Postgraduate A.V. Lovchev¹
Dr.Hab., Professor Yu.P. Kobyakov^1
1Vladimir State University named after A.G. and N.G. Stoletovs, Vladimir

Keywords: clean and jerk, superheavyweight class, movement biomechanics, body length, correlation analysis.

Background. Study of the available study reports on the subject and our own multiannual coaching experience has showed that the factors of influence on the competitive success in the weightlifting sport on the whole and the superheavyweight class in particular – tend to grow in numbers. Some researchers [7, 8] mention a variety of internal and external factors of influence, including the distracting ones, on the competitive progress, with the latter being in focus of special studies for quite a long time [2, 4, 6, 9]. Thus N.P. Volkov and K.Y. Danilov offered the clean and jerk elementary movement biomechanics classification [1] including 8 and 13 motor units for the clean and jerk phases, respectively – albeit their movement biomechanics analyzing method has not been widely applied since then.
Theoretically there are good reasons to expect an equal positive correlation of the two key anthropometric characteristics (body weight and length) with the key parameters of the elementary movement biomechanics. The research interest to these issues has been growing with the growing versatility of the technique demonstrated by the world leading superheavyweight athletes.
Objective of the study was to check the assumption that the weight lifting movement biomechanics may be correlated with the body length in the superheavyweight class.
Methods and structure of the study. We used video captures of the clean and jerk executed by 13 world record holders in the superheavyweight class for the period of 1960-2015, with the movement sequence grouped into 8 elementary phases (motor units, see Figure 1 hereunder), and with the total path of the weight sectioned as described in our prior study [3]. Then we quantified each of the 8 elements with a 1cm accuracy followed by calculations of the pair correlations for each of the parameters.
Results and discussion. The clean and jerk movement biomechanics analysis showed a certain variability of the technique in the elite sport. The statistically processed study data demonstrated the null hypothesis being wrong. Correlations between the key parameters were found to gradually grow from the starting to finishing points of the movement sequence. Only the squat phase depth was found weekly correlated with the body mass (r=+0.30), whilst every of the other seven elements were tested with the high (r=+0.79-0.90) to very high (r=+0.96) correlations between the weight movement points and body length: see Figure 1 hereunder.

Figure 1. Correlation between the weight movement points and body length for the world record holders in the superheavyweight class

The study data and analysis confirmed the prior assumption that the weight lifting movement biomechanics may be correlated with the body length in the superheavyweight class. The clean point height and squat depth was found in a direct correlation with the weight, with the parameters for every phase found to fall with the weight growth. Our analysis showed the clean and particularly squat being the key technical elements of the clean and jerk sequence. The movement biomechanics analysis also showed that the lower correlations of the elementary parameters in the first phases of the movement may be due to the lower limb segments (shin, thigh) lengths and qualities (knee and hip joint mobility rates) rather than the total body length as such. The differences in the clean and jerk techniques of the superheavyweight class leaders, hence, may be explained by their differences in the anthropometric specifics particularly telling on the first phases of the movement sequence. It may be assumed that the clean and squat execution biomechanics found by the study may be weight-class unspecific, although this assumption needs to be checked by further studies.

Conclusion. We would summarize, based on our own experiences and practical studies plus experiences of a few leading national coaches (including S.V. Ivanov and V.V. Lovchev), that the individual weightlifting techniques of the global sport elite are influenced, among other factors, by their national weightlifting schools – as verified, for example, by the obvious differences in the weight handling techniques of the-then world leaders – the Soviet Union and Bulgaria national weightlifting teams.

