Development of displacement of centre of mass during independent walking in children

The aims of this study were to assess the characteristics of three-dimensional displacement of the centre of mass of the body (CM_b) during walking in healthy children and to compare it with those of young adults. Twenty-one children (11 males, 10 females; age range 1 to 9 years) were recruited from the nursery and school attached to the Université catholique de Louvain, Brussels, Belgium; and three young adults (one male, two females; mean age 26 years 4 months) were recruited from the Rehabilitation and Physical Medicine Unit of the same university. Displacement of CM_b was assessed at different walking velocities in the children and adults by two successive mathematical integrations of ground reaction forces, measured by a large strain-gauge force platform. Displacement of CM_b was controlled for leg length of the participant to eliminate the scaling effect that is dependent on growth. Results showed that vertical and lateral amplitudes of the CM_b when controlled for leg length were greater for children before 4 years of age and that the forward amplitude when controlled for leg length was greater for children before 7 years of age. We conclude that the development of mature human CM_b displacement during independent walking is a gradual neural process, evolving until the age of 7 years.