A trigger point is defined as a localized tender area within a taut band of skeletal muscle or its associated fascia and characterized by specific patterns of pain radiation during palpation that depend on the location of the trigger point.
Trigger point can be
- Active trigger point is a hyperirritable focus within a taut muscle band which causes pain spontaneously or on palpation and refers pain in a characteristic pattern unique to the muscle.
- Latent trigger point is one which does not spontaneously cause pain but elicits a zone of muscle-specific referred pain on palpation.
- Satellite trigger point is a trigger point that becomes active because it falls within the zone of reference of another trigger point.