TY - JOUR A1 - Stillmark, Hans-Christian ED - Langner, Paul Martin ED - Mirecka, Agata T1 - Perturbation als Analysemethode dramatischer Texte BT - Dramaturgien der "Störung" bei Bertolt Brecht und Heiner Müller JF - Tendenzen der zeitgenössischen Dramatik N2 - Perturbation als Analysemethode für dramatische Texte wird hier am Beispiel von Brecht und Müller ausprobiert. KW - Perturbation KW - Dramatik KW - Brecht KW - Heiner Müller Y1 - 2015 SN - 978-3-631-65597-9 SP - 11 EP - 29 PB - Lang-Ed. CY - Frankfurt, M. ER - TY - JOUR A1 - Müller, Juliane A1 - Stoll, Josefine A1 - Mueller, Steffen A1 - Mayer, Frank T1 - Dose-response relationship of core-specific sensorimotor interventions in healthy, well-trained participants BT - study protocol for a (MiSpEx) randomized controlled trial JF - Trials N2 - Background: Core-specific sensorimotor exercises are proven to enhance neuromuscular activity of the trunk, improve athletic performance and prevent back pain. However, the dose-response relationship and, therefore, the dose required to improve trunk function is still under debate. The purpose of the present trial will be to compare four different intervention strategies of sensorimotor exercises that will result in improved trunk function. Discussion: The results of the study will be clinically relevant, not only for researchers but also for (sports) therapists, physicians, coaches, athletes and the general population who have the aim of improving trunk function. KW - Sensorimotor training KW - Perturbation KW - Exercise KW - MiSpEx Y1 - 2018 U6 - https://doi.org/10.1186/s13063-018-2799-9 SN - 1745-6215 VL - 19 PB - BMC CY - London ER - TY - JOUR A1 - Mueller, Juliane A1 - Stoll, Josefine A1 - Mueller, Steffen A1 - Mayer, Frank T1 - Dose-response relationship of core-specific sensorimotor interventions in healthy, welltrained participants BT - study protocol for a (MiSpEx) randomized controlled trial JF - Trials N2 - Background: Core-specific sensorimotor exercises are proven to enhance neuromuscular activity of the trunk, improve athletic performance and prevent back pain. However, the dose-response relationship and, therefore, the dose required to improve trunk function is still under debate. The purpose of the present trial will be to compare four different intervention strategies of sensorimotor exercises that will result in improved trunk function. Methods/design: A single-blind, four-armed, randomized controlled trial with a 3-week (home-based) intervention phase and two measurement days pre and post intervention (M1/M2) is designed. Experimental procedures on both measurement days will include evaluation of maximum isokinetic and isometric trunk strength (extension/flexion, rotation) including perturbations, as well as neuromuscular trunk activity while performing strength testing. The primary outcome is trunk strength (peak torque). Neuromuscular activity (amplitude, latencies as a response to perturbation) serves as secondary outcome. The control group will perform a standardized exercise program of four sensorimotor exercises (three sets of 10 repetitions) in each of six training sessions (30 min duration) over 3 weeks. The intervention groups’ programs differ in the number of exercises, sets per exercise and, therefore, overall training amount (group I: six sessions, three exercises, two sets; group II: six sessions, two exercises, two sets; group III: six sessions, one exercise, three sets). The intervention programs of groups I, II and III include additional perturbations for all exercises to increase both the difficulty and the efficacy of the exercises performed. Statistical analysis will be performed after examining the underlying assumptions for parametric and non-parametric testing. Discussion: The results of the study will be clinically relevant, not only for researchers but also for (sports) therapists, physicians, coaches, athletes and the general population who have the aim of improving trunk function. KW - Sensorimotor training KW - Perturbation KW - Exercise KW - MiSpEx Y1 - 2018 U6 - https://doi.org/10.1186/s13063-018-2799-9 SN - 1745-6215 VL - 19 IS - 424 PB - BioMed Central CY - London ER - TY - JOUR A1 - Mueller, Juliane A1 - Martinez-Valdes, Eduardo Andrés A1 - Stoll, Josefine A1 - Mueller, Steffen A1 - Engel, Tilman A1 - Mayer, Frank T1 - Differences in neuromuscular activity of ankle stabilizing muscles during postural disturbances BT - a gender-specific analysis JF - Gait & posture N2 - The purpose was to examine gender differences in ankle stabilizing muscle activation during postural disturbances. Seventeen