## 2 Materials and Methods
### Procedures  
Data were collected in the Aris Judo Club, in Thessaloniki, and were to be spread over multiple visits, if necessary. Environmental variables, including consistent lighting conditions, standardized floor surfaces, and controlled room temperature, were maintained throughout data collection for consistency. Additionally, the used tatami mats met the International Judo Federation (IJF) competition standards. All the recordings tookplace after the training sessions, to avoid judokas' schedules being interrupted and to safeguard that athletes were sufficiently warmed up. The judo club principal as well as the athletes were aware of the date and time of our arrival and performed all throws after being given the participant information sheet and having questions answered prior to filming. Dr. [PERSON] was present to tackle any acute injuries or unexpected events during filming. A Huawai 5T with a 48-megapixel camera was used to record the throws. The phone was set up on a 140 cm height tripod, five meters away from the point where the athletes would perform the throws. This was to ensure that the camera would remain stationary to ensure optimal performance and precise tracking. A camera which captures motion of 30 Hz was used for the final recordings. Although the 30 Hz recording frequency is considered sufficient for basic two-dimensional motion analysis, it introduces limitations in capturing rapid movements. This may have resulted in the underestimation of high-frequency kinematic events, necessitating the use of higher-frequency equipment in future studies to enhance measurement precision. Higher-frequency cameras are recommended for future studies to enhance the precision of kinematic measurements. The Huawei 5T smartphone used for recording throws was equipped with a 48-megapixel camera and captured at a frequency of 30 Hz. While this setup provided sufficient resolution for two-dimensional analysis, it may introduce errors compared to high-speed professional cameras. Additionally, the absence of physical markers on participants, due to the gi uniform, necessitated manual tracking, which could result in a margin of error. To mitigate these limitations, repeated measurements and consistent calibration methods were employed. A one-meter calibration marker was placed at a safe distance from the throwing area to ensure measurement accuracy. The mat on which the throws were performed met the specific recommendations from the International Judo Federation (IJF) and were identical to those used during official judo competitions [15]. Participants gave their age, height, and weight and signed a consent form prior to filming. Based on these data, judokas were organized in pairs in order to be of similar weight to a feasible extent, reflecting the method used in competitions. Six different tori performed three STG throws and three TG throws each within their pair, having a total of 18 throws for each technique. One of the pairs performed an STG throw three times with tori kneeling while performing the throw, resulting in both judokas on the ground after the completion of each throw. This was to observe whether there is a difference in shoulder kinematics between the standing and kneeling STG. Thirty-nine (39) throws were performed in total. Throws that were presented incorrectly or not in frame were repeated, and recordings would be completed when each tori performed three (3) throws on uke. The participant flow chart is found in Figure 4. STG recordings were kept separate from TG recordings to avoid mistakes. Between each throw, participants were given adequate time to rest, before proceeding to the next throw, to ensure their safety and the validity of the technique displayed. When all recordings were attained and checked for appropriate quality, each throw was uploaded on Kinovea (version 0.8.15) and edited suitably.