Table 3. The mean absolute error of the knee valgus angles and t-test results using the three-dimensional motion analysis as a reference. Human OpenPose P value Ground contact 3.5 (2.5-4.5) 3.4 (2.2-4.6) 0.898 Lowest COG after landing 4.1 (2.6-5.6) 5.2 (3.4-7.0) 0.319 Excursion of the knee valgus angle 3.5 (2.5-4.4) 4.2 (3.1-5.4) 0.286 Throughout the landing phase 3.2 (2.1-4.4) 2.4 (1.9-3.0) 0.194 Mean (95% confidence intervals), degree; P value by unpaired t-tests (Human vs. OpenPose); Human: human visual detection-based motion analysis, OpenPose: OpenPose-based motion analysis, COG: center of gravity.