When you find a "painful arc"?
What is a "painful arc"?
You could define a painful arc as a painful passage during a movement, active or passive, inbetween two painfree passages.
This is found very often in the shoulder and is considered being a “localizing sign”: im combination with other tests from the basic examination it gives accessory information about the presumeable localisation of the lesion.
Painful arc in the shoulder
In the shoulder we can find a painful on active elevation or on medial rotation. Very often that also points in the direction of a chronic subdeltoid bursitis.
In exceptional cases the PA cannot be detected in an active way (e.g. because the movement is too painful), but only in a passive way.
In that case a severe symptomatic calcification of the supraspinatus might be suspected (that’s an empirical finding).
Painful arc related to spine problems
This can also be found during the straight leg raise test and is a typical finding pointing in the direction of a symptomatic small lumbar internal derangement.