The Relationship between Hand Grip Strength and the Accuracy of Field Tennis Services in Eighth Semester Male Students in Department of Training Faculty of Sports Science UNIMA

The aims of this study is to find out the relationship between hand grip strength and the accuracy of field tennis services. In this study the research method is quantitative research with independent variables Hand Grip Strength (X1), Sleeve Length (X2) and dependent variable Accuracy of Tennis Service (Y). The result show there is a significant relationship between hand grip strength and service accuracy in semester VII male students of the Department of Coaching Education. There is a meaningful relationship between arm length and correct service in 7th semester male students in Department of Coaching Education. There is a meaningful relationship between hand grip strength and arm length together with the accuracy of service to seventh semester male students of the Department of Training Education.


The Nature of the Strength of Hand Grips
The strength of the hand grip can be measured with a hand and grip dynamometer10 tool that is used to determine the strength of the hand muscles when grasping. A form of physical condition component that is useful for servicing. With good hand grip, tennis rackets can be held tightly without being detached when hitting the ball or receiving a hard ball. Training by using tools that can increase the strength of grip is very important to support sports activities. To enable achievement improvement, training must be guided by certain theories and training principles. Without doing routine exercises, it is impossible for athletes to obtain the expected achievements.
According to Bompa "exercise is a sporting activity which is carried out systematically over a long period of time and is progressively increased and individually leads to the characteristics of physiological and psychological functions to achieve the determined targets". Training has certain limitations, therefore we need to understand what the limits of the practice are. In simple terms the training limit according to Harsono: "Exercise is a systematic process of practicing that is done repeatedly with increasing days increasing the amount of training load".
Although the exercise is carried out repeatedly, systematically and increasingly adds to the burden, besides that the principle of exercise is also important as a guideline for anyone who wants to improve their sports performance. Exercise in principle puts physical pressure on the body regularly and systematically, continuously or continuously so that it will improve the ability of athletes' skills. And to carry out an exercise required appropriate training methods as a condition for achieving goals.
From the description above it can be concluded that training is a planned and systematic activity to prepare athletes from both physical and technical conditions to deal with pressure in comparison.

The Length of the Arm Essence
The arm is one of the organs of the human body that has an important role in sports activities especially in daily life. Arm length is a human body structure that can be measured from the shoulder (shoulder to shoulder) to the tip of the middle finger. By looking at human body movements, the arm can be divided into two parts, namely the upper arm and lower arm. According to Syaifuddin the muscles of the upper arm consist of: "the biceps brachulus, the brachial muscle, the brachial korako muscle, etc." While the muscles of the forearm consist of: m. extensor carpi radialis longus, m. extensor carpi radialis brevis, and m. ektensor karpi ulnaris, digitorium karpi radialis, m. extensor policis longus, etc.

Figure 1. Position of Measurement of Arm Length
As said by Evelin C. Pearce that: "The body frame with the shoulder bracelet consisting of clavicle and scapula, underneath there are bones that form the skeleton of the arm, forearm, palms totaling 30 pieces of bone".

III. Research Method
In this study the research variables are: 1. The independent variable: a. Hand Grip Strength (X1) b. Sleeve Length (X2) 2. Dependent variable: Accuracy of Tennis Service (Y) The strength of the hand grip is one component of the physical conditions needed in tennis. With a good hand grip, it will be easier for athletes to hold the racket firmly and create more efficient blows in relation to the use of the hand muscles. Exercise is very important to help improve the ability to do sports activities. To enable increased achievement, training must be guided by certain theories and training principles. Hand grip strength must be trained by providing training in a programmed and continuous or repetitive manner, this form of exercise is in the form of a hand grip device. For example by squeezing the tool with regular exercise. And using a dynamometer hand and grip measuring instrument with interval scale.
Someone's arm length is different from one another. Arm length is one of the supporting factors in athletes doing good service. And everything can be seen from someone's posture or even measured by the cm unit with an interval scale.
As has been explained that if the tennis player wants his opponent to be unable to return his service and earn points, then the strength of the hand grip and arm length and the accuracy of the service of the player must be properly trained, because if the player has it all will make it easier to get points from his opponent with service that is effective and efficient.
Service accuracy is the ability for someone to do the right service on target and is difficult for the opponent to reach. Accuracy is a very important component in playing tennis on the pitch to aim the ball at the target so that it can complicate the opponent's reach and can generate points without expending excessive energy. "And the ability to measure service accuracy can be measured by the number points specified in the service area or area". The time needed to collect research data is 1 (one) week at 14.00 -17.00 According to Arikunto, quoted by Sinaga: "If the subject or population is less than 100 people, all of them are taken so that the research is a population study. Whereas if the number of subjects is more than 100 people, it is taken between 10-15% or 20-25% or more ". How to take population and sample taken by using the formula and steps as follows:

