Fig. 195. Dorsum of (Left) Foot with Muscles and Tendon-sheaths. 



The Fascia of the Dorsum of the Foot has been removed except the Superior 

 and Anterior Annular Ligaments. The Tendon-sheaths have been opened except 

 the cul-de-sac at their extremities, the length of which is indicated by an arrow. 



The Superior and Anterior Annular Ligaments keep the Extensor-Tendons 

 in position during movements at the ankle; this arrangement is perfected by a 

 separate compartment for each tendon with its own special sheath in order to 

 avoid any friction. 



The Sheath of the Anterior Tibial Muscle commences 21/2 inches above 

 the Intermalleolar-Line (between the tips of the Malleoli) and ends usually at 

 Chopart's Joint. The Sheath of the Long Extensor of the Big Toe begins 

 ^4 inch above the Intermalleolar-Line and extends down to LiSFRANC's Joint. 

 A second and even a third Synovial Sheath may be present (Fig. 195) in connection 

 with this tendon. 



The Long Extensor of the Toes and the Third Peroneal Muscle occupy 

 a common sheath which commences lower down than the sheath of the Anterior 

 Tibial and extends to the middle of the External Cuneiform Bone. 



A sling-like ligament which arises in the Sinus Tarsi assists in keeping 

 these tendons in place under the Annular Ligament. Sometimes an extensive 

 Bursa is found between this Ligament and the Neck of the Astragalus. 



Many other Synovial Sacs may be present: those between the heads of 

 the Metatarsal Bones (Intermetatarso-phalangeal Bursa) are quite frequent. Whenever 

 tendons pass over bony prominences, small synovial sacs are placed to act like 

 cushions; even where the Lumbrical Muscle winds around the shaft of the first 

 phalanx these are found. Again Subcutaneous Bursae occur whenever there is 

 pressure of skin against bone especially under "Corns"'. The Bursae over the 

 Malleoli are fairly constant as well as those on the lateral aspect of the Heads 

 of the I St and 5th Metatarsal Bones, and those over the Heads of the ist Phalanges. 



