TY - JOUR A1 - Mühlbauer, Thomas A1 - Pabst, Jan A1 - Granacher, Urs A1 - Buesch, Dirk T1 - Validity of the jump-and-reach test in subelite adolescent handball players JF - Journal of strength and conditioning research : the research journal of the NSCA KW - Vertec device KW - Optojump system KW - vertical jump height KW - field test KW - athlete testing KW - region/point elastic gym floor Y1 - 2017 U6 - https://doi.org/10.1519/JSC.0000000000001607 SN - 1064-8011 SN - 1533-4287 VL - 31 SP - 1282 EP - 1289 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Helm, Norman A1 - Prieske, Olaf A1 - Mühlbauer, Thomas A1 - Krüger, Tom A1 - Chaabene, Helmi A1 - Granacher, Urs T1 - Validation of a new judo-specific ergometer system in male elite and sub-elite athletes JF - Journal of sports science & medicine N2 - Our experimental approach included two studies to determine discriminative validity and test-retest reliability (study 1) as well as ecological validity (study 2) of a judo ergometer system while performing judo-specific movements. Sixteen elite (age: 23 +/- 3 years) and 11 sub-elite (age: 16 +/- 1 years) athletes participated in study 1 and 14 male sub-elite judo athletes participated in study 2. Discriminative validity and test-retest reliability of sport-specific parameters (mechanical work, maximal force) were assessed during pulling movements with and without tsukuri (kuzushi). Ecological validity of muscle activity was determined by performing pulling movements using the ergometer without tsukuri and during the same movements against an opponent. In both conditions, electromyographic activity of trunk (e.g., m. erector spinae) and upper limb muscles (e.g., m. biceps brachii) were assessed separately for the lifting and pulling arm. Elite athletes showed mostly better mechanical work, maximal force, and power (0.12 <= d <= 1.80) compared with sub-elite athletes. The receiver operating characteristic analysis revealed acceptable validity of the JERGo(C) system to discriminate athletes of different performance levels predominantly during kuzushi without tsukuri (area under the curve = 0.27-0.90). Moreover, small-to-medium discriminative validity was found to detect meaningful performance changes for mechanical work and maximal force. The JERGo(C) system showed small-to-high relative (ICC = 0.37-0.92) and absolute reliability (SEM = 10.8-18.8%). Finally, our analyses revealed acceptable correlations (r = 0.41-0.88) between muscle activity during kuzushi performed with the JERGo(C) system compared with a judo opponent. Our findings indicate that the JERGo(C) system is a valid and reliable test instrument for the assessment and training of judo-specific pulling kinetics particularly during kuzushi movement without tsukuri. KW - Judo-specific pulling movement KW - work KW - force KW - muscle activity KW - reliability Y1 - 2018 SN - 1303-2968 VL - 17 IS - 3 SP - 465 EP - 474 PB - Department of Sports Medicine, Medical Faculty of Uludag University CY - Bursa ER - TY - JOUR A1 - Granacher, Urs A1 - Prieske, Olaf A1 - Majewski, M. A1 - Büsch, Dirk A1 - Mühlbauer, Thomas T1 - The Role of Instability with Plyometric Training in Sub-elite Adolescent Soccer Players JF - International journal of sports medicine N2 - The purpose of this study was to investigate the effects of plyometric training on stable (SPT) vs. highly unstable surfaces (IPT) on athletic performance in adolescent soccer players. 24 male sub-elite soccer players (age: 15 +/- 1 years) were assigned to 2 groups performing plyometric training for 8 weeks (2 sessions/week, 90min each). The SPT group conducted plyometrics on stable and the IPT group on unstable surfaces. Tests included jump performance (countermovement jump [CMJ] height, drop jump [DJ] height, DJ performance index), sprint time, agility and balance. Statistical analysis revealed significant main effects of time for CMJ height (p<0.01, f=1.44), DJ height (p<0.01, f=0.62), DJ performance index (p<0.05, f=0.60), 0-10-m sprint time (p<0.05, f=0.58), agility (p<0.01, f=1.15) and balance (p<0.05, 0.46f1.36). Additionally, a Training groupxTime interaction was found for CMJ height (p<0.01, f=0.66) in favor of the SPT group. Following 8 weeks of training, similar improvements in speed, agility and balance were observed in the IPT and SPT groups. However, the performance of IPT appears to be less effective for increasing CMJ height compared to SPT. It is thus recommended that coaches use SPT if the goal is to improve jump performance. KW - strength KW - jump KW - speed KW - agility KW - balance Y1 - 2015 U6 - https://doi.org/10.1055/s-0034-1395519 SN - 0172-4622 SN - 1439-3964 VL - 36 IS - 5 SP - 386 EP - 394 PB - Thieme CY - Stuttgart 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 - Mühlbauer, Thomas A1 - Gollhofer, Albert A1 - Granacher, Urs T1 - Sex-related effects in strength training during adolescence a pilot study JF - Perceptual & motor skills N2 - The objective was to investigate the effects of high-velocity strength training on isometric strength