References

1. Volkov N.P., Danilov K.Yu. Strukturnaya klassifikatsiya i zapis edinits dvigatelnoy deyatelnosti v tyazheloy atletike kategoriy [Structural classification and recording of units of motor activity in weightlifting categories]. Tyazhelaya atletika. Ezhegodnik [Weightlifting. Yearbook]. Moscow: Fizkultura i sport publ., 1985. pp. 46-53.
2. Ivanov A.T., Roman R.A. Tekhnika vypolneniya tolchka shtangi ot grudi rekordsmenami mira V. Kurentsovyim i D. Rigertom [Clean and jerk technique by world record-holders V. Kurentsov and D. Rigert]. Tyazhelaya atletika. Ezhegodnik [Weightlifting. Yearbook]. Moscow: Fizkultura i sport publ., 1976. pp. 42-46.
3. Kobyakov Yu.P., Lovchev A.V. Novy podkhod k izmereniyu trenirovochnoy nagruzki v tyazheloy atletike [New training load rating method in weightlifting]. Teoriya i praktika fiz. kultury. 2018. no. 1. pp. 78-80..
4. Livanov O.I., Falameev A.I. O nekotorykh biomekhanicheskikh kharakteristikakh dvizheniya shtangi v ryvke i pri pod'eme na grud [Some biomechanical characteristics of barbell snatch movement and hand squat]. Tyazhelaya atletika. Ezhegodnik [Weightlifting. Yearbook]. Moscow: Fizkultura i sport publ., 1979, pp. 22-25.
5. Roman R.A., Shakirzyanov M.S. Zhim, ryvok, tolchok. Tekhnika luchshikh atletov mira [Clean and jerk. Technique of the best athletes of the world]. Moscow: Fizicheskaya kultura i sport publ., 1970, 144 p.
6. Roman R.A., Shakirzyanov M.S. Tekhnika tolchka shtangi mirovym rekordsmenom V. Marchukom [Cean and jerk techniques by world record holder V. Marchuk]. Tyazhelaya atletika. Ezhegodnik [Weightlifting. Yearbook]. Moscow: Fizicheskaya kultura i sport publ., 1982. pp. 30-33.
7. Skotnikov V.F. Partsialnye ob'emy nagruzki (s otyagoscheniem і70%) v osnovnykh gruppakh uprazhneniy u silneyshikh tyazheloatletov mira 80-kh godov v zavisimosti ot massy tela i tipa podgotovki [Partial load volumes (with ≥70% weight) in main exercise groups for the strongest weightlifters of the world in the 80s, depending on body weight and training type]. PhD diss.. Moscow, 1995. 148 p.
8. Smirnov V.E. Raspredelenie nagruzki po zonam intensivnosti v osnovnykh gruppakh uprazhneniy u silneyshikh tyazheloatletov mira 80-kh godov v zavisimosti ot massy tela i etapa podgotovki. Dis. kand. ped. nauk [Load distribution by intensity zones in main groups of exercises for the strongest weightlifters of the world in the 80s according to body weight and training stage. PhD diss.]. Moscow, 1996, 180 p.
9. Frolov V.I., Levshunov N.P. Fazovaya struktura tolchka shtangi ot grudi [Phase structure of clean and jerk]. Tyazhelaya atletika. Ezhegodnik [Weightlifting. Yearbook], Moscow: Fizkultura i sport publ., 1979, pp. 25-28.

Corresponding author: reger89@mail.ru

Abstract
The study analyzes the superheavyweight clean and jerk movement biomechanics versus the body length of the world record holders for the period of 1960-2015, with the movement sequence grouped into 8 elementary moves (motor units). The analysis was intended to check the assumption that the weight lifting movement biomechanics may be correlated with the body length. We applied a match correlation method to find a positive correlation between the movement sequence elements and body lengths – albeit the correlations were found widely varying and falling in conflict with the null hypothesis. It was further found that the clean height and squat depth are determined by the movement sequence elements rather than the body length alone. The data analysis completed on a systemic and logical basis found the correlations of the motor elements being determined by the length of the lower limb elements (shin and thigh) and their joint flexibility rates. The study data arrays and analyses give the reasons to conclude that these elements altogether largely determine the individual clean technique critical for success of the clean and jerk sequence.