Muscle EMG in toe walking. Amount of soleus EMG in swing (A–C) and tibialis anterior EMG in stance (D–F) during heel (A and D) and toe walking in typically-developed children (B and E) and during toe walking in children with cerebral palsy (C and F) as a function of age (in years). Each symbol illustrates data from a single child. Full lines indicate regression lines. Dashed lines indicate 95% confidence intervals. Average EMG levels in the population of 15 typically-developed adults have been marked in A, B, D and E as horizontal dashed lines and open circles with vertical bars indicating standard deviation. CP = cerebral palsy; Sol = soleus muscle; TA = tibialis anterior muscle; TD = typically-developing.