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This paper aims to determine the relationship between the measures of shooting performance handgrip strength and weapon kinematics during different phases of the shot. The research included 35 part...

The aim of this paper was to provide a possible methodological solution for monitoring of the marksmanship training progress and evaluation of the level of shooting skill acquisition with service pistol CZ99. The second aim was the idea of development of a screening model for gender-dependent classification of the police personal, other security personnel and sport-oriented personnel in relation to their basic marksmanship skill. The research sample included a total of 83 participants (Men = 53, Women = 30) initially divided into four qualitative categories according to the personal shooting experience and shooting skill level. The applied principal component analysis has revealed a highly stable structure of the component matrix of the extracted factor. The following variables had the highest descriptive value in relation to the shooting skill in the respective samples regardless of distance: Men - an averaged value of the hit circles on the target and rounds fired, the index of efficiency considering precision and a coefficient of variation of hit circle achieved during the shooting at the target; Women - an averaged value of the hit circles on the target and rounds fired, the index of efficiency considering precision, a coefficient of variation of hit circle achieved during the shooting at the target and the index of efficiency considering accuracy. On the basis of the obtained results highly statistically significant (p ≤ 0.000) specific multidimensional models were developed which enabled statistically significant classification of the participants relative to the pistol shooting skill classification. The accuracy of the defined equation model for estimation of shooting skill score classification was 59.7 and 61.5% for men and 68.6 and 68.0% for women in relation to the examined shooting distances of 6 and 10 m, respectively.

The aims of this study were (1) to evaluate the shape of the load-velocity (L-V) and force-velocity (F-V) relationships obtained during the medicine ball throw (MBT) test, (2) to explore the reliability of their parameters (L-V parameters: maximal load ( L0), maximal velocity ( V0(L-V)), slope of the L-V relationship ( a(L-V)), and area under the L-V relationship line (Aline); F-V parameters: maximal force ( F0), maximal velocity ( V0(F-V)), slope of the F-V relationship ( a(F-V)), and maximal power ( Pmax)), (3) to explore the concurrent validity of the two-point with respect to the multiple-point method, and (4) to evaluate the external validity of L0 and F0 with respect to the maximal strength. Twelve males performed MBTs against four loads, a bench press 1-repetition maximum (1 RM), and maximal isometric medicine ball push. The L-V and F-V relationships were strongly linear (individual r ≥ 0.886). V0 was the only variable that always showed an acceptable reliability (CV ≤ 3.4%). L0 and F0 presented trivial to moderate correlations with the bench press 1RM and maximal isometric medicine ball push performance. Therefore, the MBT test can be implemented to reveal the maximal velocity capacity of upper-body muscles, but not maximal force or power capacities due to their low reliability and external validity.

Cuk, I, Prebeg, G, Sreckovic, S, Mirkov, DM, and Jaric, S. Generalization of muscle strength capacities as assessed from different variables, tests, and muscle groups. J Strength Cond Res 31(2): 305-312, 2017-The muscle strength capacities to exert force under various movement conditions have been indiscriminately assessed from various strength tests and variables applied on different muscles. We tested the hypotheses that the distinctive strength capacities would be revealed (H1) through different strength tests, and (H2) through different strength variables. Alternatively, (H3) all strength variables independent of the selected test could depict the same strength capacity of the tested muscle. Sixty subjects performed both the standard strength test and the test of alternating contractions of 6 pairs of antagonistic muscles acting in different leg and arm joints. The dependent variables obtained from each test and muscle were the maximum isometric force and the rate of force development. A confirmatory principle component analysis set to 2 factors explained 31.9% of the total variance. The factor loadings discerned between the tested arm and leg muscles, but not between the strength tests and variables. An exploratory analysis applied on the same data revealed 6 factors that explained 60.1% of the total variance. Again, the individual factors were mainly loaded by different tests and variables obtained from the same pair of antagonistic muscles. Therefore, a comprehensive assessment of the muscle strength capacity of the tested individual should be based on a single strength test and variable obtained from a number of different muscles, than on a single muscle tested through different tests and variables. The selected muscles should act in different limbs and joints, while the maximum isometric force should be the variable of choice.

