The relationship between limb length and flexibility with the speed of martial arts side kicks

The problem delivered in this study is that some fighters are easily caught when performing side kicks, need help attacking rivals with a higher posture, and need to reach the optimal point when performing splits. This study aims to determine the correlation between leg length and flexibility with the speed of side kicks in martial arts. This quantitative research defines the correlation between the independent and dependent variables. This research uses sampling of 30 fighters by utilizing purposive sampling. The research instrument for limb length uses a rolling meter and flexibility using a side split test, while a statistical test uses multiple correlations. The results showed that (1) there was no significant correlation between leg length and sidekick speed with a sig. of 0.621; (2) There is a significant correlation between flexibility with sidekick speed and the sig value of 0.002;(3) There is a significant correlation between leg length and flexibility with sidekick speed, with an r-value of 0.007. This study concludes that anthropometric components are needed to do side kicks quickly and well in martial arts, especially leg length and physical condition aspects of flexibility.


Introduction
Martial arts are popular and widely spread in various regions in Indonesia.Martial arts is a selfdefense system passed down from our ancestors as the culture of the Indonesian people, so it needs to be preserved, nurtured, and developed (Kriswanto, 2015;Purnamasari et al., 2020;Utami & Kafrawi, 2014).In its development, martial arts have many variations and consists of various martial arts schools.
There are various martial arts schools in Brebes Regency, such as Setia Hati, Tapak Suci, Perisai Diri, Padjadjaran Nasional, Pagar Nusa, Personas Azad, and Indonesia Seni Bela Diri (INSEBA).INSEBA in Brebes Regency is developing in the North Brebes area, which is widely spread at the school level for its achievements and regeneration.INSEBA schools actively participate in martial arts championships organized by IPSI at the regional, provincial, and national levels.Achievements received from INSEBA Brebes Regency are the 2016 INSEBA CUP General Champion and the 2017 Brebes Regency Regional Championship.
The basic techniques used in INSEBA are identical to the practices of martial arts in general.The methods used in martial arts matches use to attack and defend (Liskustyawati et al., 2019;Sudirjo & Rukmana, 2019).There are two types of attacks: hand attacks and leg and foot attacks-various kinds of hand attacks, such as punches, slashes, stabs, smacks, and tight.Various attacks use the feet and legs, such as kicks, sweeps, slashes, and kneeling (Yolanda et al., 2020).
According to, there are several types of kick techniques, such as front kicks, crescent kicks, side/T kicks, and back kicks.Kicks in the game and the sport of martial arts are included in attacks using the legs that target the rival's body.Kick is one of the basic martial arts techniques often used in a match.One kind of kick technique is the sidekick/T.A side kick is carried out with a straight kick trajectory to the side and a sideways body position to form the letter (T).It is subject to kicks on the outside (Kriswanto, 2015).Side kicks target the whole body using the legs with a straight trajectory forward, with the body facing the impact side on the outside of the feet, soles of the feet, and heels (Lubis & Wardoyo, 2016).Kick is one of the big points and is often used in martial arts matches (Anugrah et al., 2022;Hariono et al., 2021).Kicks are also included in the arts category, both single and team.
Based on observations made by researchers at the INSEBA school in Brebes Regency, the following data can be presented: 1) There are 38 INSEBA blue belt fighters, 2) there are 20 fighters (52.6%) whom rivals quickly catch with below-average kicking abilities, specifically three challenging kicks to catch, 3) found that 15 fighters (39.5%) had shorter stature, so they found it challenging to attack fighters who had taller stature with an average height of 165 cm, 4) there were 17 fighters (44 .7%)with low splits performance (all legs do not touch the floor).The description of the athlete's performance condition will affect the athlete's achievement, especially in sidekick speed.
Leg length or tall posture has an essential role in the appearance of martial arts.Attacks using kicks have a higher value than attacks using punches.According to Hasan (2015), there is a significant correlation between leg length and sickle kick ability in martial arts.The research results show that body height, leg length, and power are related to the speed of martial arts side kicks (Harun et al., 2020;Khokhlova, 2021).
Correspondingly, flexibility is essential in performing martial arts in both the sparring and arts categories.Flexibility positively correlates significantly with sickle kick speed ability (Nusufi, 2015).The results of research from Syahri (2019) stated a significant effect between fighters with high and low flexibility on the speed of side kicks in martial arts.Based on the problems described, this study aims to determine the correlation between limb length and flexibility with sidekick speed in martial arts sports.

