Extract Experimental Data¶
The DU experimentally measured kinematics and kinetics are reported in .csv files. These files contain the experimentally measured tibiofemoral joint loads and the corresponding kinematics. The time synchronized experimental data is used to parse the different test cases. During preprocessing for model calibration, the indices of the desired points in the experimental test case are defined, and these indices are later used to extract specific kinematics and kinetics from the time-synced data in the .csv files.
The experimentally measured kinetics and kinematics are used to semi-automatically parse the experimental data. Similar to the time synchronization methods, a custom user interface will plot the experimental kinematics and kinetics curves. The user will select a portion of the load curve that spans the apparent beginning of the test case to the apparent end of the test case (Fig. 4). The knee finding algorithm is used to define the beginning and end of the laxity test (Fig. 4). The indices defined by the knee points are used to define beginning and end of the test case. This will be repeated for every test case that is used in the study.

Fig. 4 (top) The anterior force during the entire anterior-posterior drawer test, and (red) a portion of the curve that appears to include the start and end of an anterior drawer laxity test. (bottom) The selected portion of the anterior force curve, and (black) the “knee” points of the (x) start and (circle) end of the laxity test. Note that this example does not show the other kinematic or kinetic degrees of freedom that may be used to parse the desired test cases.