PILOT STUDY: KINEMATIC ANALYSIS OF THE TECHNIQUE OF THE EXERCISE "BACK UPRISE TO MALTESE CROSS" ON RINGS IN THE MEN'S GYMNASTICS

Abstract

This is a pilot study, because our chosen element of gymnastic rings is technically complex and requires a high level of professional gymnastics training. In the national team of the Republic of Bulgaria there are only three athletes who perform this exercise. The aim of our research is to analyze the fundamentals of the kinematic and reveal phase structure of the technique during the execution of "Back uprise to Maltese cross" element of Rings in men's gymnastics. To analyze the spatial parameters of the exercise: phases; technical performance parameters; angular positions in joint centers; center of gravity displacement trajectory; angular velocity; conditions for balance in the Cross position. To determine the displacement of the athlete's general Center of gravity (COG) when performing the exercise and analysis of a rational performance technique. We used the cinematographic method , which includes a segmental analysis of the kinematic chain of successively filmed frames of the exercise performance. We determined the trajectory of the COG movement and the phases of the "MC" element during accelerating angular motion. The subject of research is the transposition of the center of gravity relative to the athlete's kinematic chain and its location during the static Maltese cross exercise, as a condition for balance. We analyzed the performance technique of a competitor who has 17 years of competitive sports practice. long-time champion of the Republic of Bulgaria in the sports all-around and rings apparatus, participant in the World Cup series of the International Gymnastics Federation (FIG). Anthropometric characteristics of the subject: height 165 cm, weight 56 kg, age 23, BMI of 20.6 kg/m2. We used a Go Pro HERO 12 Black HDR 5.3K and 4K camera to capture the photo frames. Graphic processing was done with PAINT 3D program, Windows 10. Kinematic (qualitative) analysis includes analysis of the following parameters: movement trajectory; phases of movement; angular positions in joint centers; angular velocity; conditions for static or dynamic stability without including an analysis of the forces that impart motion to the body, which is actually called kinetic analysis. We have defined four main phases of the exercise: 1) first phase of the backflip swing; 2) phase passing through vertical line and swing to backward; 3) phase of rise and preparation for taking the Maltese Cross; 4) final position of holding the Maltese Cross pose. We determined the location of the Center of Gravity in each of the phases and by projection determined its displacement trajectory. We found that in the static position in the Maltese Cross pose, the angular position of the kinematic pair of arm and forearm in relation to the mechanical axis of the torso must make an angle of 40o. Under this condition, the COG will pass through the line connecting the two supports (the grip of the palms) and will balance the resulting lever system of the first order (expressed by the formula P1 x r1= P2 x r2), where P1 is the sum of the weight of the head, torso and upper limbs, and P2 is the sum of the weight of the lower limbs. We also determined the amplitude of movement of the COG - the angular displacement is in the range of 270o; duration of the exercise – the exercise performed for the research process is for 1.5 sec and the average angular speed of execution of 180о/sec.