Dr.Med., Professor A.B. Gudkov^{1, 2}
Postgraduate student A.A. Dolgoborodova²
PhD A.V. Demin²
PhD, Associate Professor A.V. Bykov^2
1Northern State Medical University, Arkhangelsk
²Northern (Arctic) Federal University named after M.V. Lomonosov, Arkhangelsk

Introduction. To date, the study of postural control skills is gaining more and more practical importance in sports. The ability to maintain the necessary posture while the athlete is moving is the most significant aspect of athletic technique [8]. Man’s postural control skills are seen as the peculiarities of the center-of-gravity motion control within the support base when performing various dynamic actions (standing up, walking, running, etc.) [5]. However, the analysis of the scientific literature revealed the lack of studies on the above aspects in relation to the patterns characteristic to athletes from team sports, in particular floorball.

Objective of the study was to rate the static/dynamic (postural control) balancing skills in skilled women’s floorball players in a post-competitive period.

Methods and structure of the study. Randomly sampled for the study were the Arkhangelsk Oblast picked team members (n=17) aged 25.1±5.6 years on average, free of serious injuries in the study period. All examined female athletes had the Master of Sports title and played either offense or defense. The study was conducted in the first week after the 2015 Women's World Floorball Championship (December 4th-12th, Finland, Tampere). The Experimental Group (EG) was made of the Masters of Sports whose floorball experience did not exceed 10 years (from 5 to 9 years). The Reference Group (RG) - of the Masters of Sports involved in floorball for more than 10 years (from 10 to 19 years).

Postural control skills of the sample were tested by "Balance Master" postural control (stabilograph) test system using Tests 2-7.

"The Modified Clinical Test of Sensory Interaction on Balance – MC" was used to make a quantitative assessment of the sway speed when the subject was calmly standing on the platform, first with eyes open, then with eyes closed.

The "Unilateral Stance – US" test revealed the deflection rate when the patient was standing on one leg on the platform with eyes open and closed. The center of gravity movement speed showed how well the subject fulfilled the test conditions. Its low rates reflected some minor displacement, while its high rates testified to ​​greater movements and indicated a possible pathology.

The "Sit to Stand - ST" test was used to assess the peculiarities of standing up from a sitting position. The following parameters were measured: Weight Transfer Index, Rising Index (the force used to stand up), and Sway Velocity. Standing up from a sitting position is a standard functional activity [3].

The "Walk Across – WA" test was used to make a quantitative assessment and identify the common features of simple walking when the subject was moving from one end of the platform to the other. But since the survey involved the highly-skilled athletes - Masters of Sports in floorball, the test was modified for this group. The female athletes were to walk along the platform 3 times, dribbling the ball with a stick. The following indicators were evaluated: Mean Step Width; Mean Step Length; Mean Speed.

The "Tandem Walk – TW" test was used to quantify a number of indicators of the subject’s complex coordination movements when walking in a straight line from one end of the platform to the other, sequentially placing the toe to the heel as close as possible. This test was also performed 3 times. The following indicators were estimated: Mean Step Width; Mean Speed and Mean End Sway - the average deflection speed in the anteroposterior (A/P) direction during the first 5 sec once the forward movement had ceased.

The "Step/Quick Turn – SQT" test was used to make a quantitative assessment of a number of walking characteristics when the subject was making two steps forward, a quick half turn (180°) and a step back to the starting position, making it possible to evaluate Mean Turn Time and Mean Turn Sway (3 attempts). Here, two functional tests were distinguished depending on the first step and turn: Left Side – when starting with the left foot with a quick half turn (180°) over the left shoulder; Right Side - when starting with the right foot with a quick half turn (180°) over the right shoulder. Both tests were performed 3 times.

The "Forward Lunge – FL" test was used to quantify a number of movement characteristics when the subject was performing a lunge or a step forward, followed by pushing back with the same foot to return to the initial standing position. The following parameters were measured in this test: distance, travel time, push-off index (push-off force) and impact force. We determined Mean Distance - the average forward step length; Mean Contact Time - the average amount of time that the lunging leg was in contact with the surface before taking a step forward; Mean Impact Index - the average value of the maximum force transmitted to the lunging leg before it touched the surface. The indices obtained for the left leg in all three tests were summed up and divided by three to derive the mean value for the left side (Left Side); the indices obtained for the right leg in all three tests were summed up and divided by three to derive the mean value for the right side (Right Side). In addition, Mean Force Impulse - the average amount of work performed by the lunging leg in the landing and repulsion phases, expressed as a percentage of body weight (force) and in seconds (time).

Results and discussion. The comparative analysis did not reveal any statistically significant differences in almost all test rates. The data obtained suggested positive dynamics of movement in various directions relative to the support, which was a significant characteristic for the team players, especially highly-skilled female athletes, when performing any technical element or deceptive movement. For a field player, the ability to move, move in different directions in a short period of time, as well as the ability to coordinate his/her actions should be an integral part [6]. The research suggests that adaptation to physical loads of complex coordination nature, in particular team sports, leads to an increase in statokinetic stability [7]. In this view, it can be assumed that multi-year athletic training enables highly-skilled athletes from team sports to develop high dynamic equilibrium. The absence of statistically significant differences in almost all test rates confirms this assumption.

"The Modified Clinical Test of Sensory Interaction on Balance" was an exception when the hard surface was changed to the soft one at the first attempt. The analysis of the test rates revealed some statistically significant (p=0.062) differences between the two groups. Based on the data obtained, it can be assumed that in the competitive period the female floorball players with less than 10 years of experience face a risk of losing balance when familiar conditions suddenly change with a quick change in the game situation.

