Instruct: Classify the given review as either positive or negative.
Query: definitely a must have

Having worked as the in-house masseur for the Well and other Whole Earth computer geeks for 4 years, I have searched for something on RSI's. (Thank God/dess for Amazondotcom.) This book is incredibly useful not only for workers themselves, but also for the masseur/euse who also is liable to the very same sorts of injuries. The passive use of the comprehensive exercises by me can be almost as helpful as the active use by the workers themselves. This book should be had by everyone who is experiecing the symptoms of RSI. The author is also one of the master (mistress?) somatic practitioner/healers and it shows.