• Electromyographical differences in the muscular activity of the Lumbopelvis and hip region between mid- and high-section Taekwondo turning kicks

      Smith, Grace; Radcliffe, Yana (University of Chester, 2013-09-30)
      This study aimed to compare the electromyographical (EMG) levels, timings and patterns of selected lumbopelvis and hip muscles between mid- and high-section Taekwondo turning kicks. Thirteen healthy elite (internationally competitive) Taekwondo athletes participated (age: 21.00 ± 3.00 years; mass: 72.89 ± 8.64 kg; stature: 1.79 ± 0.05 m). Subgroups included an ‘injury’ group (n = 6) with lumbopelvic region injury history, and a ‘no injury’ group (n = 7). Participants randomly performed 8 maximal dominant back leg mid- and high-section turning kicks. Surface EMG of the kicking and support leg external obliques (EO), gluteus maximus (GM), adductor longus (AL), and biceps femoris (BF) were analysed. Data were normalised to isometric maximum voluntary contractions (MVC). Paired-sampled t-tests were adopted for statistical analyses (p < 0.05). Overall, mid-section kicks resulted in significantly greater kicking leg mean GM and AL, peak GM EMG levels (p < 0.05), and shorter kick durations (p < 0.01) than high-section turning kicks. Times to peak EMG level results were inconclusive. Within the ‘injury’ subgroup, significantly greater peak loading phase support leg BF activity was observed during mid- compared to high-section turning kicks (p < 0.05). Effect sizes were large (r > 0.80). In conclusion, greater EMG activity was produced during mid- compared to high-section turning kicks, perhaps because of faster kicking velocities. In the ‘injury’ subgroup the support leg hamstrings and groin appeared vulnerable to injury due to high loading phase mid-section BF activity and / or kicking phase high-section BF activity, and poor coactivation of the GM and AL respectively. However, high inter-participant CV (> 0.80) suggests poor repeatability. Further research is needed to provide more valid conclusions.