Intra-session test-retest reliability of pelvic floor muscle electromyography during running

Introduction and hypothesis: The prevalence of female stress urinary incontinence is high, and young adults are also affected, including athletes, especially those involved in "high-impact” sports. To date there have been almost no studies testing pelvic floor muscle (PFM) activity during dynamic functional whole body movements. The aim of this study was the description and reliability test of PFM activity and time variables during running. Methods: A prospective cross-sectional study including ten healthy female subjects was designed with the focus on the intra-session test-retest reliability of PFM activity and time variables during running derived from electromyography (EMG) and accelerometry. Results: Thirteen variables were identified based on ten steps of each subject: Six EMG variables showed good reliability (ICC 0.906-0.942) and seven time variables did not show good reliability (ICC 0.113-0.731). Time variables (e.g. time difference between heel strike and maximal acceleration of vaginal accelerator) showed low reliability. However, relevant PFM EMG variables during running (e.g., pre-activation, minimal and maximal activity) could be identified and showed good reliability. Conclusion: Further adaptations regarding measurement methods should be tested to gain better control of the kinetics and kinematics of the EMG probe and accelerometers. To our knowledge this is the first study to test the reliability of PFM activity and time variables during dynamic functional whole body movements. More knowledge of PFM activity and time variables may help to provide a deeper insight into physical strain with high force impacts and important functional reflexive contraction patterns of PFM to maintain or to restore continenc

Stochastic resonance training at work reduces musculoskeletal pain in nurses

This randomized controlled trial (RCT) reports effects of a preventive intervention at worksite, namely stochastic resonance whole-body vibration (SR-WBV) training on musculoskeletal pain (MSP). SR-WBV is a form of wholebody vibration training with randomized low frequency vibration. The force-time behavior of the vibrations is not foreseeable and the body will be constantly challenged to adapt the muscle reactions. The experimental group (EG) performed an eight-week of SR-WBV. The control group (CG) received no intervention. The RCT was conducted in a large Swiss hospital. The 180 participants were between 18 and 63 years old (M = 43; SD = 11). The majority were female (88%) and were nurses (45%). MSP was measured daily in a diary. Participation possibilities and general health were assessed by self-report questionnaires before the RCT started. A longitudinal multilevel analysis showed a significant interaction of SR-WBV by time showed MSP to decline in the EG. Moreover, SWBV-training reduced pain to the largest extent in those with lowest participation possibilities and those who reported only moderate general health. Thus, SR-WBV was most effective in those reporting risk factors for musculoskeletal pain. SR-WBV may help to reduce the high prevalence of occupational musculoskeletal pain in hospital staff. Keywords: Worksite Intervention, Back Pain, Participation at Work, General Health

Electromyographic activity of back muscles during stochastic whole body vibration

OBJECTIVES: Stochastic resonance whole body vibrations (SR-WBV) may reduce and prevent musculoskeletal problems (MSP). The aim of this study was to evaluate how activities of the lumbar erector spinae (ES) and of the ascending and descending trapezius (TA, TD) change in upright standing position during SR-WBV. METHODS: Nineteen female subjects completed 12 series of 10 seconds of SR-WBV at six different frequencies (2, 4, 6, 8, 10, 12Hz) and two types of "noise"-applications. An assessment at rest had been executed beforehand. Muscle activities were measured with EMG and normalized to the maximum voluntary contraction (MVC%). For statistical testing a three-factorial analysis of variation (ANOVA) was applied. RESULTS: The maximum activity of the respective muscles was 14.5 MVC% for the ES, 4.6 MVC% for the TA (12Hz with "noise" both), and 7.4 MVC% for the TD (10Hz without "noise"). Furthermore, all muscles varied significantly at 6Hz and above (p⋜0.047) compared to the situation at rest. No significant differences were found at SR-WBV with or without "noise". CONCLUSIONS: In general, muscle activity during SR-WBV is reasonably low and comparable to core strength stability exercises, sensorimotor training and "abdominal hollowing" in water. SR-WBV may be a therapeutic option for the relief of MSP

Spatiotemporal gait parameters during dual task walking in need of care elderly and young adults: A cross-sectional study

Background: Up to now there have only been marginal data in the elderly in need of care regarding spatiotemporal gait parameters during single (ST) and dual tasking (DT). Aim: The aim of this study was to allocate data for gait speed, cadence and stride length cycle variability in the elderly in need of care and in young adults during ST and DT, to compare the two groups and to demonstrate the impact of ST and DT on gait parameters. Material and methods: This cross-sectional study investigated a group of 16 young healthy adults (mean age 23.0 ± 2.5 years) and a group of 16 elderly persons in need of care (mean age 85.5 ± 0.6 years). The RehaWatch® system was used to collect the spatiotemporal gait parameters cadence, speed and stride length. The participants completed four different measurements during normal walking and fast walking during ST and DT over a walking distance of 20m. The Wilcoxon rank sum test and Whitney-U test were used for statistical analysis. Results: Gait speed (ST and DT: p < 0.001), cadence (ST and DT: p < 0.001) and gait variability (ST: p = 0.007, DT: p = 0.003) were significantly reduced in the elderly in need of care group compared to the young group. The gait speed in the elderly in need of care group decreased from normal to fast walking (ST = − 2.8 %, DT = − 12.2 %) compared to the young group (ST = 31.5 %, DT = 25.2 %). Conclusion: The results of this study are comparable with the results of existing studies, which investigated falling and non-falling participants. Elderly people in need of care cannot increase the normal gait speed