TY - JOUR A1 - Hohmann, Andreas A1 - Fehr, Ulrich A1 - Kirsten, Robert A1 - Krüger, Tom T1 - Biomechanical analysis of the backstroke start technique in swimming Y1 - 2008 UR - http://www.ejournal-but.de SN - 1612-5770 ER - TY - GEN A1 - Prieske, Olaf A1 - Krüger, Tom A1 - Aehle, Markus A1 - Bauer, Erik A1 - Granacher, Urs T1 - Effects of Resisted Sprint Training and Traditional Power Training on Sprint, Jump, and Balance Performance in Healthy Young Adults BT - A Randomized Controlled Trial T2 - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe N2 - Power training programs have proved to be effective in improving components of physical fitness such as speed. According to the concept of training specificity, it was postulated that exercises must attempt to closely mimic the demands of the respective activity. When transferring this idea to speed development, the purpose of the present study was to examine the effects of resisted sprint (RST) vs. traditional power training (TPT) on physical fitness in healthy young adults. Thirty-five healthy, physically active adults were randomly assigned to a RST (n = 10, 23 ± 3 years), a TPT (n = 9, 23 ± 3 years), or a passive control group (n = 16, 23 ± 2 years). RST and TPT exercised for 6 weeks with three training sessions/week each lasting 45–60 min. RST comprised frontal and lateral sprint exercises using an expander system with increasing levels of resistance that was attached to a treadmill (h/p/cosmos). TPT included ballistic strength training at 40% of the one-repetition-maximum for the lower limbs (e.g., leg press, knee extensions). Before and after training, sprint (20-m sprint), change-of-direction speed (T-agility test), jump (drop, countermovement jump), and balance performances (Y balance test) were assessed. ANCOVA statistics revealed large main effects of group for 20-m sprint velocity and ground contact time (0.81 ≤ d ≤ 1.00). Post-hoc tests showed higher sprint velocity following RST and TPT (0.69 ≤ d ≤ 0.82) when compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to 4.5% for RST [90%CI: (−1.1%;10.1%), d = 1.23] and 2.6% for TPT [90%CI: (0.4%;4.8%), d = 1.59]. Additionally, ground contact times during sprinting were shorter following RST and TPT (0.68 ≤ d ≤ 1.09) compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to −6.3% for RST [90%CI: (−11.4%;−1.1%), d = 1.45) and −2.7% for TPT [90%CI: (−4.2%;−1.2%), d = 2.36]. Finally, effects for change-of-direction speed, jump, and balance performance varied from small-to-large. The present findings indicate that 6 weeks of RST and TPT produced similar effects on 20-m sprint performance compared with a passive control in healthy and physically active, young adults. However, no training-related effects were found for change-of-direction speed, jump and balance performance. We conclude that both training regimes can be applied for speed development. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 383 KW - specificity KW - sprinting KW - jumping KW - change-of-direction speed KW - balance Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-409645 IS - 383 ER - TY - JOUR A1 - Prieske, Olaf A1 - Krüger, Tom A1 - Aehle, Markus A1 - Bauer, Erik A1 - Granacher, Urs T1 - Effects of Resisted Sprint Training and Traditional Power Training on Sprint, Jump, and Balance Performance in Healthy Young Adults BT - A Randomized Controlled Trial JF - Frontiers in Physiology N2 - Power training programs have proved to be effective in improving components of physical fitness such as speed. According to the concept of training specificity, it was postulated that exercises must attempt to closely mimic the demands of the respective activity. When transferring this idea to speed development, the purpose of the present study was to examine the effects of resisted sprint (RST) vs. traditional power training (TPT) on physical fitness in healthy young adults. Thirty-five healthy, physically active adults were randomly assigned to a RST (n = 10, 23 ± 3 years), a TPT (n = 9, 23 ± 3 years), or a passive control group (n = 16, 23 ± 2 years). RST and TPT exercised for 6 weeks with three training sessions/week each lasting 45–60 min. RST comprised frontal and lateral sprint exercises using an expander system with increasing levels of resistance that was attached to a treadmill (h/p/cosmos). TPT included ballistic strength training at 40% of the one-repetition-maximum for the lower limbs (e.g., leg press, knee extensions). Before