THE EFFECT OF DIGITAL FILTERING PROCEDURES ON KNEE JOINT MOMENTS IN SPRINTING

Inverse dynamics analyses are commonly used to obtain resultant joint moment data during sprinting. This study aimed to determine the effects of using different combinations of cut-off frequencies applied to the kinematic and kinetic input data on the determined knee joint moments. Input data from a sprinter during the first stance phase were recorded, and ten different combinations of cut-off frequency were applied. When the kinetic cut-off frequency exceeded the kinematic one, as is common, larger peaks and rapid fluctuations were evident in the knee joint moment soon after contact due to inconsistent frequency content between the input data. In contrast, when the cut-off frequencies were matched, the peaks and fluctuations were minimal, and it is suggested that they may be anomalies of data processing and not genuine aspects of sprint kinetics