The aim of this paper is to determine the mathematical model of relation of accuracy and precision when shooting from a pistol Zastava CZ 99 in relation to gender and short target distance. The research included 49 participants (Men = 27, Women = 22). The testing was carried out using precision shooting from CZ 99 pistol on a Standard ISSF 25 m precision pistol target at a 6, 10 and 15 m distance (5 rounds per distance). The level of performance was evaluated in relation to accuracy and precision in the function of target distance. For the sample of men, the shooting accuracy was 76.98, 62.70 and 50.61%, while for the sample of women it was 60.32, 51.03 and 37.29% for the shooting distance of 6, 10 and 15 m respectively. The precision level was 8.52, 7.01 and 5.59 points (i.e. circles) for men and 6.63, 5.61 and 4.24 points for women respectively. The defined dependency models accuracy-distance and precision-distance have shown that for men the efficiency of shooting in relation to accuracy is decreasing 2.91%, i.e. 0.32 circles, while for women the accuracy decreases 2.57%, i.e. 0.27 circles, for every meter of increase in distance.

Gun training with official weapons is one of the most important training activities in the police. The aim of this paper is to determine the relations and define the prediction model between the accuracy and precision of pistol shooting, as a specific motoric task, and the maximum muscular strength of the hand grip, as a basic indicator of general physical hand preparation. The sample covered a total of 46 subjects: students of the Faculty of Sport and Physical Education who selected the subject Shooting within the study program (N = 19, 11 male students and 8 female students), active Ministry of the Interior officers (N = 6), competitors in practical shooting, IPSC (N = 4), recreational shooters (N = 10, 8 men and 2 women), and beginners (N = 7) who have only passed one hour of basic training in firearms. For the measurement of the maximal muscle force of the hand finger flexor, a standardized test - 'grip of the hand' was used while the shooting was carried out from the CZ 99 handgun, using the precision shot method from a distance of 6 meters. Criterion variables were: accuracy and precision of shooting, while the predictive variables were the maximum forces of the left and right hand, as well as a summary indicator of the achieved maximum force level of both hands. Based on the obtained results, it can be concluded that the accuracy of shooting statistically correlates with the following variables: inversely proportional to the accuracy (r = -0.889, p = 0.000) and proportional to all variables of the maximum force of hand grip, as measures of the strength of the upper extremities ( Fmax_R, Fmax_L and Fmax_SUM at r = 0.437, p = 0.002, r = 0.439, p = 0.002 ir = 0.443, p = 0.002, respectively). In relation to the accuracy of the shooting, a statistically significant but inversely proportional correlation with all variables of the maximum force of the hand grip were determined (Fmax_R, Fmax_L and Fmax_SUM at r = -0.356, p = 0.015, r = -0.375, p = 0.010 ir = -0.369, p = 0.012, respectively). In general, based on the obtained results of this study, it can be concluded that the maximum force of the hand grip, as an indicator of arm strength, is statistically significant, and at the level of influence of 19.3% positively influences the accuracy, i.e. with 13.4% positively affects the accuracy of the shooting from the CZ 99 official handgun in a precision shooting situation from a distance of 6 meters.

Muscle fatigue is known to be associated with a deteriorated muscle coordination and impaired movement performance in variety of voluntary movements. The aim of this study was to investigate the generally underexplored effect of muscle fatigue on both the coordination between grip force (GF; the force component perpendicular to the hand–object contact area that provides friction) and load force (LF; the parallel force component that can move the object or support the body) as well as movement performance in manipulation tasks. Fifteen participants performed a variety of static and dynamic manipulations both with and without a preceding procedure designed to fatigue the arm and hand muscles. The tasks involved exertion of ramp-and-hold and oscillation patterns of LF against an externally fixed instrumented device, and a simple lift of a freely moving device. The results revealed a fatigue-associated decrease in GF scaling (i.e., the magnitude of GF relative to LF) and GF–LF coupling (correlation between GF and LF), while the task performance regarding the accuracy of exertion of the prescribed LF profiles remained unaffected. We conclude that muscle fatigue both partly decouples GF from LF and reduces the overall GF magnitude, which could potentially explain why hand-held objects are more likely to drop when manipulated with fatigued muscles. However, the unaffected task performance could be explained either by the relatively low level of muscle forces required by the tested tasks, the moderate level of the fatigue imposed, or both.