of the leg extensors and jump height in female and male adolescents. Twenty-eight students (13 boys, 15 girls) ages 16 to 17 years participated in this study and were assigned to either a strength training group or a control group. Strength training was conducted over 8 weeks (2 times per week). Pre- and post-training tests included the measurements of maximal isometric force and rate of force development of the leg extensors as well as countermovement jump height. Both girls (effect size = 1.37) and boys (effect size = 0.61) showed significant improvements in jump height. However, significant increases in maximal isometric force (effect size = 1.85) and rate of force development (effect size = 2.23) were found only in girls. In female and male adolescents, high-velocity strength training is an effective training regimen that produced improvements in countermovement jump height in both sexes but higher gains in maximal isometric force and rate of force development in girls. Y1 - 2012 U6 - https://doi.org/10.2466/06.10.30.PMS.115.6.953-968 SN - 0031-5125 VL - 115 IS - 3 SP - 953 EP - 968 PB - Sage Publ. CY - Missoula 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 - Granacher, Urs A1 - Lacroix, Andre A1 - Roettger, Katrin A1 - Gollhofer, Albert A1 - Mühlbauer, Thomas T1 - Relationships between trunk muscle strength, spinal mobility, and balance performance in older adults JF - Journal of aging and physical activity N2 - This study investigated associations between variables of trunk muscle strength (TMS), spinal mobility, and balance in seniors. Thirty-four seniors (sex: 18 female, 16 male; age: 70 +/- 4 years; activity level: 13 +/- 7 hr/week) were tested for maximal isometric strength (MIS) of the trunk extensors, flexors, lateral flexors, rotators, spinal mobility, and steady-state, reactive, and proactive balance. Significant correlations were detected between all measures of TMS and static steady-state balance (r = .43.57, p < .05). Significant correlations were observed between specific measures of TMS and dynamic steady-state balance (r = .42.55, p < .05). No significant correlations were found between all variables of TMS and reactive/proactive balance and between all variables of spinal mobility and balance. Regression analyses revealed that TMS explains between 1-33% of total variance of the respective balance parameters. Findings indicate that TMS is related to measures of steady-state balance which may imply that TMS promoting exercises should be integrated in strength training for seniors. KW - elderly KW - core KW - gait KW - postural balance KW - force KW - physical performance Y1 - 2014 U6 - https://doi.org/10.1123/JAPA.2013-0108 SN - 1063-8652 SN - 1543-267X VL - 22 IS - 4 SP - 490 EP - 498 PB - Human Kinetics Publ. CY - Champaign ER - TY - JOUR A1 - Mühlbauer, Thomas A1 - Besemer, Carmen A1 - Wehrle, Anja A1 - Gollhofer, Albert A1 - Granacher, Urs T1 - Relationship between strength; balance and mobility in children aged 7-10 years JF - Gait & posture N2 - The purpose of this study was to investigate the association between variables of lower extremity muscle strength, balance, and mobility assessed under various task conditions. Twenty-one healthy children (mean age: 9 +/- 1 years) were tested for their isometric and dynamic strength as well as for their steady-state, proactive, and reactive balance and mobility. Balance and mobility tests were conducted under single and dual task conditions. Significant positive correlations were detected between measures of isometric and dynamic leg muscle strength. Hardly any significant associations were observed between variables of strength and balance/mobility and between measures of steady-state, proactive, and reactive balance. Additionally, no significant correlations were detected between balance/mobility tests performed under single and dual task conditions. The predominately non-significant correlations between different balance components and mobility imply that balance and mobility performance is task specific. Further, strength and balance/mobility as well as balance under single and dual task conditions seem to be independent of each other and may have to be tested and trained complementarily. KW - Steady-state balance KW - Proactive/reactive balance KW - Maximal isometric force KW - Jumping height KW - Single/dual tasking KW - Cognitive/motor interference Y1 - 2013 U6 - https://doi.org/10.1016/j.gaitpost.2012.06.022 SN - 0966-6362 VL - 37 IS - 1 SP - 108 EP - 112 PB - Elsevier CY - Clare ER - TY - JOUR A1 - Mühlbauer, Thomas A1 - Besemer, Carmen A1 - Wehrle, Anja A1 - Gollhofer, Albert A1 - Granacher, Urs T1 - Relationship between strength, power and balance performance in seniors JF - Gerontology N2 - Background: Deficits in strength, power and balance represent important intrinsic risk factors for falls in seniors. Objective: The purpose of this study was to investigate the relationship between variables of lower extremity muscle strength/power and balance, assessed under various task