Research Design
The research method used in this research is quantitative, using a correlational approach.This research was conducted in September 2021 at the INSEBA Pencak Silat school, Brebes Regency.

Participants
The population used in this study were INSEBA martial arts fighters in Brebes Regency, totaling 192 fighters.The research sample consisted of 30 male athletes, with the sampling technique using purposive sampling.The purposive sampling technique is a technique for determining samples with particular criteria (Sugiyono, 2019).The inclusion criteria in determining the sample of this study are as follows: a. Male gender b.Level IV or blue belt c.Age 17-25 d.The minimum practice age is two years Criteria exclusion in determining the sample of this study, as follows: a.They are suffering from an injury.b.In the process of recovery, both illness, and injury

Instrument Test
The instruments used in this study include measuring leg length using a rolling meter, and the unit is centimeters (cm) from the groin to the toe in an upright standing position without using footwear.The leg length measurements will be processed using PAN (Norma Reference Assessment).The flexibility test used by the researchers was the side splits test conducting three trials, and the best results choose the point.This test has a validity of 0.753 and a reliability of 0.859 (Kuswanto, 2016).Test the speed of side kicks by performing as many sides kicks as quickly as possible for ten seconds using the right and left feet with a target height or sand sack for women 75 cm and men 100 cm (Lubis & Wardoyo, 2016).Data collection was carried out on the right leg and three times on the left leg.The best result is obtained from the chosen point.The data acquired will be from a combination of the results of the best sidekick speed of the right foot and the results of the best sidekick speed of the left foot.

Data Analysis
The analysis used in this study is the normality and linearity tests as prerequisite tests before testing the hypothesis.The data is stated to be normally distributed if the sig.> 0.05 linear if the sig.>0.05.The hypothesis test used in this study is the Pearson product-moment correlation test and the multiple correlation test.

Results and Discussion
Research data is processed using SPSS assistance regarding tests and measurements of leg length in martial arts athletes are presented in table 1 below.Based on the data in the table 1 for calculating leg length using PAN shows, there are three fighters in the excellent category, three athletes in the good category, 16 in the moderate category, six in the low category, and two athletes in the deficient category.Next, the flexibility test results obtained by martial arts athletes can be seen in table 2 below.From the data in the table 2, the results of the calculation of flexibility show that there are three fighters in the excellent category, four in the good category, 16 in the moderate category, 5 in the low category, and two in the deficient category.The results of the martial arts sidekick speed test are shown in table 3 below.The data from the sidekick speed calculation results (Table 3) show three fighters in the excellent category, seven in the good category, 12 in the moderate category, four in the low category, and four in the deficient category.

Data Normality Test
The  4, it is known that each variable shows a significant value that is obtained more than 0.05 (sig.> 0.05), and it can be concluded that all data is typically distributed.

Data Linearity Test
The linearity test was carried out to determine whether the independent variable data has a linear relationship with the dependent variable.The data linearity test results from leg length, flexibility, and INSEBA side kick speed in Brebes Regency, are shown in table 5 below.

