Flossing, as described, by McGill in Low Back Disorders is a technique that is meant to increase mobility around the point of an inpingment, in this case the periformis. Have the patient sit on a table with the legs bent at the knee and hanging freely. The patient then fully flexes the cervical spine (i.e. tucks chin), then in a coordinated manner, fully extends the knee, and cervical spine. repeat 5 ot 6 controlled reps. This techniques essentially moves the nerve root as a unit (dosent stretch it), literally flossing through possible areas of inpingment between the cervical SC region and the lower leg (sciatic nerve root flossing). i am by no means an expert in this technique but it is meant to relieve symptoms of impingment of the sciatic......let me know how it goes