Conditioning of the spinal stretch reflex: implications for rehabilitation. The purpose of this article is to describe a new technique that can potentially be applied to patients with hyperactive spinal stretch reflexes (SSRs). The progression of clinical research from conditioning of individual muscles or muscle groups (electromyographic biofeedback) to conditioning SSRs is explained. Research data from subhuman primates in addition to the first human experiments are reviewed. Potential applications of SSR conditioning are discussed, as are the issues requiring further delineation and research before the specificity of a training effect can be ascertained. 