Synopsis Manual therapy interventions are popular among individual health care providers and their patients; however, systematic reviews do not strongly support their effectiveness. Small treatment effect sizes of manual therapy interventions may result from a "one-size-fits-all" approach to treatment. Mechanistic-based treatment approaches to manual therapy offer an intriguing alternative for identifying patients likely to respond to manual therapy. However, the current lack of knowledge of the mechanisms through which manual therapy interventions inhibit pain limits such an approach. The nature of manual therapy interventions further confounds such an approach, as the related mechanisms are likely a complex interaction of factors related to the patient, the provider, and the environment in which the intervention occurs. Therefore, a model to guide both study design and the interpretation of findings is necessary. We have previously proposed a model suggesting that the mechanical force from a manual therapy intervention results in systemic neurophysiological responses leading to pain inhibition. In this clinical commentary, we provide a narrative appraisal of the model and recommendations to advance the study of manual therapy mechanisms. J Orthop Sports Phys Ther 2018;48(1):8-18. doi:10.2519/jospt.2018.7476.

Objective The aims of this study were to 1) examine the pattern of experimental pain responses in the affected and non-affected extremities in patients with shoulder pain and 2) explore the intra-individual association between sensitization states derived from experimental pain testing. Methods Experimental pain responses from 58 patients with shoulder pain (17 females, ages 18 to 52) were compared to those from 56 age- and sex-matched healthy volunteers (16 females, ages 21 to 58). Experimental pain responses included pressure pain threshold (PPT), thermal pain threshold and tolerance, and suprathreshold heat pain response (SHPR). Comparisons were made between the affected and non-affected extremity of clinical participants and the average response of extremities in healthy participants. Peripheral and central sensitization indexes were computed for clinical participants using standardized scores and percentile cut-offs based on the data from the healthy control sample. Experimental pain responses in clinical participants observed beyond the 25th and 75th percentile of healthy control sample responses were used for investigation of intra-individual association of sensitization states. Results PPT on the affected side acromion and masseter of clinical participants were diminished compared to their non-affected side (p < 0.015). Bilateral sensitivity in clinical participants was noted for PPT at the acromion and SHPR (p < 0.015). Peripheral and central sensitization indexes demonstrated that individuals with shoulder pain present with variable patterns of peripheral and central sensitization. Conclusions Collectively, experimental pain responses supported peripheral and central sensitization in response to pressure and thermal stimuli. No clear association was made between individuals exhibiting peripheral or central sensitization and suggests heterogeneity in pain processing in this clinical population.

No abstract

The amount and type of physical activity (PA) appropriate in youth for optimal health is still being discussed. The purpose of this study on 12-year-old preadolescents is to evaluate the association of two PA patterns, corresponding to different exercise intensities, with some health-related indexes. PA was evaluated by triaxial accelerometry in 67 student subjects, who were successively classified according to 1) their usual participation or not in moderately intense (> 4 metabolic equivalents, METs) activities (either in daily life or in leisure activities) for at least 210 min a week (4 M (210)); and 2) the habitual practice or not of more intense activities (> 6 METs) for at least 60 min a week (6 M (60)). Health-related indexes consisted of cardiopulmonary (maximum oxygen uptake, V.O 2max), muscular (lower limb strength) fitness parameters and vagal-related indexes of heart rate (HR) variability (HRV), such as the HF/(LF+HF) ratio (where HF and LF stand for high and low frequency power). HR was recorded in the supine position after 15 min of quiet rest, and HRV indexes were calculated in 5-min segments. Energy expenditure due to PA was not significantly associated with any health-related index. Reaching 4 M (210) was associated with both higher estimated V.O 2max (p < 0.05) and higher muscular strength indexes (p < 0.05) but not with enhanced HRV indexes. Subjects who reached 6 M (60) had higher estimated V.O2max (p < 0.05) and higher HF/(LF+HF) (p < 0.05). Our results show that regular moderately intense activities are sufficient to influence physical fitness but suggest that more intense activities are necessary to observe more favorable HRV vagal-related indexes.

Recently a clinical prediction rule (CPR) for lumbar regional spinal thrust manipulation (STM) has shown predictive success in patients with back pain who met specific selection criteria. The purpose of this study was to compare the effectiveness of STM and mechanical diagnosis and therapy (MDT) in patients who are positive for the STM CPR. Following initial examination, 31 participants were randomized to the STM group (n = 16) and to the MDT group (n = 15). Two weeks following initial examination, four participants chose to cross over from the STM group to the MDT group. The Oswestry Disability Index (ODI), Fear-Avoidance Beliefs Questionnaire work subscale (FABQw), and the Numerical Pain Rating Scale (NPRS) were administered initially, and at 2-weeks and 4 week follow-up (discharge). Data were analyzed to determine changes in ODI and NPRS scores from initial examination through one month. Of the 31 participants, one patient who met only three of five selection criteria and four others who chose to switch groups were removed from the analysis. Both groups exhibited statistically significant improvements in ODI and NPRS scores from baseline to final visit but there was no significant difference in scores between groups at 4 weeks. In this sample of patients, the selection criteria for this CPR were not exclusive for lumbopelvic STM. Mechanical diagnosis and therapy was an equally viable choice for these patients.