Fig. 5. Average values of the limb angle (A) and sagittal plane angular motion at the knee (B) and ankle (C) joints of the left leg during running (2.7 m s^–1) for the examined groups. O, older adults; Y, young adults. The x-axis was normalised as follows: –200% to –100%, flight phase before ground contact of the left leg; –100% to 0%, ground contact of the left leg; 0% to 100%, flight phase before ground contact of the right leg; 100% to 200%, flight phase during ground contact of the right leg. The posterior and anterior position of the COM relative to the midpoint of the foot in vertical direction were defined as negative and positive limb angles, respectively.