NA is usually successful in straightening contractures caused by cords in the palm, less so but with improvement with cords in the fingers. There are lots of historical posts here from people who have been happy with NA. Since the cords are severed and not removed the contracture often returns, and some folks do repeat treatments every couple of years if necessary. Search on Dr Pess or Denkler or Manet Chopin in the forum to get examples. Dr Pess also has a video on YT.