Spinal clamps were devices implanted into the spinal columns of Borg drones.

After allowing herself to be assimilated for a mission to aid the inhabitants of Unimatrix Zero in 2377, Captain Kathryn Janeway remarked to Seven of Nine that though The Doctor had removed her spinal clamps, "it'll be a while before [she's] playing hoverball again". (VOY: "Unimatrix Zero, Part II")