The ornamental design for a wall mounted back scrubbingbrush, as shown and described.
FIG. 1 is a perspective view of a wall mounted back scrubbing brush showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof, the right side elevational view being a mirror image thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof; and,
FIG. 7 is a left side elevational view thereof showing the wall mounted back scrubbing brush in use.
The partial human figure drawn in broken lines in FIG. 7 is environmental included to assist in showing how the claimed design may be used, and forms no part thereof.