The improvement of suspension training for trunk muscle power in Sanda athletes

Correlation analysis between biomechanical characteristics of taekwondo double roundhouse kick and effective scoring of electronic body protector

Objective: To explore the inherent relationship between lower limb biomechanical indicators and effective scoring values of double roundhouse kick (DRK) by taekwondo athletes, and to find key biomechanical factors that trigger effective scoring. Methods: Using the DAEDO Protector and Scoring System (PSS) in conjunction with the Vicon optical motion capture system and Kistler 3D force plate, kinematic and dynamic indicators of the front kicking motion were obtained from 12 professional taekwondo athletes (18.00 ± 2.20 years, 182.15 ± 8.62 cm and 70.00 ± 14.82 kg). The correlation between kinematics, dynamics, and scoring values was initially analyzed using bivariate linear correlation. Subsequently, based on the results of the linear correlation analysis, a stepwise regression analysis was performed to establish a stepwise regression equation. Results: The results reveal that during the First Hit, there is a significant positive correlation (r > 0, p < 0.05) between peak hip flexion angular velocity of the dominant leg, knee abduction angle, and peak foot horizontal plane linear velocity of the non-dominant leg with effective score. On the other hand, peak ankle flexion angular velocity of the non-dominant leg, peak foot sagittal plane linear velocity, peak hip abduction angle, and peak hip flexion angle of the dominant leg exhibit a significant negative correlation (r < 0, p < 0.05) with effective score. These correlations hold statistical significance (DW> 1.023). During the Second Hit, there is a significant positive correlation (r > 0, p < 0.05) between peak ankle internal rotation angular velocity of the dominant leg, foot coronal plane linear velocity, hip adduction angular velocity, and peak ankle internal rotation moment of the non-dominant leg with effective score. Conversely, peak hip flexion angle of the dominant leg shows a significant negative correlation (r < 0, p < 0.05) with effective score. All these variables have a statistically significant impact on effective score (DW > 1.023). Conclusion: Explosive power, body posture, adequate terminal velocity, and body rotation have an association with effective scoring of the electronic protector. The peak angular velocity of the ankle joint of the dominant leg and the peak linear velocity of the foot horizontal plane of the non-dominant leg significantly contribute to the effectiveness score of the electronic protector.

Biomechanics research on laterality effect between dominant and non-dominant during double roundhouse kick in the competitive taekwondo

Background

The Double Roundhouse Kick (DRK) is one of the major scoring tools and athletes employ the leg of the dominant side (DS) or the non-dominant side (NS) for always attacking in an alternating state. The purpose is to examine the discrepancies in the biomechanical characteristics of the DS and NS of the leg of the DRK skills of sub-elite taekwondo athletes.

Methods

Using the Vicon, Kistler, and Daedo brand Electronic Body Protector (EBP), collection of the DRK data (attack time, joint angle, joint angular velocity, joint moment, ground reaction force, etc.) of 12 sub-elite taekwondo athletes (19.6 ± 2.0 yr, 180 ± 7.3 cm, 70 ± 9.8 kg) with the DS leg and NS leg. The measured data analyses via Visual3D, and statistical methods using nonparametric tests paired with samples based on the Wilcoxon signed-rank test (The significance level is set as significant for P<0.05, and very significant for P<0.01).

Results

(i) There is no statistically significant discrepancy between the DS and NS at the time of hit (P>0.05) and shift of the center of gravity (P>0.05). (ii) Attacking leg (AL): the maximum knee flexion angle (Knee-MFA) (P<0.05) and the peak linear velocity of attack of the foot in the vertical hitting direction (P<0.01) on the DS was greater than that on the NS during the first hit phase (P1). (iii) Supporting leg (SL): the peak hip extension moment (P<0.05) on the DS was reported to be higher than that of the NS during the second hit phase (P2). (iv) Symmetry Index (SI): In the P1, the vertical ground reaction force (vGRF) of the SL leads to SI = 10.19 %, and in the P2, the vGRF of the SL results in SI = 18.48 %.

