Analysis of shooting techniques of the archers with kinetic and kinematic methods

In this study it has been aimed to analyze the shooting techniques of the archers with kinetic and kinematic methods. Twenty-seven archers including nine elite (age: 25,5 ± 8,3 years; training age: 8,7 ± 4,9), nine mid-level (age: 23,8 ± 7,6 years; training age: 6,6 ± 3,3) and nine novice archers (age: 22,6 ± 6,0 years; training age: 1,4 ± 0,5) have been volunteered to take part in the research. Furthermore, in this study muscular activation measurements of the nine muscles belonging to the traction arm during the arrow shot have been made (M. Flexor digitorum Superfacialis (SDFT), M. extensor digitorum communis (MEDC), M. Deltoideus anterior (MDA), M. Deltoideus Middle (MDM), M. Deltoideus posterior (MDP), M. Pectoralis Major (MPM), M. Upper trapezius (MUT), M. Middle trapezius (MMT), M. Lower trapezius (MLT)) using a 16-channel system named "Delsys Trigno Electromyography (EMG)". Anterioposterior (Ax) and Mediolateral (Ay) postural sway values during the successful shots towards the goal from a distance of 18m have been determined to be in the size of 600x400x100 mm by means of a German branded force platform measurement system model named "Kistler 9281EA". The 3-D kinematic analysis of the arrow shot has been conducted by using the videography methods which include two high-speed cameras possessing the brand "Motion BLITZ EoSense Cube 7", the moving speed 500 fps, the resolution 1696x886 pixels, the shutter settings 998 and the gain 1. The cameras have been positioned 1.5 m above the ground and at an angle of 70 degrees to each other. In order to calibrate the images where the subjects do the shooting, a calibration cage with the size of 165x106x75 cm and twelve control points has been used. Marker have been fixed in seventeen regions of the bodies of the subjects. Delsys Trigger Module, which can make BNC cable connection, has been used for the synchronization of MotionBLITZ EoSense Cube 7 brand high-speed cameras, Kistler 9281EA Force Platfrom and DelsysTrigno Wriless EMG system. The data obtained have been evaluated using the SPSS 20.0 statistical software package. ANOVA test has been applied to determine the muscular activation differences that emerge throughout the implementation of the arrow shot techniques of the elite, mid-level and novice archers and Tukey-W test as the PostHoc test has been chosen to present from which group the differences stem. According to the muscular activation evaluations made, a statistically significant difference (p<0.05) has been observed among the archer groups in MFDS, MEDC, MDM, MDP, MMT and MLT. Although there has been no statistical significance (p>0.05) in the time-dependent exchange values of the angle of the joints, a difference has been detected in the graphical sense. There have been 11observed statistically significant differences (p<0,05) between elite archers and novice archers group in terms of the Ax and Ay postural sway range values of the archers. During the arrow shot, the Ax and Ay postural sway range values and reaction length of the elite archers are lower than the mid-level and novice archers. In the archery branch, differences have been determined in the muscular activation pattern. The neurophysiological mechanism underlying this difference varies depending on the motor skill learning phases in which the archers are. The elite archers who are at the ultimate phase of the acquisition of motor skills show specific muscle activation ("Reciprocal Inhibition") in the flexor and extensor muscle groups. The mid-level archers who are in the phase of association of motor skills learning show "Co-Activation" strategy by activating the flexor and extensor muscles simultaneously and exhibit their way to becoming elite. On the other hand, the novice archers who are at the first phase of the acquisition of motor skills grab tightly the girder with their fingers by activating the traction forearm flexors. They carry the girder with a lot of contraction at the phases of full extension and aiming. In other words, they use distal muscles instead of stretching the bow by means of larger muscle groups that surround the glenohumeral and scapular joint. This shows that postural sway values increase due to not being able to use distal and axial muscles in a coordinated manner. According to the results of this study, it has been determined that EMG, Force and Visual Biofeedback are necessary to provide the archers with the desired muscular activation pattern.Key Words: Archery, Electromyography (EMG), Force, Kinematic, Kinetic, Muscular Analysis.