Effect of a Posture-Cueing Shirt on Sitting Posture During a Functional Task in Healthy Participants: A Randomized Cross-Over Study.

OBJECTIVES: The purpose of this study was to investigate the effect of a posture-cueing shirt on sitting posture during a functional task. METHODS: Thirty healthy male participants were seated at a standardized workstation while completing 3 laptop writing tasks of 15-minute duration wearing either a posture-cueing shirt, a compression shirt, or no shirt. Posture was assessed based on photos taken at minutes 1 and 15 into the writing task from which the head and shoulder angles were measured and extracted for analysis. After each task, participants rated any potential pain they felt during the task on an 11-point numeric rating scale (NRS). RESULTS: The results showed that none of the shirts significantly affected the head or shoulder angles at any time point. Participants reported lower pain levels after using the posture-cueing shirt (NRS 0 [0-1]) compared with no shirt (NRS 1 [0-2]; P = .012). No significant difference in pain levels was observed between shirts. CONCLUSION: Although posture did not change in any conditions for these healthy male participants, the posture-cueing shirt resulted in a lower pain intensity compared with no shirt but not with a compression shirt. Although a significant difference was found for pain intensity favoring the posture-cueing shirt, this difference was negligible, and thus its value to reduce pain or improve posture in healthy participants remains in question.

Longitudinal Changes and Associations Between Quantitative Sensory Testing and Psychological Factors in Whiplash-Associated Disorders: A Systematic Review and Meta-Analyses-Based Data Synthesis.

Whiplash-associated disorders (WAD) represent a multifactorial condition often accompanied by altered nociceptive processing and psychological factors. This systematic review on acute and chronic WAD aimed to investigate the relationship between quantitative sensory testing (QST) and psychological factors and quantify whether their trajectories over time follow a similar pattern to disability levels. Eight databases were searched until October 2022. When 2 prospective studies examined the same QST or psychological variable, data synthesis was performed with random-effects meta-analysis by pooling within-group standardized mean differences from baseline to 3-, 6-, and 12-month follow-ups. From 5,754 studies, 49 comprising 3,825 WAD participants were eligible for the review and 14 for the data synthesis. Altered nociceptive processing in acute and chronic WAD, alongside worse scores on psychological factors, were identified. However, correlations between QST and psychological factors were heterogeneous and inconsistent. Furthermore, disability levels, some QST measures, and psychological factors followed general positive improvement over time, although there were differences in magnitude and temporal changes. These results may indicate that altered psychological factors and increased local pain sensitivity could play an important role in both acute and chronic WAD, although this does not exclude the potential influence of factors not explored in this review. PERSPECTIVE: Acute WAD show improvements in levels of disability and psychological factors before significant improvements in nociceptive processing are evident. Facilitated nociceptive processing might not be as important as psychological factors in chronic WAD-related disability, which indicates that chronic and acute WAD should not be considered the same entity although there are similarities. Nonetheless, pressure pain thresholds in the neck might be the most appropriate measure to monitor WAD progression.

Pain and Disability in Low Back Pain Can be Reduced Despite No Significant Improvements in Mechanistic Pain Biomarkers.

OBJECTIVE: Altered balance in nociception in response to noxious stimuli is commonly reported in chronic low back pain (LBP). However, it is unclear whether an improvement in the clinical presentation is contingent on a reduction in pain sensitivity. This study investigated whether the quantitative sensory testing (QST) profile changes in people undergoing rehabilitation for LBP. DESIGN: A prospective, observational case-control study. METHODS: Forty males and females, 18 to 40 years' old (20 with LBP) participated in 2 sessions. QST was performed at baseline and after discharge from rehabilitation (LBP) or after 3 to 8 weeks (controls). The QST battery consisted of determining pressure-pain thresholds at the low back and shoulder, temporal summation of pain, and conditioned pain modulation. Questionnaire data was used to determine pain (Numeric Rating Scale [NRS]), disability (Roland-Morris Questionnaire [RMQ]), Fear Avoidance Beliefs (FABQ), and The Örebro Musculoskeletal Pain Screening Questionnaire (ÖMPSQ) at baseline and discharge. The treatment effect was determined by calculating the Cohen d. RESULTS: No significant group×time interactions or main factor effect was found for any of the QST measures. The LBP group reported a significant reduction in NRS (P<0.0002, d=1.23), RMQ (P<0.0001, d=1.58), FABQ (P<0.001, d=0.87), and in the ÖMPSQ (P<0.00001, d=1.44). CONCLUSIONS: The results indicate that an improvement of clinical LBP is not contingent upon changes in the pain sensory profile. The value of screening pain sensitivity in LBP patients in primary care, needs to be investigated further, due to the patient population heterogeneity and the sensitivity of assessment methods.

Changes in Pain Sensitivity and Conditioned Pain Modulation During Recovery From Whiplash-associated Disorders.

OBJECTIVE: The objective of this study was to investigate the pain-sensory profile of patients with whiplash-associated disorders (WADs) prior and post 2 weeks of standardized rehabilitation and after a 6-month follow-up. MATERIALS AND METHODS: Twenty-two WAD participants (grade II; 14 women) and 22 sex-matched and age-matched healthy pain-free controls were enrolled. Pressure pain thresholds (PPTs) were assessed at local and distal muscles. Conditioned pain modulation (CPM) of PPTs was assessed using cuff pressure around the upper arm. Referred area of pain following supra-threshold pressure stimulation of the infraspinatus muscle was recorded on a body chart. Psychometric variables (pain intensity, area of perceived pain, pain catastrophizing, kinesiophobia, sleep problems, and depression level) were assessed. WAD group additionally completed the Neck Disability Index. RESULTS: The WAD group demonstrated lower local PPTs compared with controls at all time points (P<0.05) and lower distal PPTs at baseline and at 2 weeks when compared with 6 months (within-group) (P<0.05). The WAD group had a reduced CPM response and larger induced referred pain areas compared with controls (P<0.05), while no within-group changes were observed at any time point. The WAD group reported higher pain intensity and perceived area of pain compared with controls at all time points (P<0.05) and a mean Neck Disability Index score of 41% at baseline, 16% at 2 weeks, and 4% at 6 months. Furthermore, the WAD group reported improvements in all other psychometric variables (P<0.05), although only pain catastrophizing levels were comparable to controls at 2 weeks. DISCUSSION: PPTs but not CPM improved in the WAD group and were comparable to controls following 2 weeks following standardized rehabilitation, indicating that normalization of CPM may not be required to recover from WAD.