Research Design
1. Population: are all semester VII male students of the FIK-UNIMA Coaching Education Department with 40 students. 2. Sample: is the total population of 40 people. Thus this study is a population study. The instruments of this research are: 1. The strength of the hand grip is used by the hand and grip dynamometer. 2. The length of the arm is used in meters cm.
3. Service accuracy is used in measuring meters with numbers designed by Hewit, et al in the book "Measurment concepts in Physical Education". Tools and Equipment -Tennis court -Tennis balls as much as 30 pcs -Tennis racket -Net -Chalk -meter gauge a. Service accuracy is measured by: Testi stands behind the service line and is ready to serve. Testi are given 10 (ten) service opportunities only in the right position then the service box is divided into six boxes and each box has its own value according to the difficulty level. Each ball that easily passes the net is scored according to the value indicated on the service target box. A ball that is not entered is given a value of 0. The service accuracy value of each child is the sum of values obtained from the 10 balls that are serviced. By Hewit

b. A hand grip test is taken by:
The male students stood up straight and relaxed then were given the opportunity to use the dynamometer hand and grip 2 (two) times.

c. The arm length test is measured by:
The male student stands, then the arms are stretched on the table and the arms are measured by a meter from the shoulder wrist to the tip of the middle finger. Data collection on hand grip strength, arm length and service accuracy were carried out in October 2013, with the following schedule:

Data Analysis Techniques
Hypothesis 1 and 2 analysis techniques use "Product Moment Correlation Analysis" as follows: Hypothesis 1 : rxy = To start the analysis, it is preceded by a test of requirements, namely a test for normality and linearity.

• Testing Arm Length Normality Data
To find out whether the sample comes from a normally distributed population, then the data normality test is done with the test a). The first step: determine the testing hypothesis The testing hypothesis is: HO: Samples come from populations that are normally distributed Ha: Samples come from populations that are not normally distributed. b). Second step: Determine the testing criteria Testing criteria are: Thank Ho if Lo <Lt Reject Ho if Lo> Lt Significance rate α 0.05 c). Third step: calculate Zi, F (Zi), S (Zi) and the difference between F (Zi) -S (Zi) and input them into the table.
Dik : _ X 2 : 50.08 Sdx2 : 9.97 The product of this research is in the form of developing the steps of a problem based learning model so as to produce a problem based learning model with nine steps in learning to write an exposition text. The development of the learning steps is done by modifying the phases contained in the problem based learning model, as revealed by Hosnan (2014: 295) contained in table 7: Thus the conclusion of the test is that the study sample comes from a normally distributed population.

• Testing the Normality of Service Accuracy Data
To find out if the sample comes from a normally distributed population, then the data normality test is done with the lilliefors test. Data normality testing is carried out with the following steps: a. The first step: determine the testing hypothesis The testing hypothesis is: HO: Samples come from populations that are normally distributed HA: Samples come from populations that are not normally distributed. b. Furthermore, to test and prove the hypothesis that has been proposed can be used moment correlation Products test statistics for the first hypothesis (X1 analysis with Y or the relationship between hand grip strength with service accuracy) and the second hypothesis (X¬2 analysis with Y or the relationship between arm length with service accuracy). While the multiple correlation test statistics are used to test the third hypothesis (X1, and X2 analysis with Y or the relationship between hand grip strength and arm length with service accuracy).

