A spinal manipulation instrument, system, and method may use a driving rod to move instrument arms toward or away from one another to compress or distract between selected vertebrae to which the arms are connected. Two arms may be coupled to the driving rod. A threaded collar may axially engage one of the arms, to translate that arm along the driving rod with respect to the other arm. The other arm may be at a fixed axial location or driven by another, oppositely-oriented thread. The arms may be highly adjustable to accommodate a wide range of anatomical variation between patients. Attachment members may be modular to interchangeably couple the arms across multiple platforms.