Kick as key combat technique for success in kickboxing

PhD, Professor S.I. Belykh1
O.S. Oleynik1
1Donetsk National University, Donetsk

Keywords: strike speed, strike power, kickboxing, training, progress.

Background. Strike may be described as the explosive straight or non-linear movement sequence exercised by the chain of the relevant bodily elements, and generally the core action for success in a kickboxing bout scored by standard points (when legal) as regulated by the rules of competitions. Strikes may be classified by their kinematics, with the movement sequence and speed varied depending on the goal. Issues of the strike power trainings driven by the movement biomechanics analysis deserve being studied in more detail.

Objective of the study was to use the process biomechanics analysis to identify the factors of influence on the strike power.

Methods and structure of the study. We applied for the study purposes special technical tools and test equipment; submaximal endurance exercises; weighted exercises; and interval trainings and competitions. The study was run at the kickboxing and boxing clubs in the Donetsk Oblast where 25% of the Ukraine national kickboxing team come from. We used electromyograms and 16mmvideo captures to rate the strike speed and power.

Results and discussion. Punch speed rating data show the speed being skill level specific (meaning among other things that the elite boxer’s fist reaches target much faster than the beginner’s), with a notable acceleration at the final stage of the movement sequence. Having split up the movement trajectory into 100 provisional segments, we found (in 20 cases out of 23, i.e. 87%) the punch speeds reaching their maximums in sections 70 to 80. Given in Table 1 hereunder are the electromyographic test data (2V DC, 1/100s) for the skills-specific punch sequences.

Table 1. Skills-specific punch sequence biomechanics in kickboxing

Skill level

Punch time, s

Average speed, m/s

Maximal speed, m/s

Final-stage speed, m/s

Straight punch

MS

0,156

5,06

7,10

5,16

CMS

0,219

3,25

6,71

4,48

Class I

0,219

2,88

4,68

2,90

Hook

MS

0,157

5,52

12,64

8,21

CMS

0,218

5,84

11,45

7,78

Class I

0,219

3,35

7,10

4,56

It should be mentioned that the high-speed punches expose the muscles to the higher risks of damage. Thus a regular punch is generally profiled by a week gradually growing wavelike electrical activity, whilst a top-speed punch is profiled by a hackly curve, with the final-stage lows indicative of the core muscles being immediately relaxed. In a sequence of 6 punches, the first two were profiled as described above, whilst electromyograms of the remaining four punches showed the stress and fatigue being accumulated in the muscles.

Strike power in the study was found using the formula F = (V0т k1k2)/ t, where V0 means the strike speed at the contact point, m/s; т is the strike weight, kg; kt means the target stiffness ratio;k2 means the strike trajectory ratio; and t  means the contact time, s.

The factors of influence on the strike power may be listed as follows:

1. Strike mass movement speed directly correlated with the speed power, with the skilled athlete punch speed tested to average 8-10m/s in the final stage.

2. Strike mass that is generally weight-class-specific, albeit the weight is never invested in a strike in full. Thus a skilled kickboxer’s punch was tested to mobilize up to 30% of the body weight (at least the arm plus the shoulder girdle weight).

3. Kinematic chain stiffness directly correlated with the strike power. An ideal punch sequence, for instance, implies the fist being stiff at the final stage with the thumb pressed tight to the point finger and the hand strong fixed in the wrist. An ideal kick implies the kicking muscles being as stiff as possible at the contact moment. It should be mentioned that every strike sequence has its tension and relaxation phases. When the latter are tested to take up to 99% of the strike time, the whip effect of the strike is maximal.

4. Strike trajectory, with the kinematic energy of the striking hand/ foot fully invested in the contact point. The higher is the contact speed, the more is the strike power, with the striking chain being as stiff as possible at the contact moment. In case of a punch, the fist shall be lined up with the forearm and shoulder, with an exhale of 1/3 the total vital capacity at the contact moment.

5. Contact time which is known to inversely correlate with the strike power and ideally fall within the range of 14-18 milliseconds (ms). When the contact time comes to 30ms, it is rather a push than a punch. The contact time generally grows with the contact masses and the joints relaxation ratio.

6. Skill level directly correlated with the striking power for the reason that a skilled fighter is more effective and efficient in the strike control and physical resource mobilizing.

7. Functional asymmetry due to the natural difference in the arms/legs powers and controls. Thus a southpaw’s left-hand punch may be 40% more powerful than the right-hand one.

Conclusion. The test data were used to find the top-speed segments in an ideal strike sequence; the moment of the muscle relaxation in the strike sequence; correlation between the strike power and kinematic chain stiffness; and to profile the maximal ‘whip’ effect versus the passive sub-pushing strike. We believe that further research is needed to facilitate the striking power training aspects for competitive success.

References

  1. Ashmarin B.A. Teoriya i metodika pedagogicheskikh issledovaniy [Theory and methods of research in education]. Moscow, 1978, 223 p.
  2. Belykh S.I. Problemy sovershenstvovaniya podgotovki kikbokserov [Problems of kickboxer training improvement]. VI International Scientific Congress. Warsaw, 2002, pp. 56-67.
  3. Ivanov A.L. Kikboksing [Kickboxing]. 4th ed., rev., sup.. Kiev: Korbush publ., 2007, 320 p.
  4. Kalmykov E.V. Teoriya i metodika boksa [Theory and practice of boxing]. Moscow: Fizicheskaya kultura publ., 2009, 272 p.

Corresponding author: kf.physical_education@donnu.ru

Abstract

Lately in sport science special attention was given to the strike power training driven by the movement biomechanics in kickboxing. Objective of the study in this context was to use the process biomechanics analysis to identify the factors of influence on the strike power training. We applied for the study purposes special technical tools and test equipment; endurance exercises till refusal; weighted exercises; and the interval trainings and competitions. The study was run at the kickboxing and boxing clubs in the Donetsk Oblast where 25% of the Ukraine national kickboxing team come from. We used electromyograms and 16mmvideo captures to rate the strike speeds and powers. The test data were used to find the top-speed segments in an ideal strike sequence; the moment of the muscle relaxation in the strike sequence; correlation between the strike power and kinematic chain stiffness; and to profile the maximal ‘whip’ effect versus the passive sub-pushing strike.