TY - GEN A1 - Martinez-Valdes, Eduardo A1 - Negro, Francesco A1 - Laine, Christopher M. A1 - Falla, Deborah L. A1 - Mayer, Frank A1 - Farina, Dario T1 - Identifying motor units in longitudinal studies with high-density surface electromyography T2 - Converging clinical and engineering research on neurorehabilitation II N2 - We investigated the possibility to identify motor units (MUs) with high-density surface electromyography (HDEMG) over experimental sessions in different days. 10 subjects performed submaximal knee extensions across three sessions in three days separated by one week, while EMG was recorded from the vastus medialis muscle with high-density electrode grids. The shapes of the MU action potentials (MUAPs) over multiple channels extracted from HDEMG decomposition were matched across sessions by cross-correlation. Forty and twenty percent of the MUs decomposed could be tracked across two and three sessions, respectively (average cross correlation 0.85 +/- 0.04). The estimated properties of the matched motor units were similar across the sessions. For example, mean discharge rate and recruitment thresholds were measured with an intra-class correlation coefficient (ICCs) > 0.80. These results strongly suggest that the same MUs were indeed identified across sessions. This possibility will allow monitoring changes in MU properties following interventions or during the progression of neuromuscular disorders. Y1 - 2016 SN - 978-3-319-46669-9 SN - 978-3-319-46668-2 U6 - https://doi.org/10.1007/978-3-319-46669-9_27 SN - 2195-3562 VL - 15 SP - 147 EP - 151 PB - Springer CY - Cham ER - TY - GEN A1 - Wippert, Pia-Maria A1 - Puschmann, Anne-Katrin A1 - Schiltenwolf, Marcus A1 - Wiebking, Christine A1 - Mayer, Frank T1 - BACK PAIN: THE STUDY OF MECHANISMS AND THE TRANSLATION IN INTERVENTIONS WITHIN THE MISPEX NETWORK T2 - Psychosomatic medicine Y1 - 2016 SN - 0033-3174 SN - 1534-7796 VL - 78 SP - A91 EP - A91 PB - Elsevier CY - Philadelphia ER - TY - GEN A1 - De Witt Huberts, Jessie A1 - Niederer, Daniel A1 - Wippert, Pia-Maria A1 - Mayer, Frank T1 - The effects of a new practical and synergetic multimodal treatment for chronic back pain on pain-related cognitions and wellbeing T2 - Psychosomatic medicine Y1 - 2017 SN - 0033-3174 SN - 1534-7796 VL - 79 IS - 4 SP - A22 EP - A23 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - GEN A1 - Puschmann, Anne-Kathrin A1 - Beck, Heidrun A1 - Schiltenwolf, Marcus A1 - Wippert, Pia-Maria A1 - Mayer, Frank T1 - Distress in a longitudinal study of a population with nonspecific low back pain T2 - Psychosomatic medicine Y1 - 2017 SN - 0033-3174 SN - 1534-7796 VL - 79 SP - A20 EP - A21 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - GEN A1 - Chaparro, Camilo G. A. Perez A1 - Zech, Philipp A. A1 - Heinzel, Stephan A1 - Mayer, Frank A1 - Wolfarth, Bernd A1 - Rapp, Michael Armin A1 - Heissel, Andreas T1 - Effects Of Aerobic & Resistance Training On Cardiorespiratory Fitness In People Living with HIV. A Meta-analysis T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2017 U6 - https://doi.org/10.1249/01.mss.0000519265.28705.86 SN - 0195-9131 SN - 1530-0315 VL - 49 SP - 842 EP - 842 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - GEN A1 - Molnar, Marco A1 - Kok, Manor A1 - Engel, Tilman A1 - Kaplic, Hannes A1 - Mayer, Frank A1 - Seel, Thomas T1 - A method for lower back motion assessment using wearable 6D inertial sensors T2 - 21st International Conference on Information Fusion (FUSION) N2 - Low back pain (LBP) is a leading cause of activity limitation. Objective assessment of the spinal motion plays a key role in diagnosis and treatment of LBP. We propose a method that facilitates clinical assessment of lower back motions by means of a wireless inertial sensor network. The sensor units are attached to the right and left side of the lumbar region, the pelvis and the thighs, respectively. Since magnetometers are known to be unreliable in indoor environments, we use only 3D accelerometer and 3D gyroscope readings. Compensation of integration drift in the horizontal plane is achieved by estimating the gyroscope biases from automatically detected initial rest phases. For the estimation of sensor orientations, both a smoothing algorithm and a filtering algorithm are presented. From these orientations, we determine three-dimensional joint angles between the thighs and the pelvis and between the pelvis and the lumbar region. We compare the orientations and joint angles to measurements of an optical motion tracking system that tracks each skin-mounted sensor by means of reflective markers. Eight subjects perform a neutral initial pose, then flexion/extension, lateral flexion, and rotation of the trunk. The root mean square deviation between inertial and optical angles is about one degree for angles in the frontal and sagittal plane and about two degrees for angles in the transverse plane (both values averaged over all trials). We choose five features that characterize the initial pose and the three motions. Interindividual differences of all features are found to be clearly larger than the observed measurement deviations. These results indicate that the proposed inertial sensor-based method is a promising tool for lower back motion assessment. KW - Inertial measurement units KW - joint angle estimation KW - human motion analysis KW - low back pain KW - back motion assessment KW - avoid magnetometers KW - validation against optical motion capture KW - drift correction Y1 - 2018 SN - 978-0-9964-5276-2 SP - 799 EP - 806 PB - IEEE CY - New York ER - TY - GEN A1 - Khajooei, Mina A1 - Lin, Chiao-I A1 - Steffan, Müller A1 - Mayer, Frank T1 - Effect of Instability in Legpress Testing on Strength & Muscle Activity in Functional Ankle Instability T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine Y1 - 2018 U6 - https://doi.org/:10.1249/01.mss.0000537073.01736.db SN - 0195-9131 SN - 1530-0315 VL - 50 IS - 5S SP - 602 EP - 602 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - GEN A1 - Pérez Chaparro, Camilo Germán Alberto A1 - Mayer, Frank A1 - Beckendorf, Claudia T1 - Cardiovascular drift response over two different constant-load exercises in healthy non-athletes BT - case study T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine N2 - Cardiovascular drift (CV-d) is a steady increase in heart rate (HR) over time while performing constant load moderate intensity exercise (CME) > 20 min. CV-d presents problems for the prescription of exercise intensity by means of HR, because the work rate (WR) during exercise must be adjusted to maintain target HR, thus disturbing the intended effect of the exercise intervention. It has been shown that the increase in HR during CME is due to changes in WR and not to CV-d. Y1 - 2019 U6 - https://doi.org/10.1249/01.mss.0000561495.15163.50 SN - 0195-9131 SN - 1530-0315 VL - 51 IS - 6 SP - 329 EP - 329 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - GEN A1 - Schraplau, Anne A1 - Sonnenburg, Dominik A1 - Wochatz, Monique A1 - Engel, Tilman A1 - Schomöller, Anne A1 - Risch, Lucie A1 - Kaplick, Hannes A1 - Mayer, Frank T1 - Characterization of muscle damage and inflammation following repeated maximal eccentric loading of the trunk T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine N2 - Eccentric exercises (ECC) induce reversible muscle damage, delayed-onset muscle soreness and an inflammatory reaction that is often followed by a systemic anti-inflammatory response. Thus, ECC might be beneficial for treatment of metabolic disorders which are frequently accompanied by a low-grade systemic inflammation. However, extent and time course of a systemic immune response after repeated ECC bouts are poorly characterized. PURPOSE: To analyze the (anti-)inflammatory response after repeated ECC loading of the trunk. METHODS: Ten healthy participants (33 ± 6 y; 173 ± 14 cm; 74 ± 16 kg) performed three isokinetic strength measurements of the trunk (concentric (CON), ECC1, ECC2, each 2 wks apart; flexion/extension, velocity 60°/s, 120s MVC). Pre- and 4, 24, 48, 72, 168h post-exercise, muscle soreness (numeric rating scale, NRS) was assessed and blood samples were taken and analyzed [Creatine kinase (CK), C-reactive protein (CRP), Interleukin-6 (IL-6), IL-10, Tumor necrosis factor-α (TNF-α)]. Statistics were done by Friedman‘s test with Dunn‘s post hoc test (α=.05). RESULTS: Mean peak torque was higher during ECC1 (319 ± 142 Nm) than during CON (268 ± 108 