Foster R M, Margolin L
Child Psychiatry Hum Dev. 1978 Fall;9(1):28-32. doi: 10.1007/BF01463217.
Ten children were tested repeatedly for five motor tasks commonly labeled "soft signs." Finger approximation, walking hell to toe, and the equivocal Babinski improved significantly with practice. These results are interpreted as eliminating these tasks from evidence of "minimal brain damage" and questioning the validity of their inclusion in developmental tests.