The target gets a health save.
When you use this technique on a Heavy Attack, you may spend 1 more stamina to increase the save DC by 5.

Fail:
Every 5 ft. the target moves costs an extra 5 ft. of movement,
and the target has disadvantage on health (reflex) saves,
and tests of Agility
until the target is healed.
(Any amount of healing ends this condition.)

Pass:
The target’s speed is reduced by 5 ft. during their next turn.

You cannot use other techniques with this attack.

A target can only suffer from one Hamstring at a time.