Creeping patterns of human adults and infants.

The patterns of swing and support for the hands-and-feet or hands-and-knees gaits (creeping) of human adults and infants are compared based on data from a number of studies. Human infants show considerable variability in their creeping gait patterns, whereas adult patterns are less variable and fairly consistent after a few minutes of practice. Creeping on hands-and-knees appears to dictate a gait pattern characteristically different from creeping on hands-and-feet. The highly inefficient nature of adult creeping supports the view that our early hominid ancestors were poorly adapted to quadrupedal locomotion. Data obtained from high-speed film analysis of human creeping patterns show that the number of foot lengths per stride in creeping is about twice that for normal upright walking at the same speed. The support pattern of human creeping is different from that of nonhuman primates. These findings are discussed in the context of debate concerning the origin of the Laetoli hominid footprints and the knuckle-walking hypothesis.