OBJECTIVES: To provide a reliable data base for comparison of pathological gait with normal gait in children. A kinematic study of normal gait patterns will be carried out from the onset of independent walking through seven years of age. Cadence, right and left step length, stride length, walking velocity, stance and swing phase duration and joint angle measurements of hip, knee and ankle joints in sagittal, frontal and transverse planes will be made. In addition, force plate measurements of vertical load, force and aft shear, medial/lateral shear, torque and center of pressure will be made. External joint torque will be calculated and energy output in walking will be measured to provide kinetic information. Femoral antetorsion and neck shaft angle will be determined by fluoroscopy technique with image intensification. Joint angle measurements, linear displacement measurements and force plate calculations will be correlated to establish evolving gait patterns from independent walking to seven years of age. We will seek to establish the specific gait patterns and identify the specific gait parameters which are the best indicators of the evolution of mature gait. The specific goals are to relate the function of walking to motor skeletal maturation and to establish sufficient data to compare pathological gait patterns with reliable normal controls at each age through seven years.