Analysis On Sports Biomechanical Characteristics Of The Flag Gate Crossing Technique Of The Elite Men’s Alpine Slewing Athletes In Jilin Province

The 2022 Beijing Winter Olympics were successfully held,and China’s ice and snow sports have received great attention from all sectors.This year’s Winter Olympics has also created history in multiple indicators.However,alpine skiing has always been a weakness in China’s snow sports,and optimizing flag gate techniques is a key factor in improving competitive ability.This study analyzes the biomechanical characteristics of the flag gate crossing technique of outstanding male alpine skiing slalom athletes in Jilin Province,explores the sports laws of alpine skiing slalom events,and puts forward scientific suggestions for improving athletes’ competitive ability.This study selected all members of the Jilin Province alpine skiing team as the test subjects(n=7),aged 17.57 ± 2.23(years old),height 176.71 ± 7.89(cm),weight 68.57 ± 10.71(kg),and training duration 4.86 ± 2.41(years).In this study,the camera array composed of six German Basler high-speed cameras,the American Biovision multi-channel motion bioelectricity telemetry recording and analysis system and the Belgian Footscan insole plantar pressure test system were used to collect data in an internal synchronous manner.In this test,7 taxies of 7 subjects were collected,with 49 taxiing data in total.The kinematics data collected by each subject in a single time was 3 flaggates,14 muscles were collected by bioelectricity,and the plantar pressure test was conducted in 8 collection areas consisting of 96 points on the left and right sides,with 1225 sets of original data collected.The collected kinematics images were analyzed with German Simi-motion8.0 technical motion analysis system,and the differences between the data were compared with Mann Whitney U test(non parametric test);The bioelectricity data was imported into Matlab2021 a for filtering(10Hz-125Hz),and then the root mean square amplitude and integrated EMG data were obtained according to the division of action stages.The root mean square amplitude reflected the change of activation intensity of the subject’s single muscle in each action stage,and the integrated EMG reflected the change of the subject’s muscle contribution ratio in different action stages during sliding;The plantar pressure data is analyzed using Footscan’s built-in software to calculate the sum of plantar pressure and pressure,as well as the relative pressure and pressure of different zones.Reflect the changes in plantar pressure and pressure of the subjects through this data.Finally,three consecutive complete data of excellent athletes were selected to analyze their three consecutive flaggate movements,with a focus on analyzing the biomechanical characteristics and patterns of one left and two right flaggate movements of both legs.The research results indicate that:1.In terms of kinematics,the athletes spend the shortest time in the initial stage when passing the flag gate,and the longest time in the turning stage,which is the same as the result of sliding distance.The ending stage has the fastest speed and the starting stage has the slowest speed;There was no significant change in the hip joint angle on the mountain board side after two consecutive rotations and two rotations in the same direction,while there was a significant change in the hip and knee joint angles on the other mountain board sides and downhill board sides.2.In terms of bioelectricity,the subjects’ bilateral external oblique muscles,rectus femoris,medial femoris and tibialis anterior muscles have a high muscle contribution rate,which is the main force generating muscle group that can reach a high peak at different stages after completing the flag gate technique.3.In terms of dynamics,the pressure on the soles and heels of both sides of the athlete’s feet is relatively high when passing through the flaggate technique,while the pressure on the toes and arches of both sides is relatively low.The research conclusion is as follows:1.The excellent male alpine skiing slalom athletes in Jilin Province have a longer displacement distance during the turning stage when turning left and passing through the flag gate,demonstrating insufficient ability in the turning stage of non dominant side direction passing through the flag gate technology and poor technical ability in connecting adjacent flag gates before and after.2.Athletes experience instability on the downhill side of their bilateral knee joints through two adjacent and identical flaggate passes,while also exhibiting potential leg asymmetry.3.The participation of the core muscle group and gluteus maximus during the turning phase of athletes turning left through the flag gate is low;When turning to the right and passing through the flaggate,the participation of the core muscle group and gluteus maximus is high.4.When athletes perform flag gate techniques,the sole area of their feet is the main stress area,and the pressure on their toes and arches is relatively small.The peak pressure in the arch and heel areas occurs at the junction before and after each rotation through the flaggate.