## 2 Materials and Methods
### Protocols  
Drop-jumps were conducted to characterize landing mechanics in biomechanical testing environments including the two force plates (Kistler 9287C, 60 cm \(\times\) 40 cm) to collect the GRFs at 1000 Hz and 10 high-speed motion capture cameras (Vicon motion analyzer MX, type of T20 and T20S) were used to sample whole body kinematics at 250 Hz. For drop-jumps, a box with a height of 30 cm was placed 10 cm away from the force plate, and prior to their jump participants would stand 1 cm from the edge of the box. This box was placed directly between two adjacent force platforms, where the box was positioned 15 cm away from the edge of the platforms (Figure 1). One hour before the experiment was initiated examiners set the VICON cameras, force plate, retroreflectors, computers, and recorders setting and prepared the clothes for the subjects. Every subject was provided general information about the experimental protocol. Appropriate clothing consisted of own running shoes, tight-fitting top and high-cut running shorts. The warm-up consisted of a 10 min jog followed by light stretching. Participants completed a 5 min warm-up and 5 min self-directed stretching, prior to data collection. General anthropometric measures (height, and weight) were taken for each participant by the same researcher. As a specific warm-up, all the participants practiced five landing tasks to become accustomed to the movements before data collection. Forty-seven retro-reflective markers were applied bilaterally on specific body landmarks over the right hand, right wrist lateral side, right wrist medial side, right elbow lateral side, right elbow medial side, right shoulder front side, right shoulder back side, right acromial, left hand, left wrist lateral side, left wrist medial side, left elbow lateral side, left elbow medial side, left shoulder front side, left shoulder back side, left acromial, right toe, right ball lateral side, right ball medial side, right heel, right ankle lateral side, right ankle medial side, right knee lateral side, right knee medial side, right trochanterion, left toe, left ball lateral side, left ball medial side, left heel, left ankle lateral side, left ankle medial side, left knee lateral side, left trochanterion, top of head, right ear, left ear, suprasternal front, suprasternal back, right rib, left rib, xiphoid, xiphoid back, right anterior-superior iliac spine, left anterior-superior iliac spine, right posterior-superior iliac spine, and left posterior-superior iliac spine (Figure 2). Figure 1: Global coordinate system and force plate orientation (Kistler 9287C). Figure 2: A total of 47 reflective markers were placed on each subject. Seven participants were required to partake in two different landing techniques and were permitted three practice trials for each technique. Five successful trials, verified by video, were collected for each trunk posture. If participants did not place the dominant foot (which was determined at the beginning of experiment by asking each participant; all of them were aware of their dominant foot) on the force plate, or lost balance and did not execute the task with the appropriate landing technique or did not perform the appropriate task based on the cue generated by the software, the trial was not successful and discarded from analysis. Participants were initially instructed to stand on the edge of the box with feet 35 cm apart. They stood on the step on their dominant leg with the knee of the other leg bent at approximately 90\({}^{\circ}\), with neutral hip rotation, arms crossed/with their hands on their hips. Subjects for single-leg landing stood on the opposite foot with their hands on their hips and landed with the foot in the center of the force plate. Then, drop-landings were performed in three trunk positions (LFL, URL, and SSL) randomly. For double leg landings, participants were instructed to drop off the box, with both feet landing simultaneously and entirely on the force platforms (one platform per leg) to complete five trials as landed.