Nm; p<.05) and not different between ECC1 and ECC2 (297 ± 126 Nm; p>.05). Markers of muscle damage (peaks post-ECC1: NRS 48h, 4.4±2.9; CK 72h, 14407 ± 19991 U/l) were higher after ECC1 than after CON and ECC2 (p<.05). The responses over 72h (stated as Area under the Curve, AUC) were abolished after ECC2 compared to ECC1 (p<.05) indicating the presence of the repeated bout effect. CRP levels were not changed. IL-6 levels increased 2-fold post-ECC1 (pre: 0.5 ± 0.4 vs. 72h: 1.0 ± 0.8 pg/ml). The IL-6 response was enhanced after ECC1 (AUC 61 ± 37 pg/ml*72h) compared to CON (AUC 33 ± 31 pg/ml*72h; p<.05). After ECC2, the IL-6 response (AUC 43 ± 25 pg/ml*72h) remained lower than post-ECC1, but the difference was not statistically significant. Serum levels of TNF-α and of the anti-inflammatory cytokine IL-10 were below detection limits. Overall, markers of muscle damage and immune response showed high inter-individual variability. CONCLUSION: Despite maximal ECC loading of a large muscle group, no anti-inflammatory and just weak inflammatory responses were detected in healthy adults. Whether ECC elicits a different reaction in inflammatory clinical conditions is unclear. Y1 - 2020 U6 - https://doi.org/10.1249/01.mss.0000679532.65880.af SN - 0195-9131 SN - 1530-0315 VL - 52 IS - 7S SP - 497 EP - 497 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - GEN A1 - Schomöller, Anne A1 - Risch, Lucie A1 - Kaplick, Hannes A1 - Schraplau, Anne A1 - Wochatz, Monique A1 - Engel, Tilman A1 - Sonnenburg, Dominik A1 - Mayer, Frank T1 - Changes in paraspinal muscle T2 times and creatine kinase after a bout of eccentric exercise T2 - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine N2 - Eccentric (ECC) exercises might cause muscle damage, characterized by delayed-onset muscle soreness, elevated creatine kinase (CK) levels and local muscle oedema, shown by elevated T2 times in magnet resonance imaging (MRI) scans. Previous research suggests a high inter-individual difference regarding these systemic and local responses to eccentric workload. PURPOSE: To analyze ECC exercise-induced muscle damage in lumbar paraspinal muscles assessed via MRI. METHODS: Ten participants (3f/7m; 33±6y; 174±8cm; 71±12kg) were included in the study. Quantitative paraspinal muscle constitution of M. erector spinae and M. multifidius were assessed in supine position before and 72h after an intense eccentric trunk exercise bout in a mobile 1.5 tesla MRI device. MRI scans were recorded on spinal level L3 (T2-weighted TSE echo sequences, 11 slices, 2mm slice thickness, 3mm gap, echo times: 20, 40, 60, 80, 100ms, TR time: 2500ms). Muscle T2 times were calculated for manually traced regions of interest of the respective muscles with an imaging software. The exercise protocol was performed in an isokinetic device and consisted of 120sec alternating ECC trunk flexion-extension with maximal effort. Venous blood samples were taken before and 72h after the ECC exercise. Descriptive statistics (mean±SD) and t-testing for pre-post ECC exercises were performed. RESULTS: T2 times increased from pre- to post-ECC MRI measurements from 55±3ms to 79±28ms in M. erector spinae and from 62±5ms to 78±24ms in M. multifidius (p<0.001). CK increased from 126±97 U/L to 1447±20579 U/L. High SDs of T2 time and CK in post-ECC measures could be due to inter-individual reactions to ECC exercises. 3 participants showed high local and systemic reactions (HR) with T2 time increases of 120±24% (M. erector spinae) and 73±50% (M. multifidius). In comparison, the remaining 7 participants showed increases of 11±12% (M. erector spinae) and 7±9% (M. multifidius) in T2 time. Mean CK increased 9.5-fold in the 3 HR subjects compared with the remaining 7 subjects. CONCLUSIONS: The 120sec maximal ECC trunk flexion-extension protocol induced high amounts of muscle damage in 3 participants. Moderate to low responses were found in the remaining 7 subjects, assuming that inter-individual predictors play a role regarding physiological responses to ECC workload. Y1 - 2020 U6 - https://doi.org/10.1249/01.mss.0000685648.68626.f1 SN - 0195-9131 SN - 1530-0315 SN - 0025-7990 VL - 52 IS - 17 SP - 929 EP - 929 PB - Lippincott Williams & Wilkins CY - Philadelphia ER -