3 being the most severe. With a grade 1 strain, only 10 percent or less of the fibers of the muscle are torn. With a grade 2 the percentage is between 10 and 50 percent. With a grade 3, it is 50 percent or more. A grade 1 may only be a slight tightness or tenderness over the injured area. Usually grade 3 strains will require crutches or a cane to walk.
Initial treatment for a strain is ice and rest. You can elevate that leg to help reduce any swelling. You may also use a compression sleeve wrap to reduce inflammation and add some stability to the injured area. Light stretching and strengthening should begin as soon as you can tolerate it. You can talk to a sports chiropractor or a physical therapist for a rehabilitative program. A massage therapist who specializes is sports massage can also help with reduction of pain and minimizing scarring in the muscle.