Biomechanical Analysis Methods to Assess Professional Badminton Players' Lunge Performance

This method can help answer key questions biomechanical fact about the lunge performance of badminton players. The main advantage of this technique is that it reproduces actual badminton moments. So the data isn't highly reliable.

The implications of this technique is tend toward therapy of sports injuries because changes in the joint over angle while playing badminton are likely to result in injury. On the day of the evaluation have the subject wear a T-shirt and tight shorts and the same brand of badminton shoes as the rest of the subject's hight in the study. Measure the subject's height millimeters and weight in kilograms, as well as the length of both the left and right legs in millimeters from the superior iliac spine to the ankle internal condyle, the knee widths in millimeters from the medial to the lateral knee condyle, and the ankle widths in millimeters from the medial to the lateral ankle condyle.

Palpate to identify the anatomical landmarks and shave any body hair as needed, followed by disinfection with alcohol, then mark the skin over the anatomical bony landmarks and paste the eight markers on the identified areas on each leg. When all of the markers have been placed ask the subject to perform a right forward lunge naturally, to make sure that the markers on their lower limbs are captured by the cameras. Have the subject continue to perform the right forward lunge at a comfortable low speed in the simulated court until they can perform the movement steadily.

After having the subject perform some auxiliary exercises to warm up, ask the subject to perform the right forward lunge at a comfortable high speed in the simulated court until they can perform the movement steadily at this speed. Next, ask the subject to put their right leg in the designated area and underhand strike the shuttlecock. Then instruct the subject to perform a maximal right forward lunge from the start position, and underhand strike the shuttlecock to the backcourt, while making sure that the right foot naturally steps on and fully contacts the forest platform as they pass before returning to the start position.

For static calibration, open the data management program to create a new database, and select the location for saving the data file. Enter the name of the new file and select Based On and Clinical Template, click create, select the subject's name, and click Open. To create a new session with the subject's information, click New Patient Classification, New Patient, and New Session.

Click Go Live, at the beginning of the trials. Select Session to capture the data, and return to the Nexus pane. Click Subjects and New Subject renaming the trials as necessary, and select Split Horizontally in graph to view the trajectory count.

Then, check that the number of markers is 16, that there is no unwanted light pollution, and that all of the markers have been captured. If all the markers are in view, in the Subject Preparation window, select Subject Capture, and click Start to begin capturing the static data, having the subject remains still until 200 frames of images have been captured. Then click Stop and Run to reconstruct the pipeline for constructing the marker data.

Select Label and apply the appropriate labels to the corresponding markers in the markers list. When all of the labels have been applied, click Save, and press the Escape key to exit. Click Subject Preparation and select the Static Plugin Gate in the subject calibration drop down menu.

Click Option in the newly displayed frame range window and select Left Foot and Right Foot in the pop up window. Then click Start and Save. To start the dynamic trials, have the subject returned to the start position, and click Go Live and Capture.

Set the trial type and the session in order and enter the trial name. Click Start to begin capturing and have the subject first perform a fast right forward lunge six times, with the last step hitting the force plate each time. After a two minute break, have the subject performed six lunges, naturally.

After another two minute break, have the subject performed six maximal right forward lunges before returning to the start position, and click Stop to end the data capture. In this study, no significant difference was observed in the mean vertical ground reaction force of the initial impact peak, the secondary impact peak, and weight acceptance phases of the evaluation between the professional and amateur badminton players. The vertical ground reaction force of the professional players in the drive-off phase was markedly higher than that of the amateur players however.

Results from independent t-tests revealed a greater range of movement in the ankle dorsiflexion and plantar flexion on the sagittal plain, demonstrated a significant difference on the frontal and horizontal plains. Further, a significant difference between the professional and amateur players in the external, internal rotation of the knee was observed on the horizontal plain with a larger range of movement also measured in the abduction, adduction on the frontal plain and in the flexion, extension on the sagittal plain. The amateur players presented a smaller planter flexion moment or a greater dorsiflexion moment in the four phases when performing a lunge, while the professional players exhibited a greater eversion moment in the weight acceptance phase when performing a lunge with a smaller internal rotation moment or greater external rotation moment in the drive off phase.

In addition, the professional players showed a greater extension moment in the knee in the secondary impact peak phase and a greater abduction moment in the initial impact peak. While attempting this procedure, it's important to remember to pay attention to the continuity of the player's movements.