Factors affecting lateral preferances shown in the ones involved in fitness aerobics

Фотографии: 

ˑ: 

L.A. Kochurova, postgraduate student Ulyanovsk state pedagogical university named after I.N. Ul'yanov, Ulyanovsk
 
Key words: fitness aerobics, motor preferences, key factors, pedagogical experiment, technique of classes, physical fitness, personality-focused approach, all-round development.
 
Relevance of the research. The study of various symmetrically organized organs testifies to the specifics in respect to functioning of the right and left parts of the human body. Proceeding from specialized researches, cerebral impulses first reach the muscles of the left upper and lower extremities, thus people with sinistral lateral preferences are distinguished by quicker response to incoming external signals [3, 5]. It is very important in physical and sports activity to take into consideration asymmetry due to the high level of technical and tactical skills of the leading athletes of the world, where success is related with the athletes’ ability to reveal their individual characteristics and abilities.

The aesthetic types of physical activity, fitness aerobics refers to, are not related to coping with ultimate neuromuscular and mental loadings. Staginess of performance in this kind of physical culture is obtained by the high accuracy of reproduction of the forms of motor acts, plasticity and expressiveness, artistry of movements, via the accurate coordinated performance of motor acts, steady muscle tension, timely reallocation of muscular efforts, freedom and easiness in making steps with comprehensive coordination, jumps, turns and dance steps in their various combinations. Hence all the factors influencing the formation of skills of the involved in fitness aerobics are to be considered, including the peculiarities of manifestation of motor asymmetry [1, 2].

The purpose of the study was the theoretical and methodological substantiation of the importance of considering specific features of lateral motor preferences.

Proceeding from the studies of the peculiarities of manifestation of motor asymmetry right-hand actions are not absolutely dominant in all motor acts even among people with dextral motor preferences.
According to N.N. Bragin, T.A. Dobrokhotova, 1981, athletes with right-sided motor asymmetry are distinguished by specific motor coordination qualities: strength, agility and accuracy of movement and dexterity are better developed in the right hand muscles, while the left limb muscle groups are more resistant to static efforts.

The studies of T.P Yushkevich [6] distinguished the strength indicators of the same muscle groups for the right and left lower extremities. While analyzing the peculiarities of manifestation of power asymmetry, the author concludes that the growth of athletes’ sports skills in running sports is essentially related to development of the symmetrical lower extremity muscle groups. This stipulates for introducing specific exercises in the training sessions to increase muscle strength of a weaker limb, keeping natural lateral preferences. Here the detected peculiarities of the dynamics of manifestations of motor asymmetry in case of developing sports kills of athletes of different qualifications are of great interest. As proved by the educational experiments, the initially slight difference among novice athletes in terms of strength of the take-off foot and switch leg get more significant with developing fitness, reaching its maximum at the second grade level followed by the variance decreasing with sports achievements.

Meanwhile, the obtained data clearly showing the intention to achieving full symmetry of the lower extremity muscles is impractical, namely the optimal asymmetry is to be considered as a material basis of the regulatory phenomenon. Choosing the ways how to reduce the symptoms of motor asymmetry one is to consider that asymmetric exercises contribute to the stabilization of the spatiotemporal and spatio-power characteristics of motor actions, which significantly expands the limits of sports achievements. Therefore, it is of special importance to allocate the factors influencing the reduction of lateral preferences. Proceeding from the literature analysis on the topic of the study and personal investigations, these factors are as follows:

- physical fitness level;
- genotypological characteristics of the central nervous system;
- technology of training sessions based on the personality-centered approach and considering the rules of physical development and functional status.

The specific feature of fitness aerobics is its all-round effect on all muscle groups, physiological systems of the body, as well as controlling psychoemotional status, providing for regulating physical working capacity of the involved ones. Proceeding from our studies, the symptoms of motor asymmetry can be reduced by starting and finishing performing each motor action with a weaker limb. The peculiarity of fitness aerobics is the need for the coordinated movements with upper and lower extremities. This should be considered when performing motor acts intended to increase muscle strength indicators of the weaker limb.

When identifying a physical fitness level it is important to establish all possible manifestations of motor asymmetry:

- stronger right hand and leg;
- better indicators of right and left hand muscle strength;
- stronger left hand and right leg.

The allocation of these features of manifestation of motor asymmetry stipulates for designing the structure of physical exercises provided for strengthening the weaker limb muscles and ensuring coordinated movements of opposite and homonymous extremities. So in fitness aerobics the combinations of program performances are designed on the high coordination of upper and lower limb movements, temporal distribution of solution of a motor task to achieve the necessary level of coordination of motor acts first with upper extremities to the optimal level. Only then one can start the second training phase to achieve coordination of the lower limb movements. The role of the optimal motor coordination is determined by the generated conditioned reflex when minimal involvement of consciousness is required to control single elements of a rather complex motor action. The level of motor coordination increases with the increment of the indices of muscle strength of upper and lower extremities, which are weaker. This indicates to the more complex structure of physical fitness of the involved ones with different lateral preferences, compared with similar manifestation of motor asymmetry.

The genotypic features of the central nervous system as a factor influencing the manifestation of lateral movement preferences, need more attention, since it is hard for the subjects with significant manifestations of motor asymmetry to control the spatio-power and spatiotemporal characteristics of motor actions, that requires using special training and educational methodologies and, therefore, designing a fundamentally new training technology.

