Analysis Of Surface EMG Characteristics Of Flat Bench Presses With Different Holding Distances Under Increasing Load

Research purposes: This article aims to use surface electromecha-nical technology to analyze the change characteristics of IEMG% MVC of three kinds of gripping flat bench presses under increasing load.The main muscles and their specific working characteristics under the push action and increasing load state provide a scientific theoretical basis for fitness enthusiasts.Research method: This study will use surface EMG testing and analysis methods to study the most commonly used flat bench presses in fitness and various special trainings.The subjects are 20 students from the Physical Education College of Sichuan Normal University,with 1 year or more Fitness experience.The load mode is incremental load,incremental load level: 30% 1RM,50% 1RM,70% 1RM,90%1RM,bench press grip distance is 100% SW,150% SW,200% SW.Interception of data: Select the integrated electromyography value IEMG of 2s in the push-up phase.The maximum static value MVC of each test muscle of each subject was measured.Finally,the integral muscle IEMG% MVC standardized by the ratio of IEMG and maximum static value MVC was used for analysis.Research results: 1.Comparison of IEMG% MVC between different load 30%1RM,50% 1RM,70% 1RM,90% 1RM groups at 100% SW grip distance,IEMG%MVC between different loads are significantly different(P < 0.01);2.The difference between biceps IEMG% MVC100% SW grip distance and 150% SW grip distance is-0.755(95% CI:-1.514 ~ 0.004),P = 0.051,not statistically significant,100 The difference between% SW grip distance and 200% SW grip distance is-1.641(95% CI:-2.850 ~-2.580),P = 0.007,with statistical significance;the difference between150% SW grip distance and 200% SW grip distance The value was 0.886(95% CI:-1.742 ~-0.029),P = 0.042,with statistical significance.3.The IEGGMVC% of the forearm flexor is between the 100% SW grip distance and the 150% SW grip distance,P = 0.006,which is statistically significant.P = 0.001 between 100% SW grip distance and 200% SW grip distance is statistically significant,but it is notstatistically significant when 150% SW grip distance and 200% SW grip distance.4.There is a significant difference in IEGGMVC% with the change of the grip distance under the load of 30% 1RM,50% 1RM,70% 1RM(P <0.05),but there is no significant difference between different grip distances under 90% 1RM load Sex difference(P> 0.05).5.There is no significant difference in the IEGGMVC% of the pectoralis major at 100% SW,150% SW,200% SW(P> 0.05),and there is a significant difference between different loads(P <0.05).6.The difference between IEGGMVC% of the anterior deltoid muscle between 100% SW grip and 150% SW grip is-1.382(95% CI:-6.916 ~ 4.152),P = 1.000,which is not statistically significant.The difference between 100% SW grip distance and 200% SW grip distance was 3.512(95% CI:-3.172 ~ 10.196),P = 0.526,which was not statistically significant.The difference between the 150% SW grip distance and the 200% SW grip distance was 4.894(95% CI: 1.141 to 8.647),P = 0.010,which was statistically significant.Research conclusions: 1.As the grip length increases,the muscle contraction of the triceps,forearm flexors,and deltoid toe muscles has the greatest impact.The triceps and deltoid toe muscles increase with the grip distance.The contraction of the wide muscles weakens,and the muscle contraction of the biceps muscles increases as the grip length widens.The contraction of the pectoralis major muscle does not have much effect on the change of grip length.2.With 30% 1RM,50% 1RM,70% 1RM,the muscle contraction is enhanced with the change of grip distance,but the muscle contraction of 90% 1RM and 70% 1RM is not much different.At 90% 1RM,the muscle contraction of the head muscle does not change much as the grip length changes.3.In the flat bench press,the deltoid,pectoralis major,and triceps are the main muscles,and the anterior beam contraction of the pectoralis major and deltoid muscles is stable,and the biceps and forearm flexors play a smaller role,100% The recruitment rate of triceps muscle increased significantly with the increase of load at SW,and the recruitment of pectoralis major muscle increased significantly with the load at 150% SW.Through analysis and research,the following suggestions are obtained:1.It is best to choose a flat bench press with 100% SW grip for triceps exercises;150% SW or 200% SW is recommended for pectoralis major muscles.There will be too many anterior beams of the deltoid muscles for 100% SW work hard.It is recommended to use 100% SW grip distance for training the anterior beam of deltoid muscle.2.It is recommended to use a narrow grip with moderate load for triceps exercise.The load should not be too large.30% 1RM--70% 1RM is suitable.3.If we want to improve the strength of the flat bench press,we must pay attention to the training of the triceps,pectoralis major,and deltoid anterior beam.At the same time,we must not ignore the training of the flexors of the forearm and biceps.