Houston Astros slugger Lance Berkman was put on the 15-day disabled list today for a Grade 2 strain of his left calf. Berkman had been plagued with calf pain since before the All-Star game.
As previously explained (see Boston Celtic Star Kevin Garnett out for Playoffs with Knee Injury , a strain is an injury to a muscle, as opposed to a sprain, which is an injury to a ligament or tendon. However, the grading system to indicate the severity of strain or sprain is the same:
The calf is made up of two main muscles:
The Gastrocnemius is the calf muscle that is visible from the outside of the body. It attaches to the heel by the large Achilles Tendon and originates behind the knee on the thigh bone (femur), It has two heads: the medial and the lateral. When fully developed, these two heads appear to form a diamond shape. Its function is to elevate the heel (known as plantar flexion).
The Soleus muscle is not visible when looking at the body from the outside as it lies underneath the gastrocnemius on the rear of the lower leg. It is most active when doing calf exercises where the knee is bent, such as seated calf raises. The soleus also functions to raise the heel, however, it works to do it when the knee is bent.