TY - JOUR A1 - Müller, Jörg A1 - Boch, Steffen A1 - Blaser, Steffen A1 - Fischer, Markus A1 - Prati, Daniel T1 - Effects of forest management on bryophyte communities on deadwood JF - Nova Hedwigia : Zeitschrift für Kryptogamenkunde N2 - Epixylic bryophytes are important components of forest vegetation but are currently endangered by increment of wood harvest and intensive forest management. In this paper we present a study about the relationship between forest management, deadwood abundance, deadwood attributes and species richness of epixylic bryophytes on 30 plots comprising three forest types (managed coniferous, managed deciduous and unmanaged deciduous forests) in three regions in Germany. Additionally we analyzed the relations between deadwood attributes (wood species, decay, deadwood type, size) and bryophytes on deadwood items (n = 799) and calculated species interaction networks of wood species and bryophytes. Overall, species richness of epixylic bryophytes was positively related to deadwood abundance and diversity. The mean deadwood abundance was lowest in unmanaged forests (9.7 m(3) ha(-1)) compared with 15.0 m(3) ha(-1) in managed deciduous and 25.1 m(3) ha(-1) in managed coniferous forests. Accordingly, epixylic bryophyte species richness per plot increased from 7 species per 400 m(2) in unmanaged, 10 in managed deciduous and 16 in managed coniferous forests. The interaction network provided evidence of importance of tree-species diversity for bryophyte diversity and the relevance of particular wood species for rare bryophytes. Generally, the results demonstrate a considerable lack of deadwood in all forest types, even in unmanaged forests. Species richness of epixylic bryophytes was strongly limited by available substrates within the observed deadwood abundance ranging up to only 60 m(3) ha(-1). Altogether, this suggests a high demand to increase both abundance and diversity of deadwood in forests. KW - Coarse woody debris KW - cryptogams KW - deadwood KW - species interaction network KW - wood harvest Y1 - 2015 U6 - https://doi.org/10.1127/nova_hedwigia/2015/0242 SN - 0029-5035 VL - 100 IS - 3-4 SP - 423 EP - 438 PB - Cramer CY - Stuttgart ER - TY - JOUR A1 - Müller, Juliane A1 - Hadzic, Miralem A1 - Mugele, Hendrik A1 - Stoll, Josefine A1 - Müller, Steffen A1 - Mayer, Frank T1 - Effect of high-intensity perturbations during core-specific sensorimotor exercises on trunk muscle activation JF - Journal of biomechanics N2 - Core-specific sensorimotor exercises are proven to enhance neuromuscular activity of the trunk. However, the influence of high-intensity perturbations on training efficiency is unclear within this context. Sixteen participants (29 +/- 2 yrs; 175 +/- 8 cm; 69 +/- 13 kg) were prepared with a 12-lead bilateral trunk EMG. Warm-up on a dynamometer was followed by maximum voluntary isometric trunk (flex/ext) contraction (MVC). Next, participants performed four conditions for a one-legged stance with hip abduction on a stable surface (HA) repeated randomly on an unstable surface (HAP), on a stable surface with perturbation (HA + P), and on an unstable surface with perturbation (HAP + P). Afterwards, bird dog (BD) was performed under the same conditions (BD, BDP, BD + P, BDP + P). A foam pad under the foot (HA) or the knee (BD) was used as an unstable surface. Exercises were conducted on a moveable platform. Perturbations (ACC 50 m/sec(2);100 ms duration;10rep.) were randomly applied in the anterior-posterior direction. The root mean square (RMS) normalized to MVC (%) was calculated (whole movement cycle). Muscles were grouped into ventral right and left (VR;VL), and dorsal right and left (DR;DL). Ventral Dorsal and right-left ratios were calculated (two way repeated-measures ANOVA;alpha = 0,05). Amplitudes of all muscle groups in bird dog were higher compared to hip abduction (p <= 0.0001; Range: BD: 14 +/- 3% (BD;VR) to 53 +/- 4%; HA: 7 +/- 2% (HA;DR) to 16 +/- 4% (HA;DR)). EMG-RMS showed significant differences (p < 0.001) between conditions and muscle groups per exercise. Interaction effects were only significant for HA (p = 0.02). No significant differences were present in EMG ratios (p > 0.05). Additional high-intensity perturbations during core-specific sensorimotor exercises lead to increased neuromuscular activity and therefore higher exercise intensities. However, the beneficial effects on trunk function remain unclear. Nevertheless, BD is more suitable to address trunk muscles. KW - Split-belt treadmill KW - EMG KW - Core stability KW - MiSpEx Y1 - 2017 U6 - https://doi.org/10.1016/j.jbiomech.2017.12.013 SN - 0021-9290 SN - 1873-2380 VL - 70 SP - 212 EP - 218 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Müller, Juliane A1 - Engel, Tilman A1 - Kopinski, Stephan A1 - Mayer, Frank A1 - Müller, Steffen T1 - Neuromuscular trunk activation patterns in back pain patients during one-handed lifting JF - World journal of orthopedics N2 - AIM To analyze neuromuscular activity patterns of the trunk in healthy controls (H) and back pain patients (BPP) during one-handed lifting of light to heavy loads. METHODS