We tested the hypotheses that the individual strength properties depend on the applied test and the variable extracted, rather than on the muscle group tested. Flexor and extensor muscles acting in the knee and elbow joint were tested in 58 participants. The standard strength test (SST; based on sustained maximum contraction) and alternating consecutive maximum contractions (ACMCs; alternating contractions of antagonistic muscles) performed under static conditions were separately applied to provide the maximum force (F) and the rate of force development (RFD) of each tested muscle. The principal component analysis applied on all 16 variables revealed three factors that explained 85.5% of the total variance. Contrary to our hypotheses, the individual factors were loaded with the variables recorded from individual muscles, rather than with either the particular variables or tests. The present findings suggest that recording both F and RFD in routine strength testing procedures could be redundant since they may assess the same strength property of the tested muscle. In addition, ACMC may be a feasible alternative to SST since it could assess the same strength properties from two antagonist muscles through a single trial, while being based on relatively low and transient forces.

We compared two standard methods routinely used to assess the grip force (GF; perpendicular force that hand exerts upon the hand-held object) in the studies of coordination of GF and load force (LF; tangential force) in manipulation tasks. A variety of static tasks were tested, and GF-LF coupling (i.e., the maximum cross-correlation between the forces) was assessed. GF was calculated either as the minimum value of the two opposing GF components acting upon the hand-held object (GFmin) or as their average value (GFavg). Although both methods revealed high GF-LF correlation coefficients, most of the data revealed the higher values for GFavg than for GFmin. Therefore, we conclude that the CNS is more likely to take into account GFavg than GFmin when controlling static manipulative actions as well as that GFavg should be the variable of choice in kinetic analyses of static manipulation tasks.

The aim of this study was to defi ne the actual model of body composition status of working age women in the territory of Belgrade. The sample comprised 109 women respondents, of an average age of 35.2±9.5 and the length of service = 9.6±9.3 years. All measurements were performed in the period from 2011–2012 in the Teaching -research laboratory of the Faculty of Sport and Physical Education of the University of Belgrade, by applying stadardised procedure of electrical multichannel bioimpedance method. The researched encompassed twenty-two (22) variables – fourteen basic (14) and eight (8) derived (index) variables. Basic variables were: BH – body height, BM – body mass, ICF – intracellular fl uid, ECW – extracellular fl uid, TBW – total body fl uids, Proteins, Minerals, BMC (Osseous) – bone mineral contents, BFM – total body fat mass, SMM – skeletal muscle mass, VFA – visceral fat area, BCM – body cell mass, BMR – basal metabolic rate, FIS – fi tness score as assessment of body composition. The derived (index) variables were: BMI – body mass index, PBF% - percent of body fat, PBW - percent of body water, PFI - protein fat index, PSMM – percent of skeletal muscle mass, SMMD – skeletal muscle mass density, OBMi – Osseous-body mass index, PBMi – protein body mass index. The results showed that the average body mass of the respondents was 67.66±13.39 kg, body height 167.04±6.62 cm, body mass index 24.27±4.66 kg/m2, muscle mass 26.55±4.46 kg, muscle mass percentage 29.09±8.47, body fat mass 20.52±9.74 kg, body fat percentage 29.09±8.47, visceral fat area was 77.92±40.23 cm2 and fi tness score 73.23±6.75 of index points. The obtained results led to the conclusion that the current morphological status of the studied women partially corresponds to a type of normal weight. BMI and the representation of body fat had nearly limiting values towards obesity. A very high percentage of women was recorded in the category of pre-obese and obese according to BMI (40%) and PSMM (36%). Based on the results of this study, it can be claimed that the four-dimensional model (4D model) of body composition of working-age women from the measured sample has the following characteristics: in women of average body mass of 67.66 kg – water content is 34.58 L or 51.11%, protein mass is 9.25 kg or 13.68%, mineral mass is 3.30 kg or 4.88% and fat mass is 20.25 kg or 30.32%.