Scaling of Dynamics in the Earliest Stages of Walking

Although the description of mature walking is fairly well established, less is known about what is being learned in the process. Such knowledge is critical to the physical therapist who wants to teach children with developmental delays. The purpose of this experiment was to test the notion that learning to walk efficiently involves fine-tuning the body’s controllable stiffness (by co-contraction and isometric muscle contractions against gravity) to match (at a 1:1 scaling) the gravitational (pendular) stiffness of the swing leg. Subjects The study participants were 7 children with typical development and the newly emerged ability to walk 6 steps without falling (ages 11 months to 1 year 5 months at the onset of walking). Methods Pendular stiffness and spring stiffness were estimated from the equations of motion for a hybrid model with kinematic data as children walked over ground. Testing occurred once per month for the first 7 months of walking