Relationship between somatic build and kinematic indices of underwater undulatory swimming performed by young female swimmers

<i>Purpose</i>: The aim of this study was to determine the relationship between anthropometric indices and kinematic underwater undulatory swimming (UUS) variables among young female swimmers. <i>Methods</i>: The following parameters were determined in 34 participants (age 16.74 ± 0.70 years, World Aquatics score 561 ± 64): body height (<i>H</i>), mass (<i>M</i>) and fat percentage (<i>B_F</i> ), BMI, lengths of the lower limb (<i>L_L</i> ), thigh (<i>L_T</i> ), and calf (<i>L_C</i> ), circumferences of thigh (<i>C_T</i> ), maximum calf (<i>C_C</i> _MAX) and distal lower leg (<i>C_CDIS</i> ), skinfolds on the thigh (<i>F_T</i> ) and calf (<i>F_C</i> ), as well as foot length (<i>F_L</i> ) and width (<i>W_F</i> ), based on which an estimated foot surface area was calculated (<i>S_F</i> ). Using the kinematic analysis of UUS recordings, the following were determined: velocity (<i>v</i>), frequency ( <i>f</i> ), distance per cycle (DPC), amplitude of toe (<i>A</i>) and product of <i>A</i> × <i>f</i> (<i>I_Af</i> ). Pearson r correlation analysis was performed. <i>Results</i>: A relationship was observed between v and: <i>C_C</i> _MAX (<i>r</i> = 0.48), <i>C_CDIS</i> (<i>r</i> = 0.39) and <i>L_F</i> (<i>r</i> = 0.35). <i>I_Af</i> was correlated with: <i>C_CDIS</i> (<i>r</i> = 0.40), <i>C_C</i> _MAX (<i>r</i> = 0.39) and <i>M</i> (<i>r</i> = 0.35). A relationship was observed between <i>A</i> and <i>F</i> _T (<i>r</i> = 0.45) and <i>C</i> _T (<i>r</i> = 0.42), as well as DPC with <i>F_T</i> (0.40) and <i>C_C</i> _MAX (0.37). <i>Conclusions</i>: The results indicate that the somatic structure has a small effect on the effectiveness and kinematic indices of UUS among young female swimmers.