Fig. 1From: A data process of human knee joint kinematics obtained by motion-capture measurementThe Optotrak Certus motion capture system. Note: The Optotrak Certus (NDI) Motion Capture System was from Canada. Accuracy: 0.1Â mm; resolution: 0.01Â mm; maximum sampling frequency: 2000Â Hz; mark point frequency: 4600Â Hz; the maximum support marker (number): 512; the minimum marker diameter: 4Â mmBack to article page