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 20 m. 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.

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.

[The relevance of core muscles in ice hockey players: a feasibility study]. / Die Bedeutung der Rumpfmuskulatur bei Eishockeyspielern: eine Machbarkeitsstudie.

BACKGROUND: Good core strength is seen as a condition for high performance in sports. In general, especially maximum voluntary contraction (MVC) and strength endurance (SE) measurements of the core muscles are used. In addition, a few studies can be found that examine the core muscles in terms of MVC, rate of force development (RFD) and SE. Primary aims of this feasibility study were to investigate the feasibility regarding recruiting process, compliance and safety of the testing conditions and raise the force capabilities MVC, RFD and SE of the core muscles in amateur ice hockey players. Secondarily, tendencies of correlations between muscle activity and either shot speed and sprint time shall be examined. SUBJECTS/METHODS: In this feasibility study the recruitment process has been approved by 29 ice hockey players, their adherence to the study measurements of trunk muscles, and safety of the measurements was evaluated. To determine the MVC, RFD and SE for the ventral, lateral and dorsal core muscles a dynamic force measurement was performed. To determine the correlation between core muscles and shot speed and 40-m sprint, respectively, the rank correlation coefficient (rho) from Spearman was used. RESULTS: The recruited number of eight field players and one goal-keeper was not very high. The compliance with 100 % was excellent. The players reported no adverse symptoms or injuries after the measurements. The results show median values for the ventral core muscles for MVC with 46.5 kg for RFD with 2.23 m/s2 and 96 s for the SE. For lateral core muscle median values of the lateral core muscles for MVC with 71.10 kg, RFD with 2.59 m/s2 and for SE over 66 s were determined. The dorsal core muscles shows values for MVC 69.7 kg, for RFD 3.39 m/s2 and for SE of 75 s. High correlations between MVC of the ventral core muscles (rho = -0.721, p = 0.021), and between the SE of the ventral core muscles (rho = 0.787, p = 0.012), and the shot velocity rate were determined. Another high correlation between SE of the ventral core muscles and sprint over 40 m (rho = 0.717, p = 0.030) could be demonstrated. CONCLUSION: This feasibility study has shown that the implementation of the selected design is adapted for future studies. Further studies are needed to better understand the relationship between the velocity rate and the MVC, and the SE respectively, as well as between the sprint and the SE.

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 continence.

[Acute effects of fast dynamic stretching on rate of force development in ice hockey players: a pilot study]. / Akute Effekte des schnellen dynamischen Dehnens auf die Schnellkraft von Eishockeyspielern: eine Pilotstudie.

BACKGROUND: Fast dynamic stretching has a positive effect on rate of force development in ice hockey players. The aim of this pilot study was to evaluate the influence of fast dynamic stretching (FDS) of the gluteus maximus muscle on rate of force development. SUBJECTS/METHODS: This study included 12 healthy ice hockey players. The intervention was based on a fast dynamic stretching of the gluteus maximus muscle. For quantification, measurements were performed before and after the intervention. The rate of force development was determined by using the drop jump (DJ) for ground contact time and jump height, and sprint time was measured on ice over 20 meters. RESULTS: The intervention showed significant extension of the ground reaction time. The jump height and the sprint time showed no significant differences after FDS intervention. CONCLUSION: The data in this present randomised controlled pilot study showed that FDS interventions on the gluteus maximus muscle have no influence on rate of force development. For future studies, it is recommended that the study protocol should be modified with regard to determining the stretched muscle groups. Furthermore, the FDS intervention on the gluteus maximus muscle showed no positive influence on DJ and sprint.

Continuous versus intermittent stochastic resonance whole body vibration and its effect on pelvic floor muscle activity.

AIMS: To determine the optimal stochastic whole body vibration (SR-WBV) load modality regarding pelvic floor muscle (PFM) activity in order to complete the SR-WBV training methodology for future PFM training with SR-WBV. METHODS: The continuous and the intermittent SR-WBV modalities were tested by means of electromyography in two independent groups (27 women 8 weeks to 1-year postpartum and 23 women nulliparae or >1-year postpartum) with self-reported stress urinary incontinence. The change in the PFM activity within a single set and over three sets were calculated for both SR-WBV modalities together (time effect) and for both SR-WBV modalities separately (modality-time interaction). RESULTS: There was no statistically significant or clinically relevant change in PFM activity over time or PFM fatigue in either SR-WBV modality within one or three sets and no difference between the modalities or the groups. CONCLUSIONS: The lack of change in PFM activity could be due to a no more than moderate to submaximal PFM activity during SR-WBV, the maintenance of reflexive PFM activity despite PFM fatigue or a compensation of slow red PFM fiber fatigue by an increase of innervation frequency and motor unit recruitment of the fast white fibers. As there is no SR-WBV modality dependent difference regarding PFM activity, the continuous modality is recommended in clinical practice as it is easier to apply and less time consuming.

Inter- and intra-observer agreement of Prechtl's method on the qualitative assessment of general movements in preterm, term and young infants.

BACKGROUND: Prechtl's method on the qualitative assessment of general movements (GMs) has been shown to be a good predictor of neurological outcome. There is substantial evidence that this method has good inter- and intra-observer agreement. AIMS: We wanted to find out whether this high agreement is reproducible in the clinical setting. STUDY DESIGN: Reliability study (inter- and intra-observer agreement). SUBJECTS: Twenty video-sequences of children at the age of preterm and writhing movements (31-41 weeks postmenstrual age) and 10 video-sequences of children at the fidgety movements age (49-54 weeks postmenstrual age) were rated by five physiotherapists. OUTCOME MEASURES: Intra- and inter-observer agreements were analyzed with percentage agreement and with nominal kappa statistic with bootstrapped bias corrected 95% confidence intervals. RESULTS: We found fair to substantial inter-observer reliability for the six response categories (time-point 1(t1): median kappa 0.44, range 0.27 to 0.59, time-point 2 (t2): median kappa 0.55, range 0.41 to 0.77) and fair to almost perfect for the normal/abnormal ratings (t1: median kappa 0.53, range 0.29 to 0.61, t2: median kappa 0.63, range 0.29 to 0.85). There was statistically significant improvement from t1 to t2 for the six response categories. The intra-observer reliability for the 9-week interval was moderate to almost perfect (median kappa 0.68, range 0.41 to 0.86). CONCLUSIONS: We were not able to exactly reproduce the generally very good results. In our clinical setting now videos are evaluated by at least two trained therapists and the results are discussed, if necessary, to reach a consensus.