orthokinetics /-kinet″iks/ [Gk, orthos, straight, kinesis, movement] , 1. a therapy for hypertrophic osteoarthritis in which an effort is made to change muscular action from one group to another to protect a joint. 2. a therapy for spasticity that uses an orthotic device to enable contraction of one muscle while inhibiting its antagonist. 3. the movement of microscopic particles in the same direction during sedimentation as a result of the effect of gravity on Brownian motion.