Conclusions

The DRK requires more and more symmetry between the DS and NS. The Knee-MFA of the AL and the line of attack speed of the foot in the vertical striking direction of the SL exhibited significant discrepancies. The DS has higher striking speed, athletes need to improve the striking speed of the NS leg in training, achieving more scoring opportunities in the game. Both the DS and NS revealed strong symmetry in the peak SI of the ground reaction force of the SL stirrup; however, weak symmetry was attained in the peak SI of the vGRF of the SL landing cushion.

Data collection of safety accidents in sports training of athletes with Internet of Things technology

The Internet of Things (IoT) technology is an information technology developed in recent years with the development of electronic sensors, intelligence, network transmission and control technologies. This is the third revolution in the development of information technology. This article aims to study the algorithm of the Internet of Things technology, through the investigation of the hazards of athletes’ sports training, scientifically and rationally use the Internet of Things technology to collect data on safety accidents in athletes’ sports training, thereby reducing the risk of athletes’ sports training and making athletes better. In this article, the methods of literature research, analysis and condensing, questionnaire survey, theory and experiment combination, etc., investigate the safety accident data collection of the Internet of Things technology in athletes’ sports training, and provide certain theories and methods for future in-depth research practice basis. The experimental results in this article show that 82% of athletes who are surveyed under the Internet of Things technology will have partial injuries during training, reducing the risk of safety accidents in athletes’ sports training, and better enabling Chinese athletes to achieve a consistent level of competition and performance through a virtuous cycle of development.

Acute Responses of Core Muscle Activity during Bridge Exercises on the Floor vs. the Suspension System

This study aimed to compare the neuromuscular activation of selected core musculature in supine and prone bridge exercises under stable versus suspended conditions. Forty-three healthy male participants were recruited to measure the electromyographic activities of the rectus abdominis (RA), lumbar multifidus (LM), thoracic erector spinae (TES), rectus femoris (RF), gluteus maximus (GM), and biceps femoris (BF) during supine and prone bridge exercises under six conditions: control, both arms and feet on the floor (Prone_con and Supine_con); arms on the floor and feet on the suspension system (Prone-Feet_suspension and Supine-Feet_suspension); and arms on the suspension system and feet on the floor (Prone-Arm_suspension and Supine-Arm_suspension). Prone-Arm_suspension yielded significantly higher activities in the RA, RF, TES, and LM than Prone-Feet_suspension (p < 0.01) and Prone_con (p < 0.001). Moreover, Supine-Feet_suspension elicited significantly higher activities in the RA, RF, TES, LM, and BF than Supine-Arm_suspension (p < 0.01) and Supine_con (p < 0.001). Furthermore, Supine-Feet_suspension elicited significantly higher activities in the RF, TES, and BF than Supine_con (p < 0.01). Therefore, if the RA and/or RF were the target training muscles, then Prone-Arm_suspension was recommended. However, if the TES, LM, and/or BF were the target training muscles, then Supine-Feet_suspension was recommended.

Efficacy of whole-body suspension training on enhancing functional movement abilities following a supervised or home-based training program

BACKGROUND

The purpose of this study was to determine the effects of suspension training on functional movement and body composition, and to compare the effectiveness of home-based training to supervised training.

METHODS

Seventeen healthy subjects (8 males, 9 females, age=21.8±3.4 y) with no recent history of resistance training were randomly assigned to a home-based or supervised training group. Subjects performed an 8-week suspension training program consisting of 10 exercises targeting major muscle groups, twice per week for the duration of the study. Pre- and post-intervention testing included body composition using air displacement plethysmography, and a functional movement screen (FMS) to measure functional movement abilities.

RESULTS

The 8-week training program significantly improved total FMS scores across the whole sample of subjects (Pre=16.4; Post=17.5; P=0.004), with no differences in improvements between groups. When compared separately, only the supervised group significantly improved FMS scores. There was also a significant increase in lean mass across the total sample of subjects (Pre=52.4 kg; Post=53.3 kg; P=0.03) with no differences between groups. But when compared independently, neither group exhibited a significant increase in lean mass.

CONCLUSIONS

When completed as a whole-body exercise program over an 8-week period, suspension training can improve functional ability and increase lean mass in both a supervised and a home-based setting.