§ 13. Reclassification of disabilities. Subject to the limitations in
section fifty-one of this chapter and in section one hundred
twenty-three of the workmen's compensation law as made applicable to
this chapter by section fifty-seven of this chapter, the workmen's
compensation board may at any time, without regard to the date of the
injury, upon its own motion, or on application of any party in interest,
reclassify a disability upon proof that there has been a change in
condition, or that the previous classification was erroneous and not in
the interest of justice.