The abovementioned conditions were controlled by means of the educational experiment with 36 subjects engaged in fitness aerobics aged 17-20, divided into a control group (CG) - 17 subjects and experimental group (EG) - 19 subjects. The peculiarities of their motor lateral preferences were detected using special tests. The CG included 6 subjects with sinistral asymmetry, 11 with dextral asymmetry, and 7 and 1 for the EG respectively. Before the educational experiment the base values of physical fitness of the subjects of the CG and EG were allocated using the following tests:

- throwing a medicine ball (1 kg) for distance (m) with both arms;
- one step long jump, first with the left and then with the right foot (cm);
- one step standing high jump with the left and then the right foot take-off;
- running jump with alternating left and right foot take-off;
- front lying position with alternating support on a stronger arm (s) and on a weaker arm (s), free hand up to the body.

The data processing failed to reveal any significant differences in the physical fitness level of the subjects of the CG and the EG (p> 0.05). Moreover, the level of motor coordination was estimated for upper and lower extremities. This index was assessed by an expert group of 5 trainers of various sports clubs. The factors taken into account were as follows: range of motion in the upper and lower extremities, matching of effective head actions at the final phase of arm swings, range of motions of lower extremities when making dance steps with the range of arm swings and circles.

The analysis of the findings had not revealed any significant differences in terms of motor coordination among the subjects of the CG and the EG. In the CG training sessions were held in accordance with the standard methods, while the EG used our new technology intended to reduce motor asymmetry of the subjects with different lateral preferences.

According to the educational technology subjects were to perform motor actions moving more with their weaker hand and foot. So, forward walking lunges with the right foot are accompanied with a strong and effective swinging with the left arm making a parallel line with the right hip. Left hand movements are performed with the palm up, the wrist turned simultaneously with the right foot placed on a support to make a stronger movement with one step with the right foot. The moment of focused muscular efforts can be enhanced via a musical chord, metronome, hand clap or trainer’s voice.

When performing a dance step with consecutive arm circling motions backwards, each of its elements should match the arm swinging motion and the directed moves with the weak hand should match the most dynamic part of the dance step that is stressed by strong musical beats and other sound stimuli. The dancer moves his head accordingly to make motions more coordinated.

The aesthetic aspect of fitness aerobics is enhanced by the static and dynamic posture, making the range of movements more precise. Every exercise is performed by turn with one and another extremity, but the motion cycle starts and finishes with a weaker arm and foot. Conditioning exercises are performed in the same way (both when warming up, doing preparatory exercises and at the end of the main part when motor tasks are performed to improve motor coordination qualities).

Exercises with various objects make stronger muscles of the weaker extremity. These are exercises with gymnastic sticks, when at the end of each movement the weaker arm marks the final phase of the action by the direction of the stick position making one line with arms, and the need to keep it working makes the muscle load more strenuous. Dumbbell exercises (0.5 kg) also contribute to the increase of the muscle strength indicators for both of the hands, focusing mostly on the weaker extremity. Thus, making a heelball-toe roll step, the weak arm with a dumbbell is raised forward, the strong arm goes down and back. In order to ensure motor coordination the opposite arm is taking its final position with the supporting foot being raised into the tiptoe position and the head moving forward and upward. The clarity and aesthetics of the exercises performed is provided by the exact correspondence of power and spatial and spatial and temporal characteristics of motor actions. Rhythmic music conditioning the range of the upper and lower extremities is very useful for these purposes. Accented postures, end of each part of the composition should be stressed with more effort on a weaker hand. Thus, focusing on strengthening the weaker limb movements and timely redistribution of muscle tension is a principal precondition of reduction of explicit lateral preferences.

The educational experiment was followed by the re-testing of the physical fitness level and motor coordination. The findings showed improvement in both of the groups, but the indices in the EG were proved to be higher than in the CG. Thus, the indices in throwing a medicine ball (1 kg) with the left hand increased by 4.72% in the CG and by 12.36% (p <0.05) in the EG by the end of the experiment (at initial indices equal to 7,98 ± 0,56 m and 7,83 ± 0,62 m respectively). In the right hander the results improved by 5.19% (p> 0.05) in the CG and by 11,35% (p <0.05) in the EG (with the input data of 9,06 ± 0,64 m and 9,24 ± 0,52 m respectively). In the long jump with the left foot take-off (one-step) the increment was 3.98% and 12.64% (p <0.05) for the EG and CG respectively (at the input data 174,35 ± 10,26 cm and 176,29 ± 13,05 cm) and in the same jump with the right foot - by 2.76% and 9.77% (p <0.05)  (originally 161,24 ± 11,80 and 159,87 ± 12,05 cm accordingly). A similar trend was marked in all other fitness indices.
Regarding motor coordination, the indices increased by 6.19% in the CG and 14.21% (p <0.05) in the EG after the experiment (with the input data amounting to 2,76 ± 0,15 and 2,64 ± 0,21 points respectively).
Hence, as shown by the results of the educational experiment, when organizing the fitness aerobics training process one should take into account the specific features of lateral motor preferences of the ones involved and teach physical exercises, included in the quoted type of physical training and sports activity, as well as remember the factors affecting motor asymmetry manifestation. It stipulates for the application of the personality-centered approach to the ones involved, ensures the essence of the positive psychoemotional background, convinces of the need for all-round physical development by strengthening the weaker arm and leg muscles and preserving natural lateral preferences.
 
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Author’s contacts: еlena-funina@mail.ru