RESUMO
BACKGROUND: The relationship between hip strength deficiency in various planes and musculoskeletal injuries within the movement system has been well-established in numerous studies. The present study sought to explore the relationships between hip strength and specific aspects of lower extremity running kinematics. METHODOLOGY: To achieve this objective, the three-dimensional running kinematics of 21 male elite middle-distance runners (mean age: 19.7 ± 1.2 years; mean experience 6.5 ± 1.0 years) were assessed using nine high-speed cameras on a treadmill at a speed of 16 km·h⻹. Concurrently, isokinetic hip strength was measured at a speed of 60 deg·s⻹ in both the dominant and non-dominant legs. The Pearson correlation coefficient and Paired Samples t-test were utilized. RESULTS: While no significant differences were found in several isokinetic strength measurements, notable differences in running kinematics were observed. Specifically, pelvic drop at midstance (MS) was significantly lower in the DL (5.79 ± 3.00°) compared to the NDL (8.71 ± 1.39°) with a large effect size (t=-4.04, p < 0.001, Cohen's d = 1.25). Additionally, knee adduction at maximum showed a moderate effect size difference, with the DL at 2.99 ± 1.13° and the NDL at 3.81 ± 1.76° (t=-2.74, p = 0.03, Cohen's d = 0.55). Results indicated a moderate to highly positive association between running knee adduction in the dominant leg and hip external rotation (r = 0.67, p < 0.05), concentric extension (r = 0.77, p < 0.05), and concentric abduction (r = 0.78, p < 0.05). Additionally, the running tibial external rotation angle in the dominant leg exhibited an inverse relationship with all strength measurements, with statistical significance observed only for concentric extension force (r=-0.68, p < 0.05). Furthermore, hip internal rotation force demonstrated a highly inverse correlation with foot pronation in the dominant leg (r=-0.70, p < 0.05) and anterior pelvic tilt in the non-dominant leg (r=-0.76, p < 0.05). CONCLUSIONS: These findings underscore the interrelation between hip strength and running kinematics, particularly on the dominant side. In light of these observations, it is imperative to consider hip strength exercises as integral components for correcting running kinematics. Coaches should also be mindful that kinematic deviations contributing to running injuries may manifest unilaterally or specifically in the dominant leg.
RESUMO
BACKGROUND: This study aimed to compare serum brain-derived neurotrophic factor (BDNF) levels "which contributes in both neuron development/regeneration" between combat sport braches, which requires high attention and concentration and can lead micro and macro brain trauma, and athleticism, which requires durability in competition. METHODS: The study design included 4 groups. Group 1 had sedentary participants, and group 2 athletes (middle and long runners) who exercised for two 2-hour daily training sessions 6 days a week. group 3 included boxers, and group 4 taekwondo fighters. We investigated changes in the blood BDNF levels of taekwondo fighters, boxers, and athletes before and after training and compared them among each other and with measurements of sedentary controls. RESULTS: All athletes had higher basal BDNF levels than sedentary participants. Boxers and taekwondo athletes had especially high basal BDNF levels. When we compared different sports branch each other Pre- and post- training BDNF values are ranked as follows: taekwondo > boxing > athletes > sedentary. In sport branches such as combat sports and athletes, serum BDNF levels have been demonstrated to be higher after training than before. In addition, serum BDNF levels were higher in taekwondo fighters and boxers than athletes. CONCLUSIONS: BDNF might have a role in the protection mechanism against brain damage or contributes in occurrence and maintenance of high attention and concentration especially among combat sports.
