FIG. 1 is an inside view of a thumb support, showing my new design;

FIG. 2 is an outside view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a side elevational view thereof;

FIG. 6 is a side elevational view thereof, opposite that shown in FIG. 5; and,

FIG. 7 is a perspective view thereof, in use condition, the broken line showing of the hand and wrist splint is for ililustrative purposes only forms no part of the claimed design.