A surgical retractor adapted to develop the interval between the gastrocnemius and soleus to facilitate one or both of gastrocnemius and soleus recession to treat equinus is disclosed. Particular forms of the present disclosure include a retractor having handles extending transversally to the retractor head such that the handles may be used to manipulate and actuate the instrument with its head positioned through an incision and into the interval between the gastrocnemius and soleus, with the handles extending either distally or proximally from the incision site so that such handles do not interfere with the surgical procedure. In other illustrative embodiments, the retractor head can include a gastrocnemius retractor and a soleus retractor, each of which include a plurality of guides operable to guide the incision of the fascial layer of the gastrocnemius and soleus, respectively, to effect intermuscular fascial lengthening to relieve equinus. In further illustrative embodiments, ramped guide surfaces may cooperate with a scalpel to vary the depth of the fascial incision along its length. Concave outwardly facing surfaces of the retractor head may, in certain embodiments, be utilized to cup the gastrocnemius and soleus during the procedure.