FIG. 1 is a perspective view of an ankle clamp illustrating my new design;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is another perspective view thereof.

The broken lines in FIG. 1 illustrate environmental structure and form no part of the claimed design. The broken lines in FIG. 7 illustrate portions of the ankle clamp which form no part of the claimed design.