The Collaborative International Dictionary of English v.0.48:

Ischiocapsular \Is`chi*o*cap"su*lar\ (?; 135) a. [Ischium +
   capsular.] (Anat.)
   Of or pertaining to the ischium and the capsule of the hip
   joint; as, the ischiocapsular ligament.
   [1913 Webster]