RESULTS Seven subjects (3m/4f; 32 +/- 7 years; 171 +/- 7 cm; 65 +/- 11 kg) were assigned to BPP (pain grade >= 2) and 36 (13m/23f; 28 +/- 8 years; 174 +/- 10 cm; 71 +/- 12 kg) to H (pain grade <= 1). H and BPP did not differ significantly in anthropometrics (P > 0.05). All subjects were able to lift the light and middle loads, but 57% of BPP and 22% of H were not able to lift the heavy load (all women) chi(2) analysis revealed statistically significant differences in task failure between H vs BPP (P = 0.03). EMG-RMS ranged from 33% +/- 10%/30% +/- 9% (DL, 1 kg) to 356% +/- 148%/283% +/- 80% (VR, 20 kg) in H/BPP with no statistical difference between groups regardless of load (P > 0.05). However, the EMG-RMS of the VR was greatest in all lifting tasks for both groups and increased with heavier loads. CONCLUSION Heavier loading leads to an increase (2-to 3-fold) in trunk muscle activity with comparable patterns. Heavy loading (20 kg) leads to task failure, especially in women with back pain. KW - Lifting KW - Core KW - Trunk KW - EMG KW - MISPEX Y1 - 2016 U6 - https://doi.org/10.5312/wjo.v8.i2.142 SN - 2218-5836 VL - 8 IS - 2 SP - 142 EP - 148 PB - Baishideng Publishing Group CY - Pleasanton ER - TY - JOUR A1 - Müller, Steffen A1 - Müller, Juliane A1 - Stoll, Josefine A1 - Prieske, Olaf A1 - Cassel, Michael A1 - Mayer, Frank T1 - Incidence of back pain in adolescent athletes BT - a prospective study JF - BMC sports science, medicine & rehabilitation N2 - Background Recently, the incidence rate of back pain (BP) in adolescents has been reported at 21%. However, the development of BP in adolescent athletes is unclear. Hence, the purpose of this study was to examine the incidence of BP in young elite athletes in relation to gender and type of sport practiced. Methods Subjective BP was assessed in 321 elite adolescent athletes (m/f 57%/43%; 13.2 ± 1.4 years; 163.4 ± 11.4 cm; 52.6 ± 12.6 kg; 5.0 ± 2.6 training yrs; 7.6 ± 5.3 training h/week). Initially, all athletes were free of pain. The main outcome criterion was the incidence of back pain [%] analyzed in terms of pain development from the first measurement day (M1) to the second measurement day (M2) after 2.0 ± 1.0 year. Participants were classified into athletes who developed back pain (BPD) and athletes who did not develop back pain (nBPD). BP (acute or within the last 7 days) was assessed with a 5-step face scale (face 1–2 = no pain; face 3–5 = pain). BPD included all athletes who reported faces 1 and 2 at M1 and faces 3 to 5 at M2. nBPD were all athletes who reported face 1 or 2 at both M1 and M2. Data was analyzed descriptively. Additionally, a Chi2 test was used to analyze gender- and sport-specific differences (p = 0.05). Results Thirty-two athletes were categorized as BPD (10%). The gender difference was 5% (m/f: 12%/7%) but did not show statistical significance (p = 0.15). The incidence of BP ranged between 6 and 15% for the different sport categories. Game sports (15%) showed the highest, and explosive strength sports (6%) the lowest incidence. Anthropometrics or training characteristics did not significantly influence BPD (p = 0.14 gender to p = 0.90 sports; r2 = 0.0825). Conclusions BP incidence was lower in adolescent athletes compared to young non-athletes and even to the general adult population. Consequently, it can be concluded that high-performance sports do not lead to an additional increase in back pain incidence during early adolescence. Nevertheless, back pain prevention programs should be implemented into daily training routines for sport categories identified as showing high incidence rates. KW - Pain occurrence KW - Young athletes KW - Injury KW - Training volume Y1 - 2016 U6 - https://doi.org/10.1186/s13102-016-0064-7 SN - 2052-1847 VL - 8 PB - BioMed Central CY - London ER - TY - JOUR A1 - Müller, Steffen A1 - Stoll, Josefine A1 - Müller, Juliane A1 - Mayer, Frank T1 - Validity of isokinetic trunk measurements with respect to healthy adults, athletes and low back pain patients JF - Isokinetics and exercise science : official journal of the European Isokinetic Society N2 - Background: Isokinetic measurements are widely used to assess strength capacity in a clinical or research context. Nevertheless, the validity of isokinetic measures for identifying strength deficits and the evaluation of therapeutic process regarding different pathologies is yet to be established. Therefore, the purpose of this review is to evaluate the validity of isokinetic measures in a specific case: that of muscular capacity in low back pain (LBP). Methods: A literature search (PubMed; ISI Web of Knowledge; The Cochrane Library) covering the last 10 years was performed. Relevant papers regarding isokinetic trunk strength measures in healthy and patients with low back pain (PLBP) were searched. Peak torque values [Nm] and peak torque normalized to body weight [Nm/kg BW] were extracted for healthy and PLBP. Ranked mean values across studies were calculated for the concentric peak torque at 60 degrees/s as well as the flexion/extension (F/E) ratio. Results: 34 publications (31 flexion/extension; 3 