Journal of Advanced Sport Technology
Volume:6 Issue: 1, Winter-Spring 2022

This paper presents an electronic training instrument for taekwondo athletes. The proposed prototype was inspired by the electronic body protector (EBP) used in previous Olympic games. Besides counting points, our prototype measures the energy of each strike, providing information to coaches about every strike's force and location in real-time. The prototype consists of a transmitter module installed inside a chest protector, a receptor module, and a human-machine interface (HMI). The proposed prototype aims to provide coaches and athletes with a tool for monitoring and improving the taekwondo technique.

This study aims to compare the dynamic parameters of professional elite volleyball players when landing from different heights. 15 volleyball players selected based on availability participated in the study. The studied skill for different height was set to a percentage of the maximum jump elevation (100% - 75% - 50%). A repeated measures ANOVA model was used to determine the measurements variance differences using SPSS software version 24. The results showed that landing from higher height increased the angular velocity of the rotational axis of the foot while the peak of angular acceleration was lower at the highest elevation. The linear velocity peak also showed lower values at the highest elevation, while the linear acceleration increased with increasing landing elevation. Despite the insignificant effect of different height on the vertical ground reaction force (vGRF) factor, the peak of ankle joint torque in the anterior-posterior axis increased with increasing elevation. Similarly, the maximum ankle angle in the anterior-posterior axis was higher at high elevation than at low elevation. The results showed that volleyball players try to improve the absorption of energy by increasing the range of motion of the ankle joint in the anterior-posterior axis at high elevation.

Sitting balance is essential for functional daily activities with certain significance for patients with spinal cord injuries (SCI). Assessment of sitting balance determines the individual's ability to control posture. Independence in daily activities requires appropriate stability in all movement plates. However, no testing protocol or tools have been developed to quantify sitting balance in all reaching directions. Thus, this study aimed to develop a comprehensive sitting balance test and determine the reliability, and validity of the Sitting Star Excursion Balance Test (SSEBT) for this population. 101 patients with chronic SCI participated voluntarily. To examine the reliability and validity of SSEBT, Pearson's correlation coefficient and the interclass correlation coefficient were used at a significant level of p <0.01. The SSEBT was highly correlated with the Modified Functional Test (r = 0.84), indicating the concurrent validity between the two tests. The inter Intra-class Correlation Coefficient was above 0.90, also the Inter-Class Correlation Coefficient for SSEBT was higher than 0.90. The results of this study revealed that SSEBT has good validity and reliability to measure the sitting balance in patients with spinal cord injuries. Therefore, this novel test is recommended for the measurement of sitting balance in this population.Keywords: Sitting Balance, Spinal Cord Injury, Postural Stability, Psychometric

Ball sports are used for various purposes among athletes. Volleyball is one of the most popular sports which very limited during the outbreak of Corona virus. Therefore, the purpose of this study was to design a new anti microb and virus Volleyball ball. The present study was done in order to design and manufacture new Volleyball ball to prevent microbes and virus distribution among Volleyball athletes. Initially, in order to design and produce a new antimicrobial Volleyball ball to prevent germs and viruses among Volleyball athletes, using rubber, it was combined with the material of sports balls such as titanium oxide, paraffin, and etc in the Nider machine. The obtained rubber material was transferred to the rubber baking machine for making the first layer of the ball. Then, in order to maintain the spherical shape of the first layer of the new Volleyball ball, we covered it with thread. To form the third layer of the new ball and to increase its bounce, a special fabric was used instead of rubber. Finally, we used special leather foam to form the last layer of the new ball. In the latex machine, we covered it twice with glue in order to better adhesion of the foam to the third layer. For the first time in the ball industry, this study investigated the antimicrobial ability of nano-silver against microorganisms .Based on previous research that examined the antimicrobial properties of nano-silver against microbes in various industries , it can be suggested that the use of nano-silver in the ball industry could be useful in eradicating a variety of microbes and viruses.

The aim of this study was to compare the dynamic model of torque and angular velocity in four methods of performing the Judan Mai-Mawashi-Geri technique by elite male karatekas. Eighteen elite male kumite practitioners participated in this study with mean and standard deviation age of 24.1±3.5 years, height of 176.2±4.6 cm, and weight of 73.7±6.5 kg. They had 2.5±1.98 years of experience in the national karate team and 2.8±1 years of experience in Iran’s Karate Super League. Six markers were attached to the anatomical points of the hitting foot. Three Hero3 cameras at a speed of 240 frames per second were used for collecting data about four methods of performing the Judan Mai-Mawashi-Geri technique. SkillSpector (version: 1.3.2) was used to obtain the joint coordinates (XY) and MATLAB was used to build the model. The one-way analysis of variance and the Bonferroni post-hoc test (p≤0.05) were used for statistical analysis after ensuring the normality of data distribution. The results showed a significant difference in the maximum torque and maximum angular velocity of the pelvic, knee, and ankle joints in the four methods of performing the Judan Mai-Mawashi-Geri technique. According to the results of the study, while emphasizing the sequential order of torque of the proximal to distal limb joints, we recommend the third method of performing the Judan Mai-Mawashi-Geri technique for an optimal and powerful implementation of this skill since the angular velocity of the knee joint is directly related to the peak velocity of the foot.

