Two experiments were carried out to investigate the influence of asymmetric muscular imbalance in children and adolescents on the location of apparent vertical and on the laterality of apparent movement. Four groups of 10 Ss each were tested. Two groups consisted of children, one with right leg paralysis, the other with left leg paralysis. The remaining two groups were composed of adolescents, one with right leg paralysis, the other with left leg paralysis. Experiment I showed that adolescent paralytics locate the apparent vertical opposite to the side of paralysis, whereas paralytic children locate the apparent vertical to the side of paralysis. Experiment II showed that paralyzed children and adolescents report apparent movement predominantly away from the side of paralysis. These results, viewed within the framework of sensory-tonic field theory, support the assumption that muscular involvement affects perceptual experience. (PsycINFO Database Record (c) 2006 APA, all rights reserved)