The strike force in combat sports strongly depends on the protective material's mechanical properties and energy absorption capacity. Therefore, this study aimed to estimate the effect of the protective layer thickness and repeated loading on the net force in a falling weight impact test. A falling 8-kg weight dropped from 15 cm, 25 cm, and 50 cm was used to simulate impact peak forces in an upper limb strike. Transfer linear regression functions were identified for three layers of different thickness (1.8 cm, 3.6 cm, and 5.4 cm) between the measured force and undamped force that would be measured if no protective layer was used. A decrease in damping performance under repetitive loading was assessed for the same amount of energy (30 J) absorbed by the specimens. There were 36 specimens examined in 126 tests. When the measuring apparatus was covered with one, two or three layers of Trocellen foam, the undamped force was approximately 2.8, 6.1, and 11.1 times higher, respectively (p < 0.05, R2 ≥ 0.95), than the force measured in the kinetic design. This allows researchers to select the number of layers according to the individual needs in terms of safety and injury prevention. A single layer of Trocellen foam used in this study may be insufficient to ensure the safety of athletes in upper limb strike experiments due to possible compaction of the foam structure for deformations exceeding 80% compression and forces exceeding 5 kN, although no injury was previously observed.

• Klíčová slova
• biomechanics, direct punch, elbow strike, falling weight impact test, mixed martial arts, palm strike,
• Publikační typ
• časopisecké články MeSH

Despite the recognized influence of body mass on combat techniques, the relationship between body segment mass (BSM) and combat moves remains unexplored. This study aimed to examine the relationship between the striking arm mass (SAM), kicking leg mass (KLM), and body mass (BM) and the dynamic forces of direct punch (DP), palm strike (PS), elbow strike (ES), front kick (FK), and countermovement jump (CMJ) performance. Sixteen male military cadets (22.3 ± 1.8 years, 181.4 ± 7.0 cm, 82.1 ± 8.5 kg) performed combat techniques, with their performance measured by using a force plate and their body segment mass assessed by dual-energy X-ray absorptiometry. Spearman's correlation analysis, the Wilcoxon test, and Cohen's d were applied. The results indicated the relationship between the KLM or BM and the FK impulse (r = 0.64, p = 0.01; r = 0.52, p = 0.04, respectively) and CMJ impact force (r = 0.80, p ≤ 0.01; r = 0.70, p ≤ 0.01, respectively). The FK peak and impact forces were moderately correlated with the CMJ jump height (r = 0.74, p ≤ 0.01; r = 0.77, p ≤ 0.01). Moreover, the FK peak force was significantly higher than that for DP, PS, and ES (p ≤ 0.01, d = 3.32; p ≤ 0.01, d = 1.6; and p = 0.013, d = 1.3, respectively). The highest relationship was found between the KLM and the FK impulse; however, the difference in variability explained by the KLM versus the body mass was only 12%. This suggests that knowledge of the BSM did not provide a significantly better estimate of the dynamic forces of the punches and FKs than the knowledge of the BM.

• Klíčová slova
• biomechanics, body mass, close combat, dynamic forces, martial art,
• Publikační typ
• časopisecké články MeSH

The evaluation of strike impact is important for optimal training, conditioning and tactical use. Therefore, the aim of this study was to evaluate ground and pound strikes, in terms of net force variability, across genders and performance levels. Eighty-one participants, professional men (n = 8, 37 ± 6 years, 195 ± 7 cm, 113 ± 27 kg), advanced men (n = 47, 26 ± 8 years, 180 ± 7 cm, 76 ± 11 kg), and advanced women (n = 26, 21 ± 1 years, 167 ± 6 cm, 61 ± 7 kg) performed three strikes from a kneeling position into a force plate on the ground. The elbow strike resulted in the highest impulse and the palm strike in the highest peak force for all three categories. These results support the recommendation that has previously been made to teach the palm strike to beginners and advanced tactical and combat athletes. The direct punch and elbow strike net force were characterized by a double peak curve, where the first peak variability explained 70.2-84% of the net force. The second peak was pronounced in professional men during elbow strikes, which explained 16% of net force variability. The strike type determines the impact net force and its characteristics, where palm strike is typical by highest peak impact tolerance and elbow strike by double force peak with high net force impulse.

• Klíčová slova
• direct punch, elbow strike, mix martial art, palm strike, self-defence,
• Publikační typ
• časopisecké články MeSH

Performance in strike combat sports is mostly evaluated through the values of the net force, acceleration, or speed to improve efficient training procedures and/or to assess the injury. There are limited data on the upper limb striking area, which can be a useful variable for contact pressure assessment. Therefore, the aim of this study was to determine the contact area of the upper limb in three different strike technique positions. A total of 38 men and 38 women (n = 76, 27.3 ± 8.5 years of age, 73.9 ± 13.8 kg of body weight, 173.3 ± 8.4 cm of body height) performed a static simulation of punch with a fist, palm strike, and elbow strike, where three segments of the right upper limb were scanned. The analysis of 684 images showed a correlation (r = 0.634) between weight and punch technique position in men and significant differences in elbow strike (p < 0.001) and palm strike (p < 0.0001) between women and men. In both groups, the palm demonstrated the largest area and the elbow the smallest one. These data may be used to evaluate strike contact pressure in future studies in forensic biomechanics and assessment of injury in combat sports and self-defense.

• Klíčová slova
• Mixed Martial Art, combat sports, direct punch, elbow strike, hand, injury, palm strike, self-defense,
• Publikační typ
• časopisecké články MeSH

Athletes of mixed martial arts use a ground and pound strategy with the strikes in the dominant ground position. The aim of this study was to compare the average peak force (Fpeak) among three punches and to estimate the probability of achieving a skull bone fracture force of 5.1 kN for each type of strike in male and female athletes. A total of 60 males and 31 females (26 ± 8 years, 75 ± 20 kg, 177 ± 11 cm) practicing professional self-defense at the advanced and professional levels performed 15 strikes on a force plate. The analyses of 1360 trials showed significant differences among the strikes Fpeak in females (p < 0.01) and males (p < 0.01). Straight punches had lower Fpeak than palm strikes and elbow strikes in both genders, and palm strikes had higher Fpeak than elbow strikes in females. No difference was observed between palm strikes and elbow strikes in males (p = 0.09). The ground and pound strikes resulted in higher impacts than previously reported strikes in the standing position. Male athletes can deliver a Fpeak above 5.1 kN with a probability of 36% with elbow and palm strikes. Such forces can cause head injury; therefore, the use of these strikes in competition should be carefully considered.

• Klíčová slova
• elbow strike, ground striking, head injuries, mixed martial arts, palm strike, straight punch, system of self-defense,
• MeSH
• bojové sporty * MeSH
• horní končetina fyziologie   MeSH
• lidé MeSH
• loketní kloub * MeSH
• sportovci MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH