The |metacarpals| are connected together, and to the surrounding bones, by a number of metacarpal ~ligaments~. One of these is the interosseous metacarpal ~ligament~, which binds the bases (proximal ends) of the |metacarpals| tightly together and to the |carpals|. Another is the deep transverse metacarpal ~ligaments~, which span the heads (distal ends) of the |metacarpals|, linking the |metacarpals| together at some distance apart. This arrangement provides the necessary lateral support which keeps the bones of the hand in the appropriate array. Because this is achieved by ~ligament~ rather than bone, the hand has some latitude to compress and expand laterally, as well as curve longitudinally.
