Estimation of Handgrip Strength and its Correlations with Selected Anthropometric Variables and Performance Tests in Indian Interuniversity Female Field Hockey Players

Grip strength is often used as an indicator of overall physical strength [1,2], hand and forearm muscles performances [3] and as a functional index of nutritional status [4,5], physical performance [6,7]. The power of handgrip is the result of forceful fl exion of all fi nger joints with the maximum voluntary force that the subject is able to exert under normal biokinetic conditions [8,9], which uses several muscles in the hand and the forearm [10].


Introduction
Grip strength is often used as an indicator of overall physical strength [1,2], hand and forearm muscles performances [3] and as a functional index of nutritional status [4,5], physical performance [6,7]. The power of handgrip is the result of forceful fl exion of all fi nger joints with the maximum voluntary force that the subject is able to exert under normal biokinetic conditions [8,9], which uses several muscles in the hand and the forearm [10].
Handgrip strength is a physiological variable that is affected by a number of factors including age, gender and body size. Strong correlations between grip strength and various anthropometric traits, (weight, height, hand length etc.) were reported earlier [11][12][13][14][15][16][17][18]. Effect of socio-economic status on handgrip strength were studied by Henneberg et al [19].
Field hockey is an intermittent endurance sport involving short sprinting as well as movement with and without ball [20]. Successful performance in fi eld hockey is infl uenced by morphological and anthropometric characteristics such as body size and composition, functional parameters (physical capacity) [13,[21][22][23][24][25][26], and fi tness (explosive strength, maximum speed,

Sit and reach test
Sit and reach test was used to estimate back and hamstring

Vertical jump test
The subject was asked for warm up with several easy jumps proceeded with a few minutes rest, which also served the purpose of reviewing the jumping technique of the subject.
The subject was told to bend the knees immediately prior to the jump (countermovement technique) which activated the stretch-shortening cycle in the muscles, resulting in greater power production in the legs. While resting, the subject was asked to stand with side toward wall and reach up as high as possible keeping the feet fl at on the ground to mark the standing reach height. As and when the subject was ready, with colour on the distal part of his/her third fi nger (of right hand), he/ she was asked to jump up as high as possible using both arms and legs to assist in projecting the body upwards and touch the wall at the highest point of the jump. The subject performed multiple attempts with short rests until a plateau or decrease in performance was observed and the best score was recorded in cms. The "net height" was calculated by subtracting the standing reach height from the jump height in cm.

Statistical analysis
Standard descriptive statistics (mean ± standard deviation) were determined for directly measured and derived variables.
One way analysis of variance was tested for the comparisons of data among Indian inter-university female fi eld hockey players playing position-wise (goal keepers, defenders and strikers), followed by post hoc Bonferroni test. Pearson's correlation coeffi cients were applied to establish the relationships among the variables measured. Data were analyzed using SPSS (Statistical Package for Social Science) version 20.0. A 5% level of probability was used to indicate statistical signifi cance.

Results
Descriptive statistics of handgrip strength, selected anthropometric variables and performance tests in Indian inter-university female fi eld hockey players were shown in Table 1. One way analysis of variance showed statistically no anaerobic and aerobic capacity), agility [27][28][29][30]. Information related to the handgrip strength and its correlations with anthropometric variables and performance tests in female hockey players are limited, especially in Indian context. So the present study was planned.

Participants
The present cross-sectional study was based on purposely selected 121 Indian inter-university female hockey players

Handgrip strength measurement
The grip strength of both right and left hands was measured using a standard adjustable digital handgrip dynamometer

Discussion
Hockey is a short-distance sport where running means mostly sprinting, and the sprinting-distances vary from only a few meters to not more than 50 or 60 meters. Therefore, quickness, explosive strength and agility are the characteristics that signifi cantly infl uence performance in the fi eld hockey. It is reported that a battery of anthropometric and morphological tests can distinguish between players of different ability in the same sport [33]. The same is true for the fi eld hockey [13,20,26,34,35]. As handgrip strength is considered as the total body strength [2], it is essential to estimate the handgrip strength of the female fi eld hockey players and to identify the factors affecting on this trait.
In the present study, comparisons were made among goalkeepers, strikers and defenders of Indian inter-university female fi eld hockey players. One way analysis of variance showed no signifi cant differences in any case. It may be stated from the fi ndings that not much differences were there among position-wise Indian female fi eld hockey players, may be due to structural and physiological, as well as the training program affi nity among them. Signifi cantly positive correlations (p ≤ 0.05 -0.01) of dominant handgrip strength were found only with non-dominant handgrip strength in female fi eld hockey players. No other anthropometric variables had any association with handgrip strength, though statistically signifi cant correlations were found among the anthropometric variables themselves (which was obvious). The fi ndings of the present study did not follow the same line of the earlier fi ndings of Koley and Singh [15], Koley and Yadav [14] and Koley et al. [16], where they had found strong positive correlations of dominant right handgrip strength and selected anthropometric variables in various populations. The present data may differ from other studies may be due to gene pool and environmental factors including socio-economic status and nutrition of the female fi eld hockey players. The noble part of the this study was that, the position-wise analysis of the Indian female fi eld hockey players. Not many references are available in this regard, especially in Indian socio-cultural context. The limitations of the study were the small sample size and only female players. Age in which the athletes begin their sport activity should also have been included in the study, as handgrip strength depends upon the sport experience of the athletes. In the future study all these limitations will be taken into consideration.

Conclusion
It may be concluded from the present study that, though no signifi cant between-group differences were found in any of the anthropometric variables and performance tests, among these three sets of players, signifi cantly positive correlations (p ≤ 0.05) of handgrip strength were found only with nondominant handgrip strength. The data presented in the study carry immense practical applications and should be useful in future investigation on player selection, talent identifi cation in fi eld hockey and training program development.