conditions. Methods: Twenty-four healthy and physically active older adults (mean age: 70 8 5 years) were tested for their isometric strength (i.e. maximal isometric force of the leg extensors) and muscle power (i.e. countermovement jump height and power) as well as for their steady-state (i.e. unperturbed standing, 10-meter walk), proactive (i.e. Timed Up & Go test, Functional Reach Test) and reactive (i.e. perturbed standing) balance. Balance tests were conducted under single (i.e. standing or walking alone) and dual task conditions (i.e. standing or walking plus cognitive and motor interference task). Results: Significant positive correlations were found between measures of isometric strength and muscle power of the lower extremities (r values ranged between 0.608 and 0.720, p < 0.01). Hardly any significant associations were found between variables of strength, power and balance (i.e. no significant association in 20 out of 21 cases). Additionally, no significant correlations were found between measures of steady-state, proactive and reactive balance or balance tests performed under single and dual task conditions (all p > 0.05). Conclusion: The predominately nonsignificant correlations between different types of balance imply that balance performance is task specific in healthy and physically active seniors. Further, strength, power and balance as well as balance under single and dual task conditions seem to be independent of each other and may have to be tested and trained complementarily. KW - Steady-state balance KW - Proactive/reactive balance KW - Force production KW - Single/dual tasking KW - Cognitive/motor interference Y1 - 2012 U6 - https://doi.org/10.1159/000341614 SN - 0304-324X VL - 58 IS - 6 SP - 504 EP - 512 PB - Karger CY - Basel ER - TY - JOUR A1 - Golle, Kathleen A1 - Mühlbauer, Thomas A1 - Wick, Ditmar A1 - Granacher, Urs T1 - Physical Fitness Percentiles of German Children Aged 9–12 Years BT - findings from a Longitudinal Study JF - PLoS ONE N2 - Background Generating percentile values is helpful for the identification of children with specific fitness characteristics (i.e., low or high fitness level) to set appropriate fitness goals (i.e., fitness/health promotion and/or long-term youth athlete development). Thus, the aim of this longitudinal study was to assess physical fitness development in healthy children aged 9–12 years and to compute sex- and age-specific percentile values. Methods Two-hundred and forty children (88 girls, 152 boys) participated in this study and were tested for their physical fitness. Physical fitness was assessed using the 50-m sprint test (i.e., speed), the 1-kg ball push test, the triple hop test (i.e., upper- and lower- extremity muscular power), the stand-and-reach test (i.e., flexibility), the star run test (i.e., agility), and the 9-min run test (i.e., endurance). Age- and sex-specific percentile values (i.e., P10 to P90) were generated using the Lambda, Mu, and Sigma method. Adjusted (for change in body weight, height, and baseline performance) age- and sex-differences as well as the interactions thereof were expressed by calculating effect sizes (Cohen’s d). Results Significant main effects of Age were detected for all physical fitness tests (d = 0.40–1.34), whereas significant main effects of Sex were found for upper-extremity muscular power (d = 0.55), flexibility (d = 0.81), agility (d = 0.44), and endurance (d = 0.32) only. Further, significant Sex by Age interactions were observed for upper-extremity muscular power (d = 0.36), flexibility (d = 0.61), and agility (d = 0.27) in favor of girls. Both, linear and curvilinear shaped curves were found for percentile values across the fitness tests. Accelerated (curvilinear) improvements were observed for upper-extremity muscular power (boys: 10–11 yrs; girls: 9–11 yrs), agility (boys: 9–10 yrs; girls: 9–11 yrs), and endurance (boys: 9–10 yrs; girls: 9–10 yrs). Tabulated percentiles for the 9-min run test indicated that running distances between 1,407–1,507 m, 1,479–1,597 m, 1,423–1,654 m, and 1,433–1,666 m in 9- to 12-year-old boys and 1,262–1,362 m, 1,329–1,434 m, 1,392–1,501 m, and 1,415–1,526 m in 9- to 12-year-old girls correspond to a “medium” fitness level (i.e., P40 to P60) in this population. Conclusions The observed differences in physical fitness development between boys and girls illustrate that age- and sex-specific maturational processes might have an impact on the fitness status of healthy children. Our statistical analyses revealed linear (e.g., lower-extremity muscular power) and curvilinear (e.g., agility) models of fitness improvement with age which is indicative of timed and capacity-specific fitness development pattern during childhood. Lastly, the provided age- and sex-specific percentile values can be used by coaches for talent identification and by teachers for rating/grading of children’s motor performance. Y1 - 2015 U6 - https://doi.org/10.1371/journal.pone.0142393 SN - 1932-6203 VL - 10 IS - 11 PB - Public Library of Science CY - Lawrence, Kan. ER -