@article{HelmPrieskeMuehlbaueretal.2020,
  author    = {Helm, Norman and Prieske, Olaf and M{\"u}hlbauer, Thomas and Kr{\"u}ger, Tom and Retzlaff, Matthias and Granacher, Urs},
  title     = {Associations between trunk muscle strength and judo-specific pulling performances in judo athletes},
  series = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation},
  volume    = {34},
  journal   = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation},
  number    = {1},
  publisher = {Thieme},
  address   = {Stuttgart},
  issn      = {0932-0555},
  doi       = {10.1055/a-0677-9608},
  pages     = {18 -- 27},
  year      = {2020},
  abstract  = {Background: Good trunk stability is an important prerequisite for the mobility of the upper and lower limbs during sport-specific movements. Therefore, trunk muscle strength may represent an important performance determinant for judo-specific movements. This study aimed at evaluating statistical correlations between trunk muscle strength and kinetic parameters during judo-specific pulling movements in judo players. Method: Twenty-one male sub-elite judo players aged 22 +/- 4 years with a mean training volume of 15 +/- 4 hours per week participated in this study. Peak isokinetic torque (PIT) of the trunk flexors (PITFlex), extensors (PITEx) and rotators (PITRot) was tested using an isokinetic dynamometer (IsoMed 2000). In addition, two kinetic parameters (mechanical work [W], maximal force [F-max]) were analysed using the judo-specific measurement and information system JERGo (c). For this purpose, athletes were asked to do their judo-specific pulling movements while standing and with a dynamic change of position (i.e. Morote-seoi-nage). Results: Regarding pulling movements while standing, significant correlations (0.62 <= r(P) <= 0.72) were found between isokinetic tests (PITFlex, PITEx, PITRot) and mechanical work during judo-specific movement. Further, significant correlations (0.59 <= r(P) <= 0.65) were detected between isokinetic tests (PITEx, PITRot) and judo-specific pulling movements (Fmax). Regarding pulling movements with a change of position, significant correlations (0.47 <= r(P) <= 0.88) were observed between isokinetics (PITFlex, PITEx, PITRot) and the kinetic pulling parameters (W, Fmax), irrespective of the examined arm. No significant differences in magnitude of correlation coefficients were found between PIT of the trunk flexors, extensors, and rotators and judo-specific movements. Further, the regression analysis indicated that PIT of the trunk extensors is the single best predictor for mechanical work during pulling movements while standing (46.9 \%). Trunk rotator PIT is the single best predictor for mechanical work during pulling movements with a change of position (69.4 \%). Conclusions: Findings from this study indicate that trunk muscle strength, particularly trunk rotator PIT is associated with kinetic pulling variables during pulling movements with a change of position. This implies that the development of trunk rotator strength could have an impact on pulling movements with a change of position (i.e. Morote-seoi-nage) in judo athletes.},
  language  = {de}
}
@article{HelmPrieskeMuehlbaueretal.2018,
  author    = {Helm, Norman and Prieske, Olaf and M{\"u}hlbauer, Thomas and Kr{\"u}ger, Tom and Granacher, Urs},
  title     = {Effects of judo-specific resistance training on kinetic and electromyographic parameters of pulling exercises in judo athletes},
  series = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation},
  volume    = {32},
  journal   = {Sportverletzung, Sportschaden : Grundlagen, Pr{\"a}vention, Rehabilitation},
  number    = {2},
  publisher = {Thieme},
  address   = {Stuttgart},
  issn      = {0932-0555},
  doi       = {10.1055/s-0043-122781},
  pages     = {134 -- 142},
  year      = {2018},
  abstract  = {Background In judo, rapid force production during pulling movements is an important component of athletic performance, which is why this capacity needs to be specifically exercised in judo. This study aimed at examining the effects of a judo-specific resistance training program using a judo ergometer system (PTJ) versus a traditional resistance training regime using a partner (PTP) on kinetics and muscle activity of judo-specific pulling exercises. Method Twenty-four male judo athletes (age: 22 +/- 4 years, training experience: 15 +/- 3 years) were randomly assigned to two groups. In a crossover design, the first group completed a 4-week PTJ followed by four weeks of PTP (each with three sessions per week). The second group conducted PTP prior to PTJ. PTJ and PTP were completed in addition to regular training. Before, 4 weeks and 8 weeks after training, tests were conducted to assess judo-specific pulling kinetics (i.e. maximal force, rate of force development [RFD], mechanical work) and electromyographic (EMG) shoulder/trunk muscle activity (i.e. biceps brachii muscle, deltoid muscle, trapezius muscle, erector spinae muscle) during pulling movements using a judo ergometer as well as unspecific strength tests (i.e. bench-pull, pull-ups). Results The statistical analysis revealed that in both groups ergometer pulling kinetics (p<.05, 0.83 <= d <= 1.77) and EMG activity (p<.05; 1.07 <= d <= 2.25) were significantly enhanced following 8 weeks of training. In addition, significantly larger gains in RFD, mechanical work, and EMG activity (i.e. deltoid muscle, erector spinae muscle, trapezius muscle) were found following PTJ compared to PTP (p<.05, 1.25 <= d <= 2.79). No significant enhancements were observed with the unspecific strength tests. Conclusion Our findings indicate that PTJ is superior to PTP regarding training-induced improvements in force production and muscle activity during judo-specific pulling exercises. Performance enhancements may partly be attributed to neural adaptations. No transfer effects on unspecific strength tests were detected following PTJ and PTP.},
  language  = {de}
}