Purpose: Although several studies investigated the effect of plyometric training on physical performance, there is a lack of clarity regarding the effectiveness of plyometric training or its moderator variables in youth female volleyball players. The primary aim of this study was to explore the effect of horizontal plyometric training on explosive stretch-shortening cycle hops and jumps in the vertical and horizontal directions in female post peak height velocity (PHV) volleyball players. The secondary aim was to assess the influence of participant and training related moderators on horizontal plyometric training in post-PHV volleyball players. Methods: A total of 23 post-PHV volleyball players participated in this 8-week intervention with horizontal plyometric exercises, twice a week. Pre-testing and post-testing included bilateral and unilateral vertical sub-maximal hopping, horizontal jumping and hopping, and a drop jump test. The effectiveness of the intervention was assessed using a paired t-test. The influence of internal moderators such as age, maturity and body mass and external moderators such as training volume were assessed using regression and correlation analysis. Results: An 8-week plyometric training improved sub-maximal hopping at 2.5 Hz left by 4.4%, bilateral sub-maximal hopping at 2.0 Hz by 9.5% and bilateral sub-maximal hopping at 2.2 Hz by 6.8% in post-PHV female volleyball players. Horizontal jumping and hopping, reactive strength index and other sub-maximal hopping conditions did not improve significantly. Body mass had a large moderating effect on vertical unilateral sub-maximal hopping at 2.5 Hz right (p = 0.010, η 2 = 0.314), vertical unilateral hopping at 3.0 Hz right (p = 0.035, η 2 = 0.170), and vertical unilateral hopping at 3.0 Hz left (p = 0.043, η 2 = 0.203). Training volume together with generalized joint hypermobility moderated right leg triple broad hop performance, whereas maturity and age did not moderate any variables. Conclusion: This study determined that 8 weeks of horizontal plyometric training can improve unilateral absolute leg stiffness in post-PHV female volleyball players, and this training effect can be moderated by body mass. Furthermore, the training effect on triple hopping performance on the right leg can be moderated by combined training volume with generalized joint hypermobility.
- Klíčová slova
- girls, maturation, plyometric exercises, reactive strength index, stiffness, youth sport,
- Publikační typ
- časopisecké články MeSH
Many hamstring injuries that occur during physical activity occur while the muscles are lengthening, during eccentric hamstring muscle actions. Opposite of these eccentric hamstring actions are concentric quadriceps actions, where the larger and likely stronger quadriceps straighten the knee. Therefore, to stabilize the lower limbs during movement, the hamstrings must eccentrically combat against the strong knee-straightening torque of the quadriceps. As such, eccentric hamstring strength expressed relative to concentric quadricep strength is commonly referred to as the "functional ratio" as most movements in sports require simultaneous concentric knee extension and eccentric knee flexion. To increase the strength, resiliency, and functional performance of the hamstrings, it is necessary to test and train the hamstrings at different eccentric speeds. The main purpose of this work is to provide instructions for measuring and interpreting eccentric hamstring strength. Techniques for measuring the functional ratio using isokinetic dynamometry are provided and sample data will be compared. Additionally, we briefly describe how to address hamstring strength deficiencies or unilateral strength differences using exercises that specifically focus on increasing eccentric hamstring strength.
- MeSH
- čtyřhlavý sval stehenní fyziologie MeSH
- dospělí MeSH
- kosterní svaly fyziologie MeSH
- lidé MeSH
- odporový trénink metody MeSH
- sporty fyziologie MeSH
- terapie cvičením metody MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- audiovizuální média MeSH
- časopisecké články MeSH
- práce podpořená grantem MeSH
The aim of the study was to describe and compare kinematics in two types of execution of attack hit, the goofy approach and regular approach. The research group consisted of players from the Czech Republic's top league (n = 12, age 28.0 ± 4.3 years, body height 196.6 ± 5.6 cm, body mass 89.7 ± 6.7 kg) divided into two groups according to the individual type of approach in the attack. Analysis of movement was performed by 3D kinematics video analysis, space coordinates were calculated by the DLT (Direct Linear Transformation) method together with interpretation software TEMA Bio 2.3 (Image Systems AB, Sweden). The players started their run-up from a distance of about 4 - 4.5 m from the net with similar maximal vertical velocity (2.91 - 2.96 m⋅s-1). The trajectory of players with goofy approach seemed to be convenient for the rotation of shoulders and hips in the moment of ball contact. Differences between both groups were observed. Players with a goofy approach had a longer flight phase compared to regularly approaching players.
- Klíčová slova
- 3D analysis, elite athletes, goofy approach, spike,
- Publikační typ
- časopisecké články MeSH