The main purpose of this study was to locate the public sport stations in Shahrood city by combining multi-criteria decision making methods in the Geographic Information System environment. The present study was practical and developmental in nature. It was also descriptive-analytical in terms of method. The method was based on the decomposition, locating public sport stations in Shahrood, and analyzing and overlapping information layers using the combination of multi criteria decision making including best-worst method and technique for order preference by similarity to ideal solution in the geographic information system environment. The present study was conducted in four stages. According to the experts' opinions in this study, attractiveness and environmental conditions were selected as the most important criterion and the potential for interference as the least important criterion. The calculated values for the stations also showed that Bolvar, Baharestan, Abshar, Shahrak Alborz and Shohada Mehrab parks are considered as top priorities and other parks as lower priorities for public sport in Shahrood, respectively. Using the results of this study, it can be stated that the officials and those involved have a clear and concise plan through which they will make fewer mistakes. According to the findings of the present study, it was suggested that the attractiveness index and environmental conditions of public sports stations be paid more attention and that the items that are not of high importance be given the last priority.

Depending on the type of application, smart textiles have special capabilities such as controlling one's physical condition and health, as well as recording and sending vital signs of the body. In sports activities, smart clothing can monitor the amount and type of athlete's activity, speed of movement, and control and report joint movements. These smart textiles can improve athletic performance by correcting movements and thereby preventing or reducing sports injuries. In this regard, a smart knee brace can be a useful tool to assist in lower-risk performance and prevent the athlete from putting their knee joint at risk. In this project, the researcher intends to take the first step in making this knee brace. The first step is to build a knee brace that can receive feedback from the knee flexion angle. For this purpose, the smart knee brace is designed from three components: signal processor, length-sensitive textile, and information processing software. Analog data obtained from a non-wavelength sensitive signal processor is converted to digital data, connected to the router via wireless chip, and received via Wi-Fi. The TCP Telnet Terminal application installed on the mobile phone is also used to view the data. To check the numbers recorded by the knee, the smart fabric was first rested and stretched, and the numbers recorded. Then the speed of pulling and turning of the fabric was evaluated, and at the end, the knees were positioned at different angles, and the numbers were recorded.

Measurement of the medial longitudinal arch (MLA) of the foot is a controversial issue in orthopedics. Using footprint parameters is considered as the most common method to evaluate MLA. Present study aimed to determine validity of footprint indices in measuring medial longitudinal arch in comparison with radiography method. Forty-one subjects were randomly selected. Footprints were recorded in static bipedal standing position using ink and paper. Arch index, footprint index, Chippaux-Smirak index, and Staheli index were calculated from the footprints. Also, calcaneal inclination, calcaneal-first metatarsal, talo-calcaneal angles and navicular height were obtained from lateral feet radiographs as a golden standard method for evaluating the static posture of the foot. All measurements of footprints and radiographs were calculated by a technique in computerized image analysis based on Adobe Photoshop software. Pearson correlation coefficient was used to determine validation. Results showed a strong relationship between the values of footprint indices and calcaneal inclination angle, calcaneal-first metatarsal angle and talo-calcaneal angle obtained from radiography (r=0.56 to 0.72). The highest correlation coefficient (r = 0.72) was observed between Staheli index and calcaneal inclination angle and the lowest correlation coefficient (r=0.56) was between the arch index and calcaneal inclination angle whereas no significant relationship was found between footprint indices and navicular height obtained from radiography. Analysis of footprint indices had an acceptable validity in measuring the medial longitudinal arch. Therefore, this method is recommended to be used as a valid, non-invasive, quick, cost-effective and accurate method for measuring MLA.

The purpose of designing and manufacturing a dual-purpose push-up and mechanical triceps device is to increase the strength of the arm and chest muscles without pressing on the lumbar vertebrae and creating lordosis. It works when an sportsman sits over themachine and fastens the belt. So that the person can adjust the amount of pressure applied to the muscles  by increasing or decreasing the upper and lower weights. Push-up is a common exercise which strengthens the central and upper body muscles. The central muscles are the muscles that control the spine, abdomen, back and lower back. This common exercise is present in many people's everyday workout program. Regular and daily practice of this exercise can increase muscle mass and physical strength and improve cardiovascular health. The central muscles of the body and legs are also involved in this exercise, although arm’s muscles and shoulders are used.  Therefore, push-up is useful for increasing the strength of all parts of the body. Designing a dual-purpose device for strengthening pectoralis major and triceps muscles can create a safe environment for performing this exercise.

The study of muscle synergy is a new method to evaluate the function of the control system of the human body. Due to the physical demands of the nature of triathletes it appears that triathletes are affected by variety degrees of muscle fatigue. The aim of this study was to determine the effect of fatigue on lower limb muscles synergy in novice triathletes. Sixteen male novice triathletes participated in this semi-experimental study. Electromyography activity of rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinosus, gastrocnemius medial, soleus and tibialis anterior muscles were recorded before and after the cycling-induced fatigue protocol during running task. Non-negative matrix analysis algorithm approach was used to extract muscle synergies from electromyography signals. Pearson correlation method was emplyoed to measure the similarity of the extracted patterns. Paired-sample t-test was employed to compare the relative weight of muscles before and after the fatigue protocol (P<0.05). After muscle fatigue, the first and second synergy patterns showed high similarity and the third and fourth synergy patterns showed moderate similarity. The relative weight of vastus lateralis muscle (P=0.012) and tibialis anterior (P=0.024) decreased significantly after muscle fatigue. The relative weight of semitendinosus (P=0.016) and soleus (P=0.031) muscles increased significantly after muscle fatigue. The number of four muscle synergies were obtained by variance accounted for method from electromyography activity data of muscles before and after muscle fatigue. Cycling-induced fatigue can affect the organized cooperation of the central nervous system to create synergy patterns in triathletes during running. It seems that disruption of synergy patterns and relative weight of lower limb muscles due to cycling-induced fatigue can change the mechanics of subsequent running in triathletes and increase the possibility of injury among these individuals.