and after training, sprint (20-m sprint), change-of-direction speed (T-agility test), jump (drop, countermovement jump), and balance performances (Y balance test) were assessed. ANCOVA statistics revealed large main effects of group for 20-m sprint velocity and ground contact time (0.81 ≤ d ≤ 1.00). Post-hoc tests showed higher sprint velocity following RST and TPT (0.69 ≤ d ≤ 0.82) when compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to 4.5% for RST [90%CI: (−1.1%;10.1%), d = 1.23] and 2.6% for TPT [90%CI: (0.4%;4.8%), d = 1.59]. Additionally, ground contact times during sprinting were shorter following RST and TPT (0.68 ≤ d ≤ 1.09) compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to −6.3% for RST [90%CI: (−11.4%;−1.1%), d = 1.45) and −2.7% for TPT [90%CI: (−4.2%;−1.2%), d = 2.36]. Finally, effects for change-of-direction speed, jump, and balance performance varied from small-to-large. The present findings indicate that 6 weeks of RST and TPT produced similar effects on 20-m sprint performance compared with a passive control in healthy and physically active, young adults. However, no training-related effects were found for change-of-direction speed, jump and balance performance. We conclude that both training regimes can be applied for speed development. KW - specificity KW - sprinting KW - jumping KW - change-of-direction speed KW - balance Y1 - 2018 U6 - https://doi.org/10.3389/fphys.2018.00156 SN - 1664-042X VL - 9 SP - 1 EP - 10 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Prieske, Olaf A1 - Mühlbauer, Thomas A1 - Müller, Steffen A1 - Krüger, Tom A1 - Kibele, Armin A1 - Behm, David George A1 - Granacher, Urs T1 - Effects of surface instability on neuromuscular performance during drop jumps and landings JF - European journal of applied physiology N2 - The purpose of this study was to investigate the effects of surface instability on measures of performance and activity of leg and trunk muscles during drop jumps and landings. Drop jumps and landings were assessed on a force plate under stable and unstable (balance pad on top of the force plate) conditions. Performance measures (contact time, jump height, peak ground reaction force) and electromyographic (EMG) activity of leg and trunk muscles were tested in 27 subjects (age 23 +/- A 3 years) during different time intervals (preactivation phase, braking phase, push-off phase). The performance of drop jumps under unstable compared to stable conditions produced a decrease in jump height (9 %, p < 0.001, f = 0.92) and an increase in peak ground reaction force (5 %, p = 0.022, f = 0.72), and time for braking phase (12 %, p < 0.001, f = 1.25). When performing drop jumps on unstable compared to stable surfaces, muscle activity was reduced in the lower extremities during the preactivation, braking and push-off phases (11-25 %, p < 0.05, 0.48 a parts per thousand currency sign f a parts per thousand currency sign 1.23). Additionally, when landing on unstable compared to stable conditions, reduced lower limb muscle activities were observed during the preactivation phase (7-60 %, p < 0.05, 0.50 a parts per thousand currency sign f a parts per thousand currency sign 3.62). Trunk muscle activity did not significantly differ between the test conditions for both jumping and landing tasks. The present findings indicate that modified feedforward mechanisms in terms of lower leg muscle activities during the preactivation phase and/or possible alterations in leg muscle activity shortly after ground contact (i.e., braking phase) are responsible for performance decrements during jumping on unstable surfaces. KW - Stretch-shortening cycle KW - Trunk muscle strength KW - Jump height KW - Electromyography Y1 - 2013 U6 - https://doi.org/10.1007/s00421-013-2724-6 SN - 1439-6319 SN - 1439-6327 VL - 113 IS - 12 SP - 2943 EP - 2951 PB - Springer CY - New York ER - TY - JOUR A1 - Möller, Sebastian A1 - Kittel, René A1 - Krüger, Tom A1 - Srunk, Soeren A1 - Rosenblum, Michael A1 - Wick, Ditmar T1 - Movement profiles of the balance breaking (Kuzushi) of top judoka Y1 - 2008 SN - 978-3-8322-8390-2 ER - TY - JOUR A1 - Möller, Sebastian A1 - Kittel, René A1 - Krüger, Tom A1 - Sprunk, Sören A1 - Wick, Ditmar A1 - Rosenblum, Michael T1 - Movement profiles of the balance breaking (Kuzushi) of top judoka Y1 - 2009 SN - 978-3-8322-8390-2 ER - TY - JOUR A1 - Prieske, Olaf A1 - Mühlbauer, Thomas A1 - Krüger, Tom A1 - Kibele, Armin A1 - Behm, David George A1 - Granacher, Urs T1 - Role of the trunk during drop jumps on stable and unstable surfaces JF - European journal of applied physiology N2 - The present study investigated associations between trunk muscle strength, jump performance, and lower limb kinematics during drop jumps on stable and unstable surfaces. Next to this behavioral approach, correlations were also computed on a neuromuscular level between trunk and leg muscle activity during the same test conditions. Twenty-nine healthy and physically active subjects (age 23 +/- A 3 years) were enrolled in this study. Peak isokinetic torque (PIT) of the trunk flexors and extensors was assessed separately on an isokinetic device. In addition, tests included drop jumps (DJ) on a force plate under stable and unstable (i.e., balance pad on top of the force plate) surfaces. Lower limb kinematics as well as electromyographic activity of selected trunk and leg muscles were analyzed. Significant positive but small correlations (0.50 a parts per thousand currency sign r a parts per thousand currency sign 0.66, p < 0.05) were detected between trunk extensor PIT and athletic performance measures (i.e., DJ height, DJ performance index), irrespective of surface condition. Further, significant negative but small correlation coefficients were examined between trunk extensor PIT and knee valgus motion under stable and unstable surface conditions (-0.48 a parts per thousand currency sign r a parts per thousand currency sign -0.45, p < 0.05). In addition, significant positive but small correlations (0.45 a parts per thousand currency sign r a parts per thousand currency sign 0.68, p < 0.05) were found between trunk and leg muscle activity, irrespective of surface condition. Behavioral and neuromuscular data from this study indicate that, irrespective of the surface condition (i.e., jumping on stable or unstable ground), the trunk plays a minor role for leg muscle performance/activity during DJ. This implies only limited effects of trunk muscle strengthening on jump performance in the stretch-shortening cycle. KW - Core stability KW - Jump height KW - Knee valgus motion KW - Ground reaction force KW - Stretch-shortening cycle KW - Electromyography Y1 - 2015 U6 - https://doi.org/10.1007/s00421-014-3004-9 SN - 1439-6319 SN - 1439-6327 VL - 115 IS - 1 SP - 139 EP - 146 PB - Springer CY - New York ER - TY - JOUR A1 - Prieske, Olaf A1 - Mühlbauer, Thomas A1 - Krüger, Tom A1 - Kibele, A. A1 - Behm, David George A1 - Granacher, Urs T1 - Sex-Specific effects of surface instability on drop jump and landing biomechanics JF - International journal of sports medicine N2 - This study investigated sex-specific effects of surface instability on kinetics and lower extremity kinematics during drop jumping and landing. Ground reaction forces as well as knee valgus and flexion angles were tested in 14 males (age: 23 +/- 2 years) and 14 females (age: 24 +/- 3 years) when jumping and landing on stable and unstable surfaces. Jump height was found to be significantly lower (9 %, p < 0.001) when drop jumps were performed on unstable vs. stable surface. Significantly higher peak ground reaction forces were observed when jumping was performed on unstable vs. stable surfaces (5 %, p = 0.022). Regarding frontal plane kinematics during jumping and landing, knee valgus angles were higher on unstable compared to stable surfaces (1932 %, p < 0.05). Additionally, at the onset of ground contact during landings, females showed higher knee valgus angles than males (222 %, p = 0.027). Sagittal plane kinematics indicated significantly smaller knee flexion angles (6-35 %, p < 0.05) when jumping and landing on unstable vs. stable surfaces. During drop jumps and landings, women showed smaller knee flexion angles at ground contact compared to men (27-33 %, p < 0.05). These findings imply that knee motion strategies were modified by surface instability and sex during drop jumps and landings. KW - stretch-shortening cycle KW - ground reaction force KW - knee joint angle KW - injury risk Y1 - 2015 U6 - https://doi.org/10.1055/s-0034-1384549 SN - 0172-4622 SN - 1439-3964 VL - 36 IS - 1 SP - 75 EP - 81 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Krüger, Tom T1 - The effect of laterality on young athlets in flat water canoeing Y1 - 2009 UR - http://iospress.metapress.com/content/103163/ SN - 978-82-502-0420-1 ER - TY - JOUR A1 - Krüger, Tom T1 - The effect of laterality on young athlets in flat water canoeing Y1 - 2009 SN - 0959-3020 ER -