"A ninja with this trick can strike at an opponent's vital pressure points, causing weakness and intense pain. Whenever the ninja deals sneak attack damage, she also deals 1 point of Strength or Dexterity damage, decided by the ninja. Unlike normal ability damage, this damage can be healed by a DC 15 Heal check. Each successful check heals 1 point of damage caused by this trick. A ninja with this trick receives a +10 insight bonus on this Heal check."
No,unless it said something like below
"equal to the number of the ninja’s sneak attack dice."
Otherwise it just 1 point whenever you deal sneak attack. Or else a level 9 ninja with 5d6 sneak attack dice can take Two Weapon Fightning and attack 4 times a round, which become 20 ability damage
