Abstract: The addition of a thumb to a bucket of a work machine allows more uses for the work machine than having only the bucket. Having an attachment device locatable along the length of the stick permits different thumbs and different implement-positioning devices to be used with different work machines, adding more flexibility of use. The disclosed method and apparatus is for an attachment device for attaching an implement-positioning device to a load-bearing member, comprising a base member, a coupling member for adjustably attaching the base member to the load bearing member, and an attachment means for attaching the implement-positioning device to the coupling member.