The ornamental design for a wrist/elbow rest, as shown and described.
FIG. 1 is a perspective view of a wrist/elbow rest, showing my new design;
FIG. 2 is a front elevational view of the invention;
FIG. 3 is a rear elevational view of the invention;
FIG. 4 is a top plan view of the invention, the bottom plan view being a mirror image thereof; and,
FIG. 5 is a right-side elevational view of the invention, the left-side elevational view being a mirror image thereof.
The broken line showing an arm in FIG. 1 is included for the purpose of illustrating a wrist/elbow rest in use, and forms no part of the claimed design.