2). Research Hypothesis Testing The Relationship Between Hand Grip Strength and Service Accuracy (Correlation Analysis X1 to Y).
To test whether there is a relationship between hand grip strength (X1) and service accuracy (Y) that is done by calculating r (correlation) through the formula: The calculation results of the analysis of the relationship X1 with Y or between the strength of the hand grip with service accuracy, obtained the magnitude of the correlation coefficient (r) = 0.70, based on the interpretation table correlation coefficient r value this shows the level of a strong relationship between the strength of the hand grip with service accuracy. Furthermore, to state the size of the contribution of the variable X1 to Y can be determined by the formula of the determinant coefficient as follows: KP = r2 x 100% = 0.702 x 100% = 49%. Thus the magnitude of the contribution of hand grip strength to service accuracy is 49% and the remaining 51% is determined by other variables.

3). Research Hypothesis Testing Relationship Between Arm Length With Service Accuracy (Correlation Analysis X2 with Y)
 n X1 X2 Y  X1 2  X2 2  Y 2 X1Y X2Y X1X2 The calculation results of the analysis of the relationship X2 with Y or between the length of the arm with service accuracy, obtained the magnitude of the correlation coefficient = 0.65, based on the interpretation of the correlation coefficient table r values this shows the level of a strong relationship between arm length with service accuracy. Furthermore, to state the size of the contribution of the variable X2 to Y can be determined by the formula of the determinant coefficient as follows: KP = r2 x 100% = 0.652 x 100% = 42.25%. Thus the magnitude of the contribution of the variable arm length with service accuracy is 42.25% and the remaining 57.75% is determined by other variables.

4). Research Hypothesis Testing Relationship between the Strength of Hand Grips with Arm Length (Correlation Analysis X1 to X2).
To find out the magnitude of the relationship between X1 and X2, using the following formula: The results of the analysis of the relationship between X1 and X2 or between the strength of the hand grip with the length of the arm, obtained the magnitude of the correlation coefficient = 0.55. Based on the interpretation table correlation coefficient r value this shows the level of a fairly strong relationship between the strength of the hand grip with the length of the arm. Furthermore, to state the size of the contribution of the variable X1 to X2 can be determined by the formula of the determinant coefficient as follows: KP = r2 x 100% = 0.552 x 100% = 30.25%. Thus the magnitude of the contribution of the variable strength of the hand grip with the length of the arm is 30.25% and the remaining 77.91% is determined by other variables.