The mean value of all 3 attempts made in the "Unilateral Stance" test, standing on the left leg with eyes closed, were also characterized by statistically significant differences (p=0.078). During this test, the center of gravity movement speed in the female floorball players with more than 10 years of experience were higher than in those from Experimental Group. Earlier studies showed that a combination of long-term sports selection and long-term adaptation to the specifics of training leads to the development of functional asymmetry in all highly-skilled athletes [6], which can cause a decrease in the test rates for the non-dominant leg, as confirmed by the current study. Dynamic equilibrium is known to result from postural reflexes, realized based on the interaction of vestibular and spectral analyzers, and muscle-joint proprioreception [1, 2, 9]. In this view, there is a risk of reduction of the volume of vestibular information in balance control during the competitive period by limiting the degree of participation of visual information in postural control and functional asymmetry in female floorball players.

The mean value of standing up in the "Sit to Stand" test was also characterized by the statistically significant differences in all 3 attempts (p=0.098). The stand-up force values were lower in the female floorball players form Experimental Group. The results obtained suggested that the less experienced female athletes had more serious functional shifts in the competitive period, which resulted in the lower level of functional fitness.

The first attempt of the modified "Walk Across" test revealed the statistically significant differences in the average moving speed (p=0.007). The speed of movement of the female floorball players from Experimental Group was much lower than that of the female athletes from RG, which was probably due to the greater stability of mental processes which improved with increasing training and competitive experience. The low speed of movement demonstrated by the less experienced female floorball players at the first attempt may be due to the stiffness, development of fear, fear of making a mistake or completing the task unsuccessfully [4]. In this view, it can be assumed that with changing conditions and increasing load in the balance control, the less experienced female floorball players had a decrease in the ability to adapt and recover quickly.

Conclusion. In order to increase the efficiency and effectiveness of competitive performance and improve the players’ adaptation, it is advisable to include a novelty aspect (new exercises) in the training process, which, in turn, will facilitate progress in the sport-specific physical, biomechanical and mental qualities and skills. Due to functional asymmetry developed in the course of multi-year athletic training and a greater emphasis on the dominant side of the body, it is recommended to add exercises for the non-dominant side.

It should also be emphasized that the introduction of computer stabilometry (posturography) in practice of sports medicine will be useful for annual monitoring of postural control skills in athletes, which will make it possible to detect changes in their postural control and reduce the risk of sports injuries in a timely manner.

References

1. Babiyak V.I. Vestibulyarnaya funktsionalnaya sistema [Vestibular functional system]. St. Petersburg: Gippokrat publ., 2007. 432 p.
2. Gage P.-M. Posturologiya. Regulyatsiya i narusheniya ravnovesiya tela cheloveka [Posturology. Regulation and imbalance in human body]. St. Petersburg: SPbMAPO publ., 2008. 316 p.
3. Gudkov A.B., Demin A.V. Osobennosti posturalnogo balansa u muzhchin pozhilogo i starcheskogo vozrasta s sindromom strakha padeniya [Features of postural balance in elderly and old men with syndrome of fear of falling]. Uspekhi gerontologii. 2012. vol. 25. no. 1. pp.  166-170.
4. Gudkov A.B., Demin A.V., Dolgoborodova A.A., Bykov A.V. Kharakteristika posturalnogo kontrolya u florbolistok natsionalnoy sbornoy Rossii v sorevnovatelny period [Russian women's national floorball team in regular season: postural control rating study]. Teoriya i praktika fiz. kultury. 2017. no. 2. pp. 23-26.
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6. Dolgoborodova A.A. Osobennosti dinamicheskogo balansa u vysokokvalifitsirovannykh florbolistok [Features of dynamic balance in highly skilled female floorball players]. Lechebnaya fizkultura i sportivnaya meditsina. 2016. no. 5 (137). pp. 15-19.
7. Zinurova N.G., Denisov K.G., Kuzikov M.M. Pokazateli statokineticheskoy ustoychivosti sportsmenov pri adaptatsii k slozhno-koordinatsionnym nagruzkam [Statokinetic resistance of athletes when adapting to complex coordination loads]. Vestnik Yuzhno-Uralskogo gosudarstvennogo universiteta. Obrazovanie, zdravookhranenie, fizicheskaya kultura. 2011. no. 26. pp. 127-130.
8. Shestakov M.P. Ispolzovanie stabilometrii v sporte [Stabilometrics in sports]. Moscow: TVT Divizion publ.. 2007. 112 p.
9. Brooks V. Learning «what» and «how» in human motor task. LearnMem., 1995. Vol. 2, no. 5. pp. 225-24.

Corresponding author: stas5i@yandex.ru

Abstract

Objective of the study was to rate the static/dynamic (postural control) balancing skills in skilled women’s floorball players in a post-competitive period. Randomly sampled for the study were the Arkhangelsk Oblast picked team members (n=17) aged 25.1±5.6 years on average, free of serious injuries in the study period. The postural control skills of the sample were tested by Balance Master postural control (stabilograph) test system using the following tests: Modified Clinical Test of Sensory Interaction on Balance (MC); Unilateral Stance (US); Sit to stand (ST); Walk Across; Tandem Walk (TW); Step/Quick Turn (SQT); and Forward Lunge (FL) tests. The test data and analyses were used to put together recommendations on how the competitive performance and adaptation may be improved by new exercises to facilitate progress in the sport-specific physical, biomechanical and mental qualities and skills.