## 3 Results  
The difference in body weight between competitors was only 4 kg. An even greater difference was in body height and was 10 cm in favor of [PERSON]. Both measurements significantly differentiated hurdlers in terms of a measure of body fat (the ratio of the weight of the body in kilograms to the square of its height in meters), which was 1.21 in favor of [PERSON] (Table 1). The time difference between those two world records is 0.04s. [PERSON] set his world record at the age of 26 and [PERSON] at the age of 22. The age difference between competitors on the day of the experiment was approximately 10 years in favor of [PERSON], and [PERSON] obtained a better result by 0.47s in the 110 m performance.  
Based on biomechanical analyses (Table 2), the following results were obtained: [PERSON]'s total stride length was 3.66 m, and the stride was completed in 0.33 s, while [PERSON]'s stride length was 3.67 m, and it was slightly slower, lasting 0.36 s. During hurdle clearance, [PERSON] reached the highest COM point at 1.38 m (0.32 m above the height of the hurdle), which corresponded to 72.2% of his body height. [PERSON] reached the COM trajectory point at 1.52 m (0.45 m above the hurdle height), which was 83.4% of his height. The difference between the lowest COM point in the eccentric phase of the take-off was 1.11 m for [PERSON] and 0.95 m for [PERSON]; and the highest COM point during the flight phase was 1.387 m for [PERSON] and 1.517 m for [PERSON]. The height of the COM at the end of the concentric phase of take-off for [PERSON] was 1.24 m and 1.08 m for [PERSON].  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Variables** & **[PERSON]** & **[PERSON]** & **Difference** & \(\Delta\) **(\%)** \\ \hline Horizontal velocity 4 H–5 H (m/s) & 9.14 & 9.18 & 0.04 & 0.43 \\  & \multicolumn{3}{c}{Take-off (braking phase)} & & \\ Horizontal velocity of COM (m/s) & 8.81 & 8.70 & 0.11 & 1.25 \\ Vertical velocity of COM m/s & –0.43 & –0.70 & 0.37 & 62.79 \\ Velocity resultant of COM (m/s & 8.82 & 8.73 & 0.09 & 1.03 \\ Height of COM (m) & 0.95 & 1.11 & 0.16 & 16.84 \\ Foot to hurdle distance (m) & 2.09 & 2.43 & 0.34 & 16.26 \\  & \multicolumn{3}{c}{Take-off (propulsion phase)} & & \\ Horizontal velocity of COM (m/s) & 9.11 & 9.00 & 0.11 & 1.21 \\ Vertical velocity of COM (m/s) & 2.35 & 1.80 & 0.55 & 23.41 \\ Velocity resultant of COM (m/s) & 9.41 & 9.18 & 0.23 & 2.45 \\ Height of COM (m) & 1.08 & 1.24 & 0.16 & 14.81 \\ Push-off angle (\({}^{\circ}\)) & 72.9 & 78.7 & 5.80 & 7.95 \\ Contact time (s) & 0.10 & 0.10 & 0.0 & 0.0 \\  & \multicolumn{3}{c}{Flight} & & \\ Flight time (s) & 0.36 & 0.33 & 0.03 & 8.34 \\ Height of COM above the hurdle (m) & 0.45 & 0.32 & 0.13 & 28.89 \\ Maximal height COM (m) & 1.44 & 1.52 & 0.08 & 5.55 \\  & \multicolumn{3}{c}{Landing (braking phase)} & & \\ Horizontal velocity of COM m/s & 8.77 & 8.80 & 0.03 & 0.34 \\ Vertical velocity of COM (m/s) & –1.02 & –1.00 & –0.02 & 1.97 \\ Velocity resultant of COM (m/s) & 8.84 & 8.86 & 0.02 & 0.22 \\ Height of COM (m) & 1.15 & 1.30 & 0.15 & 13.04 \\ Foot to hurdle distance (m) & 1.58 & 1.23 & 0.35 & 22.16 \\  & \multicolumn{3}{c}{Landing (propulsion phase)} & & \\ Horizontal velocity of COM (m/s) & 8.41 & 9.35 & 1.06 & 11.17 \\ Vertical velocity of COM (m/s) & –1.32 & –1.00 & –0.32 & 24.25 \\ Velocity resultant of COM (m/s) & 8.53 & 9.40 & 1.13 & 10.19 \\ Height of COM (m) & 1.06 & 1.23 & 0.17 & 16.03 \\ Contact time (s) & 0.08 & 0.07 & 0.01 & 12.50 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Biomechanical variables of the clearance of the fifth hurdle.