Instruct: Classify Amazon reviews into positive or negative sentiment
Query: poor or no explanations of planes, levers, biomechanics

The title is deceiving. There are no explanations of levers, planes, moments of inertia, etc. In a nutshell, all throws are based on the principle of the moment of a couple, that is, initiating rotation about some point by applying equal and opposite forces; there is no science behind the writing in this book. There are excellent judo books which show sound principles of throws and sweeps, such as "Street Stoppers" and "effective combat throws"!