The Motion Analysis Corp. jumping analysis application creates measurements of the critical biomechanical parameters during a drop jump or vertical jump. It supplies a complete kinematic and kinetic report of the legs as well as measurements about the player's technique. Data from drop jumps can be used to indicate a potential for Anterior Cruciate Ligament injury. Both kinds of jumps can be used to compare the biomechanics among players, or show comparisons of the same player over time. This guide will step through the procedures to properly acquire the jumping trials and then operate JumpTrak.
What you need
Motion Analysis Corp. Motion Capture system. 29 Retroreflective Markers and configured as shown below:
|1||Top.Head||Topmost spot of the head|
|2||Front.Head||Front/center of the head|
|3||Rear.Head||Back/center of the head|
|4||R.Shoulder||End of the Clavicle (collar bone) - top of shoulder|
|5||R.Offset||Centered on the right clavicle|
|6||R.Elbow||Lateral epicondyle of the humerus|
|7||R.Wrist||Styloid Process of the Ulna|
|8||L.Shoulder||End of the Clavicle (collar bone) - top of shoulder|
|9||L.Elbow||Lateral epicondyle of the humerus|
|10||L.Wrist||Styloid Process of the ulna|
|11||R.ASIS||Over the right front of the hip|
|12||L.ASIS||Over the left front of the hip|
|13||V.Sacral||Over the base of the spine, L5-S1 joint|
|14||R.Thigh||About 1/3 the distance from hip joint to knee joint|
|15||R.Knee||On the Lateral Condyle|
|16||R.Knee.Medial||On the Medial Condyle|
|17||R.Shank||About 1/3 the distance from knee joint to ankle joint|
|18||R.Ankle||On the Lateral Malleolus (ankle bone)|
|19||R.Ankle.Medial||On the Medial Malleolus (ankle bone)|
|20||R.Heel||Centered on the heel|
|21||R.Toe||Over the base of the second toe|
|22||L.Thigh||About 2/3 the distance from hip joint to knee joint|
|23||L.Knee||On the Lateral Condyle|
|24||L.Knee.Medial||On the Medial Condyle|
|25||L.Shank||About 2/3 the distance from knee joint to ankle joint|
|26||L.Ankle||On the Lateral Malleolus|
|27||L.Ankle.Medial||On the Medial Malleolus (ankle bone)|
|28||L.Heel||Centered on the heel|
|29||L.Toe||Over the base of the second toe|
Data Collection Setup
Data collection for JumpTrak is similar to the standard collection process. There are some settings for calibration and data collection that you should use that will help ease the process. Learn about the recommended data collection settings in Data Collection Setup.
You should already be familiar with how to collect 3D data using Cortex. However, JumpTrak requires some specific collection procedures to ensure correct calculations. Trial Collection describes the recommended workflow to collect your trials.
Drop Jumps: Once prepared, the subject should drop directly down off the box and immediately perform a maximum vertical jump, raising both arms towards the overhead target. If an overhead target is not used, the test subject should be instructed to land and jump as high as possible as if reaching for a basketball rebound.
Running the JumpTrak Application
Now that the trials are collected, data are clean and events selected, you can use the JumpTrak Application to perform the calculations and generate the reports. Click to watch the Video Tutorial on how to use the JumpTrak Application:
To run JumpTrak, Click Applications>JumpTrak:
Complete the Subject Information fields for the jumper: Now Select the Trials that you want to process with JumpTrak, and click on the Generate Reports button. The Kinematics and Kinetics graphs will be populated for the last selected trial. Check that the graphs are filled and do not have errors. If you want, you can print out these reports by right clicking in the presentation graphs pane and selecting File>Print Graph Image. Open the MS Excel program and select the trial that you want to view. The Excel workbook will have three tabs. A listing of the data will be on the first tab, with the Graphs and WebReport on the other tabs.
Here is an example report in Excel: sample1_report.xlsx
There is a table that has the jumping parameters:
A green check box and a red check box will indicate within or outside recommended ranges to predict risk of injury to the Anterior Cruciate Ligament.
The JumpTrak Excel report also has an "Interactive Report" where you can view Hip, Knee and Ankle Angles, Velocities, Moments and Powers for each limb or for both:
Click within each box to select the desired Joint, Side and Axis.
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