The ornamental design for a yarnretentionarm, as shown and described.
FIG. 1 is a perspective view of a yarn retention arm showing my new design;
FIG. 2 is a left-side elevational view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a right-side elevational view thereof;
FIG. 7 is a rear elevational view thereof;
FIG. 8 is an exploded perspective view thereof;
FIG. 9 is a perspective view of a second embodiment of FIG. 1, the only difference being the configuration of the resilient pie-shaped element, it being understood that all other surfaces are the same as those of the first embodiment; and,
FIG. 10 is a perspective view of a third embodiment of FIG. 1, the only difference being the configuration of the ring-shaped attachment, it being understood that all other surfaces are the same as those of the first embodiment.