SUMMARY. This article reports a series of three case studies where the author carried out a spinal mobilization treatment concurrent with the patient’s attempt to contract a chronically weakened muscle or muscle group. All of the cases describe enhancement of the contraction of the posterior crural muscles post trauma. A brief discussion of the results and potential mechanisms by which the results may have been achieved is presented. This involves reference to proprioceptive neuromuscular facilitation (PNF), muscle energy techniques and to spinal mobilizations with limb movements. Copyright 1997 Harcourt Publishers Ltd.