This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
The deep fascia of the leg is attached above to the tubercle of the tibia, the tuberosities of the tibia, and the head of the fibula. It gives off two septa from its under surface, one in front separating the abductor or peroneal group from the extensor group, and another posterior which separates the abductor group from the soleus posteriorly. This latter covers the deep flexors and separates them from the muscles of the calf and is continued across to be attached to the medial (internal) edge of the tibia. The deep fascia of the leg blends with the periosteum over the medial (internal) surface of the tibia and also with that of the lateral (external) surface of the fibula in its lower fourth. At the ankle the deep fascia is continued on through the annular ligaments.
The muscles of the leg take their origin partly from these fasciae, and subsidiary septa pass between the muscles.