rotation) were suitable for reporting detailed isokinetic strength measures in healthy or LBP (untrained adults, adolescents, athletes). Adolescents and athletes were different compared to normal adults in terms of absolute trunk strength values and the F/E ratio. Furthermore, isokinetic measures evaluating therapeutic process and isokinetic rehabilitation training were infrequent in literature (8 studies). Conclusion: Isokinetic measurements are valid for measuring trunk flexion/extension strength and F/E ratio in athletes, adolescents and (untrained) adults with/without LBP. The validity of trunk rotation is questionable due to a very small number of publications whereas no reliable source regarding lateral flexion could be traced. Therefore, isokinetic dynamometry may be utilized for identifying trunk strength deficits in healthy adults and PLBP. KW - Isokinetic KW - validity KW - low back pain KW - peak torque KW - trunk Y1 - 2012 U6 - https://doi.org/10.3233/IES-2012-00482 SN - 0959-3020 VL - 20 IS - 4 SP - 255 EP - 266 PB - IOS Press CY - Amsterdam ER - TY - GEN A1 - Müller, Steffen A1 - Müller, Juliane A1 - Stoll, Josefine A1 - Prieske, Olaf A1 - Cassel, Michael A1 - Mayer, Frank T1 - Incidence of back pain in adolescent athletes BT - a prospective study N2 - Background Recently, the incidence rate of back pain (BP) in adolescents has been reported at 21%. However, the development of BP in adolescent athletes is unclear. Hence, the purpose of this study was to examine the incidence of BP in young elite athletes in relation to gender and type of sport practiced. Methods Subjective BP was assessed in 321 elite adolescent athletes (m/f 57%/43%; 13.2 ± 1.4 years; 163.4 ± 11.4 cm; 52.6 ± 12.6 kg; 5.0 ± 2.6 training yrs; 7.6 ± 5.3 training h/week). Initially, all athletes were free of pain. The main outcome criterion was the incidence of back pain [%] analyzed in terms of pain development from the first measurement day (M1) to the second measurement day (M2) after 2.0 ± 1.0 year. Participants were classified into athletes who developed back pain (BPD) and athletes who did not develop back pain (nBPD). BP (acute or within the last 7 days) was assessed with a 5-step face scale (face 1–2 = no pain; face 3–5 = pain). BPD included all athletes who reported faces 1 and 2 at M1 and faces 3 to 5 at M2. nBPD were all athletes who reported face 1 or 2 at both M1 and M2. Data was analyzed descriptively. Additionally, a Chi2 test was used to analyze gender- and sport-specific differences (p = 0.05). Results Thirty-two athletes were categorized as BPD (10%). The gender difference was 5% (m/f: 12%/7%) but did not show statistical significance (p = 0.15). The incidence of BP ranged between 6 and 15% for the different sport categories. Game sports (15%) showed the highest, and explosive strength sports (6%) the lowest incidence. Anthropometrics or training characteristics did not significantly influence BPD (p = 0.14 gender to p = 0.90 sports; r2 = 0.0825). Conclusions BP incidence was lower in adolescent athletes compared to young non-athletes and even to the general adult population. Consequently, it can be concluded that high-performance sports do not lead to an additional increase in back pain incidence during early adolescence. Nevertheless, back pain prevention programs should be implemented into daily training routines for sport categories identified as showing high incidence rates. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 310 KW - Injury KW - Pain occurrence KW - Training volume KW - Young athletes Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-101874 ER - TY - CHAP A1 - Hain, Gerrit A1 - Müller, Juliane A1 - Müller, Steffen A1 - Reschke, Antje A1 - Mayer, Frank T1 - Reliability of an in-vivo 3-segmental kinematic trunk model in a one-handed lifting task T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2013 SN - 0195-9131 SN - 1530-0315 VL - 45 IS - 5 SP - 174 EP - 174 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Reschke, Antje A1 - Müller, Juliane A1 - Müller, Steffen A1 - Engel, Tilman A1 - Mayer, Frank T1 - Three-dimensional spine kinematics during perturbed treadmill walking - a pilot study T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2013 SN - 0195-9131 SN - 1530-0315 VL - 45 IS - 5 SP - 172 EP - 172 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Engel, Tilman A1 - Müller, Juliane A1 - Müller, Steffen A1 - Reschke, Antje A1 - Kopinski, Stephan A1 - Mayer, Frank T1 - Validity and reliability of a new customised split-belt treadmill provoking unexpected walking perturbations T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2013 SN - 0195-9131 SN - 1530-0315 VL - 45 IS - 5 SP - 462 EP - 462 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - CHAP A1 - Müller, Juliane A1 - Weber, Josefine A1 - Otto, Christoph A1 - Müller, Steffen A1 - Mayer, Frank T1 - Effects of six-month trunk stability exercises on low back pain prevalence in young athletes T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2012 SN - 0195-9131 VL - 44 SP - 601 EP - 601 PB - Lippincott Williams & Wilkins CY - Philadelphia ER -