The ornamental design for an armrestraint for a patient, as shown and described.
FIG. 1 is a top, front isometric view of an arm restraint for a patient according to the new design, wherein the straps extending from the loops are mirror images of one another;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a bottom side view thereof;
FIG. 6 is a right side view thereof; and,
FIG. 7 is a left side view thereof.
The broken lines shown in the drawings illustrate a disclaimed stitching pattern that forms no part of the churned design. The stippled portions indicate fastener elements.