5). Multiple Correlation Analysis for X1 and X2 with Y
The hypothesis that will be tested in this study is the relationship between hand grip strength and arm length together with the accuracy of field tennis services for seventh semester male students of the Department of Training in the Faculty of Sport Science, UNIMA. So to test this hypothesis by using the multiple correlation formula (double correlation), followed by calculating the significance of the multiple correlations with the formula: Calculation of research hypothesis testing is carried out with the following steps: a. first step: determine the research hypothesis Research hypotheses are: Ho: there is no correlation between the strength of hand grip and arm length together with the accuracy of the tennis services of the eighth semester students of male students in the Department of Training in the Faculty of Sport Science, UNIMA. Ha: there is a correlation between the strength of hand grip and arm length together with the accuracy of the tennis services of the eighth semester students of the students of the Department of Training in the Faculty of Sport Science, UNIMA. b. Second step: determine the testing criteria.
Testing criteria are: Accept Ho if the observation rtable means that it is not significant Reject Ho if observation> r table means significant. Significance level 0.05 and known = n -k -1 = 40 -2 -1 = 37. Ftable = (dk = k), (dk = n -k -1) = (dk = 2), (dk = 40 -2 -1) = 2 and 37 The way to find Ftable is number 2 as a numerator and 37 as a denominator. Thus a Ftabel of 3,225 (Interpolation) was found. (Appendix 9) a. Third step: calculate Calculated through formulas: Before calculating Fcount then first look for it Rx1x2y or Multiple Correlation through the formula.  The simultaneous relationship between hand grip strength and arm length with the accuracy of the eighth semester student field tennis services of the Department of Sport Training of the Faculty of Sport Sciences UNIMA is relatively strong. The simultaneous contribution of variables X1 and X2 to Y = r2 x 100% = 0.772 x 100% = 59.29% and the remaining 40.71% is determined by other variables.
Next to test the significance of the proposed hypothesis through the formula: Step four: conclude the calculation results.
From the results of testing the research hypothesis obtained Fcount = 26.94 with a level of confidence 0.05 and dk = n -k -1 = 40 -2 -1 = 37, so it was found Ftable = 3.225. So Fcount is greater than F¬table, i.e. Fcount = 26.94> Ftable = 3.225. In accordance with the testing criteria if Fcount> Ftable then Ho is rejected, which means accept Ha or a hypothesis stating there is a correlation between the strength of hand grip and arm length together with the accuracy of field tennis services in the eighth semester students of the Department of Coaching Education at the Faculty of Sports, UNIMA.
Based on the test results described earlier it is proven that there is a significant relationship between the strength of hand grip and arm length together with the accuracy of the tennis services of the eighth semester male student tennis department of the Department of Training in the Faculty of Sport Science, UNIMA. The full description is as follows: 1. There is a Relationship between Hand Grip Strength (X1) with Service Accuracy (Y). Based on the results of testing analysis between the strength of the hand grip with service accuracy, the correlation coefficient (r) = 0.70, based on the interpretation coefficient table r correlation value shows that there is a strong relationship between hand grip strength and service accuracy. Furthermore, the contribution of hand grip strength to service accuracy is 49% and the remaining 51% is determined by other variables. 2. There is a Relationship between Arm Length (X2) and Service Accuracy (Y) Based on the calculation results of the analysis of the relationship X2 with Y or between the length of the arm with the accuracy of service, obtained the magnitude of the correlation coefficient = 0.65, based on the interpretation coefficient table correlation value of r this shows the level of a strong relationship between arm length with service accuracy. Furthermore, to state the size of the contribution of the X2 variable to Y or the arm length variable with service accuracy is 42.25% and the remaining 57.75% is determined by other variables.

There is a Simultaneous Relationship between the Strength of Hand Grips and Arm
Length with Accuracy in Field Tennis Services for 7 th Semester Male Students Department of Training in the Faculty of Sport Science UNIMA The simultaneous relationship between hand grip strength and arm length with accuracy of field tennis services for eighth semester students of the Department of Sport Training of the Faculty of Sport Science UNIMA is relatively strong, where a correlation r value of 0.77 is obtained. The simultaneous contribution of variables X1 and X2 to Y = r2 x 100% = 0.772 x 100% = 59.29% and the remaining 40.71% is determined by other variables.
The results of the calculation of the analysis of the relationship X1 and X2 together with (Y), showed the magnitude of Fcount = 26.94 with a level of confidence 0.05 and dk = n -k -1 = 40 -2 -1 = 37, so it was found Ftable = 3.225 . So Fcount is greater than F¬table, i.e. Fcount = 26.94> Ftable = 3.225. In accordance with the testing criteria if Fcount> Ftable then Ho is rejected, which means accept Ha or a hypothesis stating there is a correlation between the strength of hand grip and arm length together with the accuracy of field tennis services in the eighth semester students of the Department of Coaching Education at the Faculty of Sports, UNIMA.
The results of the discussion above show that the strength of the hand grip and arm length are very important in determining the accuracy of field tennis services for seventh semester male students of the Department of Training in the Faculty of Sport Science, UNIMA. Students who have the strength of hand grip and arm length in servicing in playing tennis will be better prepared and easier to do service accuracy. Thus the conclusion in this study is that there is a significant relationship between the strength of hand grip and arm length together with the accuracy of field tennis services for seventh semester male students at the Department of Coaching Education at the Faculty of Sport Science, UNIMA.

V. Conclusion
There is a significant relationship between hand grip strength and service accuracy in semester VII male students of the Department of Coaching Education. There is a meaningful relationship between arm length and correct service in 7 th semester male students in Department of Coaching Education. There is a meaningful relationship between hand grip strength and arm length together with the accuracy of service to seventh semester male students of the Department of Training Education.