The ornamental design for a standassistancebelt, as shown and described.
FIG. 1 is a perspective view of a stand assistance belt showing my new design;
FIG. 2 is another perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a left side elevational view thereof;
FIG. 6 is a right side elevational view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines shown throughout the figures on the claimed surfaces depict stitching and form no part of the claim. The broken lines showing handles on the side of the stand assistance belt depict portions of the article and form no part of the claim.