Effects of Manual vs Instrument-assisted Manipulation on Electromyographic Activity and Sympathetic Nervous System

Subject was in supine position, and the therapist applied a manual manipulation with right side bending and left rotation of the neck.

The instrument-assisted manipulation was applied using a handheld Activator IV Adjusting Instrument. Contacts were made firm enough to prevent slipping of the rubber tip but not so firm as to load the spring, in consistence with customary clinical use of the instrument. The spring was then loaded by means of the instrument's trigger mechanism, and the impulse was delivered in an anterosuperior direction, over the posterolateral aspect of the vertebra on the right lamina-pedicle junction of C3.

Subject was in supine position, and the therapist placed ths subject's cervical with right side bending and left rotation but no manual manipulation was applied.