Spine stabilization exercises, in which patients are taught to perform isolated contractions of the transverses abdominus (TrA) during ''abdominal hollowing'', are a popular physiotherapeutic treatment for low back pain (LBP). Successful performance is typically judged by the relative increase in TrA thickness compared with that of the internal (OI) and external (OE) oblique muscles, measured using ultrasound. The day-to-day measurement error (imprecision) associated with these indices of preferential activation has not been assessed but is important to know since it influences the interpretation of changes after treatment. On 2 separate days, 14 controls and 14 patients with chronic LBP (cLBP) performed abdominal hollowing exercises in hook-lying, while M-mode ultrasound images superimposed with tissue Doppler imaging (TDI) data were recorded from the abdominal muscles (N = 5 on each side). The fascial lines bordering the TrA, OI and OE were digitized, and muscle thicknesses were calculated. The betweenday error (intra-observer) was expressed as the standard error of measurement, SEM; SEM as a percentage of the mean gave the coefficient of variation (CV). There were no significant between-day differences for the mean values of resting or maximal thickness for any muscle, in either group (P [ 0.05). The median SEM and CV of all thickness variables was 0.71 mm and 10.9%, respectively for the controls and 0.80 mm or 11.3%, respectively for the cLBP patients. For the contraction ratios (muscle thickness contracted/ thickness at rest), the CVs were 3-11% (controls) and 5-12% (patients). The CVs were unacceptably high (30-50%, both groups) for the TrA preferential activation ratio (TrA proportion of the total lateral abdominal muscle thickness when contracted minus at rest). In both the controls and patients, the precision of measurement of absolute muscle thickness and relative change in thickness during abdominal hollowing was acceptable, and commensurate with that typical of biological measurements. The TrA preferential activation ratio is too imprecise to be of clinical use. Knowledge of the SEM for these indices is essential for interpreting the clinical relevance of any changes observed following physiotherapy.

Spine stabilisation exercises, in which patients are taught to preferentially activate the transversus abdominus (TrA) during ''abdominal hollowing'' (AH), are a popular treatment for chronic low back pain (cLBP). The present study investigated whether performance during AH differed between cLBP patients and controls to an extent that would render it useful diagnostic tool. 50 patients with cLBP (46.3 ± 12.5 years) and 50 healthy controls (43.6 ± 12.7 years) participated in this case-control study. They performed AH in hook-lying. Using M-mode ultrasound, thicknesses of TrA, and obliquus internus and externus were determined at rest and during 5 s AH (5 measures each body side). The TrA contraction-ratio (TrA-CR) (TrA contracted/rest) and the ability to sustain the contraction [standard deviation (SD) of TrA thickness during the stable phase of the hold] were investigated. There were no significant group differences for the absolute muscle thicknesses at rest or during AH, or for the SD of TrA thickness. There was a small but significant difference between the groups for TrA-CR: cLBP 1.35 ± 0.14, controls 1.44 ± 0.24 (p \ 0.05). However, Receiver Operator Characteristics (ROC) analysis revealed a poor and non-significant ability of TrA-CR to discriminate between cLBP patients and controls on an individual basis (ROC area under the curve, 0.60 [95% CI 0.495; 0.695], p = 0.08). In the patient group, TrA-CR showed a low but significant correlation with Roland Morris score (Spearman Rho = 0.328; p = 0.02). In conclusion, the difference in group mean values for TrA-CR was small and of uncertain clinical relevance. Moreover, TrA-CR showed a poor ability to discriminate between control and cLBP subjects on an individual basis. We conclude that the TrA-CR during abdominal hollowing does not distinguish well between patients with chronic low back pain and healthy controls.

ANOVA. 20Results. In both groups, feed-forward activity of the lateral abdominal muscles was 21 recorded during arm movements in all directions. The main effect of "group 22 membership" revealed no significant difference between the groups for the earliest 23 onset of abdominal muscle activity (p=0.398). However, a significant "group x body 24 side" interaction (p=0.015) was observed, and this was the result of earlier onsets 25 *Structured Abstract (300 words)Abdominal muscle feed-forward activity and back pain 2 in the cLBP group than controls for the abdominal muscles on the right (but not left) 1 body side. No relationship was found between the time of onset of the earliest 2 abdominal muscle activity and pain intensity, pain frequency, pain medication 3 usage or Roland Morris disability scores. 4 Conclusion.Patients with cLBP did not show a delayed onset of feedforward 5 activation of the lateral abdominal muscles during rapid arm movements. Earlier 6 activation was observed for one body side compared with the controls. However, 7 the clinical relevance of this finding remains obscure, especially since there was no 8 relationship between the onset of activation and any clinical parameters. 9Abdominal muscle feed-forward activity and back pain 1 Key Points 1 This study sought to compare the timing of activation of the lateral abdominal 2 muscles during rapid arm movements in patients with cLBP and pain-free 3 controls. 4 Both groups showed feed-forward activity of the lateral abdominal muscles 5 (i.e., onset of activity < 50 ms after activation of the deltoid muscle, the prime 6 mover for the movement). 7  The ANOVA revealed a statistically significant (p=0.015) "group x body side" 8 interaction, which was the result of earlier onsets in the cLBP group than 9 controls for the abdominal muscles on the right (but not left) body side 10  No relationship was found between the onset of the earliest abdominal muscle 11 activity and pain intensity, pain frequency, pain medication usage or Roland 12Morris disability scores. Abdominal muscle feed-forward activity and back pain 1 Mini Abstract 1Using non-invasive tissue Doppler imaging, the timing of activation of the lateral 2 abdominal muscles during rapid arm movements was compared in patients with 3 chronic low back pain and controls. Both groups showed feed-forward activation. 4For left-arm movements, the patients showed earlier activation than the controls. 5No relationship was found between the onset of activation and pain or disability, 6questioning the clinical relevance of the findings. 7 *Mini Abstract (50 words)

Objectives: Despite established principles of perinatal palliative care (PnPC), implementation into practice has shown inconsistencies. The aim of this study was to assess PnPC services, examine healthcare professionals (HCPs) awareness and availability of PnPC guidelines, and describe HCPs satisfaction with PC and guidelines.Material and Methods: A nationwide survey was conducted in Swiss tertiary NICUs between April-November 2019. Data were examined by descriptive statistics and linear regression models.Results: Overall response rate was 54% (65% physicians; 49% nurses; 72% psychosocial staff). Half of professionals (50%) received education in PC during their medical/nursing school, whereas 36% indicated they obtained further training in PnPC at their center. PnPC guidelines were available in 4/9 centers, with 68% HCPs being aware of the guideline. Professionals who had access to a PnPC team (P = 0.001) or were part of the nursing (P = 0.003) or psychosocial staff (P = 0.001) were more likely aware of having a guideline. Twenty-eight percent indicated being satisfied with PC in their center. Professionals with guideline awareness (P = 0.025), further training (P = 0.001), and access to a PnPC team (P &lt; 0.001) were more likely to be satisfied, whereas HCPs with a nursing background (P &lt; 0.001) were more likely to be dissatisfied. A majority expressed the need for a PnPC guideline (80%) and further PC training (94%).Conclusion: This study reveals lacking PnPC guidelines and divergences regarding onsite opportunities for continued training across Swiss level III NICUs. Extending PnPC guidelines and training services to all centers can help bridge the barriers created by fragmented practice.