Correlation Test
Multiple correlation tests were conducted to determine whether there is a reciprocal relationship between leg length and flexibility variables with side kick speed variables.Decision making if the significance value is less than 0.05 (sig.<0.05), then it can be concluded that the leg length and flexibility variables with the side kick speed variable have a significant relationship and vice versa.The results of the correlation test are shown in table 6 below.Based on the correlation analysis results, a significance value of leg length of 0.621 (sig.0.621 > 0.05) was obtained, which means there is no relationship between leg length and the speed of martial arts side kicks.Meanwhile, the significant value in flexibility is 0.002 (sig.0.002 <0.05), meaning that flexibility has a significant relationship with the speed of the martial arts sidekick.The results of multiple correlations can be seen in table 7 below.Based on the results of the correlation analysis, a significance value of 0.007 (sig.0.007 <0.05) was obtained, which means that there is a significant relationship between leg length and flexibility variables with side kick speed variables.The coefficient r value of 0.557 has a moderate level of correlation.
The analysis of the data obtained from the correlation of leg length with sidekick speed showed no correlation between correlation e two.This research is supported based on the results of previous research that a study conducted by Yudha (2019) stated that there was no relationship between leg length and crescent kick speed.The contribution of leg length to sickle kick speed is only 2.98%.Line with research from Hassan (2015) shows the results of the correlation analysis of leg length with sickle kick speed of 0.173, including a deficient correlation level with an S.E.value of 0.030.This result means that the effective contribution made by leg length to sickle kick speed is 3%.
The factor causing the absence of a correlation between leg length and the speed of martial arts side kicks is body balance.Motion is a change in the position of an object from the initial balance point (Kusuma et al., 2019;Umar & Utama, 2018).Some fighters are unbalanced when performing side kicks, so they need time to balance their bodies before continuing the next move.Performance in sports often depends on a person's ability to maintain body balance periodically, shift body weight to gain stability, and make movements (Sharma, 2015;Wirasasmita, 2014).
In martial arts, the speed of kicks cannot be determined merely from the length of the legs, but other aspects must support it.Results of research, leg length and height will correlate with the ability to kick the martial arts sickle if it is influenced by eye-foot coordination and speed (Subekti, 2014).The practical contribution was only 8.09% less than eye-foot coordination of 35.11% and speed of 24.06%.Research by Harun et al. (2020) suggested that two athletes with the same leg length have different sidekick speed abilities because they have additional power.
In addition, the lack of energy can also be one of the reasons there is no correlation between leg length and the speed of martial arts side kicks.Quick side kicks are an anaerobic activity.Muscle contraction can only occur when there is a potential source of ATP in the muscle (Giriwijoyo & Sidik, 2012).The intramuscular reserve of ATP is relatively small (5 mmol/kg), which is depleted within seconds with maximal exertion.The fighter carrying out the test takes ten seconds with a maximum speed capability of only a few seconds, and the rest will experience a decrease in kick speed.All other resources, such as ADP, carbohydrates, fats, The results of data analysis related to the correlation between flexibility and the speed of martial arts side kicks show a significant relationship.Athletes with a good level of flexibility can perform various movements in sports to the fullest, including kicks in martial arts.

Conslusions
There is no significant relationship between leg length and sidekick speed at the INSEBA martial arts school in Brebes Regency.There is a significant correlation between flexibility and sidekick speed at the INSEBA martial arts school in Brebes Regency.The aspect of flexibility has a more significant impact on supporting sidekick speed in martial arts athletes than leg length.
Recommendations for future research can review related aspects of leg length in martial arts t kicks by paying attention to various aspects, such as balance factors, more accurate test execution, and physical and psychological conditions of athletes.It can also examine training methods that can improve aspects of kick speed in martial arts athletes.

Table 1 .
Results of the Martial Arts Athlete's Leg Length Test No.

Table 2 .
Results of the Flexibility Test for Martial Arts AthletesNo.

Table 3 .
Results of the Martial Arts Side Kick Speed Test No.
results of the data normality test of leg length, flexibility, and sidekick speed of the INSEBA athlete in Brebes Regency are presented in table 4 below.
Based on the results of the data normality test analysis in table

Table 5
Based on the table 5 regarding the results of the linearity test, the significance value is more significant than 0.05.Based on data analysis from the linearity test, it can be concluded that leg length and flexibility have a linear relationship with sidekick speed in INSEBA martial arts athletes in Brebes Regency.

Table 6 .
Correlation Test of Leg Length and Flexibility with Side Kick Speed of Martial Arts Athletes

Table 7 .
Multiple Correlation Test Results