participants (9 females: 27 +/- 2yrs., 1.69 +/- 0.1 m, 63 +/- 7 kg; 8 males: 29 +/- 2yrs., 1.81 +/- 0.1 m; 83 +/- 7 kg) were included in the study. After familiarization on a split-belt-treadmill, participants walked (1 m/s) while 15 right-sided perturbations were randomly applied 200 ms after initial heel contact. Muscle activity of M. tibialis anterior (TA), peroneus longus (PL) and gastrocnemius medialis (GM) was recorded during unperturbed and perturbed walking. The root mean square (RMS; [%]) was analyzed within 200 ms after perturbation. Co-activation was quantified as ratio of antagonist (GM)/agonist (TA) EMG-RMS during unperturbed and perturbed walking. Time to onset was calculated (ms). Data were analyzed descriptively (mean +/- SD) followed by three-way-ANOVA (gender/condition/muscle; alpha= 0.05). Perturbed walking elicited higher EMG activity compared to normal walking for TA and PL in both genders (p < 0.000). RMS amplitude gender comparisons revealed an interaction between gender and condition (F = 4.6, p = 0.049) and, a triple interaction among gender, condition and muscle (F = 4.7, p = 0.02). Women presented significantly higher EMG-RMS [%] PL amplitude than men during perturbed walking (mean difference = 209.6%, 95% confidence interval = -367.0 to -52.2%, p < 0.000). Co-activation showed significant lower values for perturbed compared to normal walking (p < 0.000), without significant gender differences for both walking conditions. GM activated significantly earlier than TA and PL (p < 0.01) without significant differences between the muscle activation onsets of men and women (p = 0.7). The results reflect that activation strategies of the ankle encompassing muscles differ between genders. In provoked stumbling, higher PL EMG activity in women compared to men is present. Future studies should aim to elucidate if this specific behavior has any relationship with ankle injury occurrence between genders. KW - Lower extremity KW - EMG KW - Perturbation KW - Split-belt treadmill KW - Ankle Y1 - 2018 U6 - https://doi.org/10.1016/j.gaitpost.2018.01.023 SN - 0966-6362 SN - 1879-2219 VL - 61 SP - 226 EP - 231 PB - Elsevier CY - Clare ER - TY - JOUR A1 - Engel, Tilman A1 - Mueller, Juliane A1 - Kopinski, Stephan A1 - Reschke, Antje A1 - Mueller, Steffen A1 - Mayer, Frank T1 - Unexpected walking perturbations: Reliability and validity of a new treadmill protocol to provoke muscular reflex activities at lower extremities and the trunk JF - Journal of biomechanics N2 - Instrumented treadmills offer the potential to generate standardized walking perturbations, which are particularly rapid and powerful. However, technical requirements to release adequate perturbations regarding timing, duration and amplitude are demanding. This study investigated the test-retest reliability and validity of a new treadmill perturbation protocol releasing rapid and unexpected belt perturbations to provoke muscular reflex responses at lower extremities and the trunk. Fourteen healthy participants underwent two identical treadmill walking protocols, consisting of 10 superimposed one-sided belt perturbations (100 ms duration; 2 m/s amplitude), triggered by a plantar pressure insole 200 ms after heel contact. Delay, duration and amplitude of applied perturbations were recorded by 3D-motion capture. Muscular reflex responses (within 200 ms) were measured at lower extremities and the trunk (10-lead EMG). Data was analyzed descriptively (mean +/- SD). Reliability was analyzed using test-retest variability (TRV%) and limits of agreement (LoA, bias +/- 1.96*SD). Perturbation delay was 202 14 ms, duration was 102 +/- 4 ms and amplitude was 2.1 +/- 0.01 m/s. TRV for perturbation delay, duration and amplitude ranged from 5.0% to 5.7%. LoA reached 3 +/- 36 ms for delay, 2 +/- 13 ms for duration and 0.0 +/- 0.3 m/s for amplitude. EMG amplitudes following perturbations ranged between 106 +/- 97% and 909 +/- 979% of unperturbed gait and EMG latencies between 82 +/- 14 ms and 106 +/- 16 ms. Minor differences between preset and observed perturbation characteristics and results of test-retest analysis prove a high validity with excellent reliability of the setup. Therefore, the protocol tested can be recommended to provoke muscular reflex responses at lower extremities and the trunk in perturbed walking. (C) 2017 Elsevier Ltd. All rights reserved. KW - Perturbation KW - Stumbling KW - Gait KW - Treadmill KW - Reliability KW - MiSpEx Y1 - 2017 U6 - https://doi.org/10.1016/j.jbiomech.2017.02.026 SN - 0021-9290 SN - 1873-2380 VL - 55 SP - 152 EP - 155 PB - Elsevier CY - Oxford ER -