Background: Development of more effective interventions for nonspecific chronic low back pain (LBP), requires a robust theoretical framework regarding mechanisms underlying the persistence of LBP. Altered movement patterns, possibly driven by pain-related cognitions, are assumed to drive pain persistence, but cogent evidence is missing. Aim: To assess variability and stability of lumbar movement patterns, during repetitive seated reaching, in people with and without LBP, and to investigate whether these movement characteristics are associated with painrelated cognitions. Methods: 60 participants were recruited, matched by age and sex (30 back-healthy and 30 with LBP). Mean age was 32.1 years (SD13.4). Mean Oswestry Disability Index-score in LBP-group was 15.7 (SD12.7). Pain-related cognitions were assessed by the ‘Pain Catastrophizing Scale’ (PCS), ‘Pain Anxiety Symptoms Scale’ (PASS) and the task-specific ‘Expected Back Strain’ scale(EBS). Participants performed a seated repetitive reaching movement (45 times), at self-selected speed. Lumbar movement patterns were assessed by an optical motion capture system recording positions of cluster markers, located on the spinous processes of S1 and T8. Movement patterns were characterized by the spatial variability (meanSD) of the lumbar Euler angles: flexion-extension, lateralbending, axial-rotation, temporal variability (CyclSD) and local dynamic stability (LDE). Differences in movement patterns, between people with and without LBP and with high and low levels of pain-related cognitions, were assessed with factorial MANOVA. Results: We found no main effect of LBP on variability and stability, but there was a significant interaction effect of group and EBS. In the LBP-group, participants with high levels of EBS, showed increased MeanSDlateral-bending (p = 0.004, η2 = 0.14), indicating a large effect. MeanSDaxial-rotation approached significance (p = 0.06). Significance: In people with LBP, spatial variability was predicted by the task-specific EBS, but not by the general measures of pain-related cognitions. These results suggest that a high level of EBS is a driver of increased spatial variability, in participants with LBP.
Background Anxiety and challenging behaviour (CB) often occur simultaneously in people with intellectual disabilities (ID). Understanding the associations between anxiety and CB may contribute to more accurate diagnoses and management of both anxiety and CB in this population. Aims To examine the relationship between anxiety and CB. Methods A literature review covering the period from January 2000 to January 2012. Results Seven studies about the relationship between psychiatric disorders, including anxiety, and CB were identified. These studies confirm the relationship between anxiety and CB in people with ID, although the precise nature of this relationship remains unclear. Conclusions The study points toward the existence of a moderate association between anxiety and CB. Further research is needed to clarify the complex nature of the association between anxiety and CB.
Virtual training systems provide highly realistic training environments for police. This study assesses whether a pain stimulus can enhance the training responses and sense of the presence of these systems. Police officers (n = 219) were trained either with or without a pain stimulus in a 2D simulator (VirTra V-300) and a 3D virtual reality (VR) system. Two (training simulator) × 2 (pain stimulus) ANOVAs revealed a significant interaction effect for perceived stress (p =.010, ηp2 =.039). Post-hoc pairwise comparisons showed that VR provokes significantly higher levels of perceived stress compared to VirTra when no pain stimulus is used (p =.009). With a pain stimulus, VirTra training provokes significantly higher levels of perceived stress compared to VirTra training without a pain stimulus (p <.001). Sense of presence was unaffected by the pain stimulus in both training systems. Our results indicate that VR training appears sufficiently realistic without adding a pain stimulus. Practitioner summary: Virtual police training benefits from highly realistic training environments. This study found that adding a pain stimulus heightened perceived stress in a 2D simulator, whereas it influenced neither training responses nor sense of presence in a VR system. VR training appears sufficiently realistic without adding a pain stimulus.
