Search

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.

When a physical therapist provides a manual therapy (MT) intervention for a patient presenting with pain and the patient experiences a positive clinical outcome, we cannot answer as to why this occurs. Would we continue to devote valuable time and financial resources to learning and improving our skills in providing MT interventions if the related clinical outcomes were placebo responses? In this Viewpoint, the authors conceptualize placebo as an active and important mechanism of MT and argue that placebo mechanisms deserve consideration as an important component of the treatment effect. J Orthop Sports Phys Ther 2017;47(5):301-304. doi:10.2519/jospt.2017.0604.

Study Design: Single-blind randomized trial., Objectives: To compare the effects of cervical and shoulder thrust manipulation (TM) and exercise on pain sensitivity, and to explore associations with clinical outcomes in patients with shoulder pain., Background: Experimental studies indicate that spinal TM has an influence on central pain processes, supporting its application for treatment of extremity conditions. Direct comparison of spinal and peripheral TM on pain sensitivity has not been widely examined., Methods: Seventy-eight participants with shoulder pain (36 female; mean ± SD age, 39.0 ± 14.5 years) were randomized to receive 3 treatments of cervical TM (n = 26), shoulder TM (n = 27), or shoulder exercise (n = 25) over 2 weeks. Twenty-five healthy participants (13 female; mean ± SD age, 35.2 ± 11.1 years) were assessed to compare pain sensitivity with that in clinical participants at baseline. Primary outcomes were changes in local (eg, shoulder) and remote (eg, tibialis anterior) pressure pain threshold and heat pain threshold occurring over 2 weeks. Secondary outcomes were shoulder pain intensity and patient-rated function at 4, 8, and 12 weeks. Analysis-of-variance models and partial-correlation analyses were conducted to examine comparative effects and the relationship between measures., Results: At baseline, clinical participants demonstrated lower local (mean difference, - 1.63 kg; 95% confidence interval [CI]: -2.40, -0.86) and remote pressure pain threshold (mean difference, -1.96 kg; 95% CI: -3.09, -0.82) and heat pain threshold (mean difference, -1.15°C; 95% CI: -2.06, -0.24) compared to controls, suggesting enhanced pain sensitivity. Following intervention, there were no between-group differences in pain sensitivity or clinical outcome (P>.05). However, improvements were noted, regardless of intervention, for pressure pain threshold (range of mean differences, 0.22-0.32 kg; 95% CI: 0.03, 0.43), heat pain threshold (range of mean differences, 0.30-0.58; 95% CI: 0.06, 0.96), pain intensity (range of mean differences, -1.79 to -1.45; 95% CI: -2.34, -0.94), and function (range of mean differences, 3.15-3.82; 95% CI: 0.69, 6.20) at all time points. We did not find an association between pain sensitivity changes and clinical outcome (P>.05). Conclusion Clinical participants showed enhanced pain sensitivity, but did not respond differently to cervical or peripheral TM. In fact, in this sample, cervical TM, shoulder TM, and shoulder exercise had similar pain sensitivity and clinical effects. The lack of association between pain sensitivity and clinical pain and function outcomes suggests different (eg, nonspecific) pain pathways for clinical benefit following TM or exercise., Level of Evidence: Therapy, level 1b.

Study Design: Retrospective cohort., Objectives: The objectives of this study were (1) to examine patients' general expectations for treatment by physical therapists and specific expectations for common interventions in patients with neck pain, and (2) to assess the extent to which the patients' general and specific expectations for treatment, particularly spinal manipulation, affect clinical outcomes., Background: Patient expectations can have a profound influence on the magnitude of treatment outcome across a broad variety of patient conditions., Methods: We performed a secondary analysis of data from a clinical trial of interventions for neck pain. Prior to beginning treatment for neck pain, 140 patients were asked about their general expectations of benefit as well as their specific expectations for individual interventions. Next, we examined how these expectations related to the patients' ratings of the success of treatment at 1 and 6 months after treatment., Results: Patients had positive expectations for treatment by a physical therapist, with more than 80% of patients expecting moderate relief of symptoms, prevention of disability, the ability to do more activity, and to sleep better. The manual therapy interventions of massage (87%) and manipulation (75%) had the highest proportion of patients who expected these interventions to significantly improve neck pain. These were followed by strengthening (70%) and range-of-motion (54%) exercises. Very few patients thought surgery would improve their neck pain (less than 1%). At 1 month, patients who were unsure of experiencing complete pain relief had lower odds of reporting a successful outcome than patients expecting complete relief (odds ratio [OR] = 0.33; 95% confidence interval [CI]: 0.11, 0.99). Believing that manipulation would help and not receiving manipulation lowered the odds of success (OR = 0.16; 95% CI: 0.04, 0.72) compared to believing manipulation would help and receiving manipulation. Six months after treatment, having unsure expectations for complete pain relief lowered the odds of success (OR = 0.19; 95% CI: 0.05, 0.7), whereas definitely expecting to do more exercise increased the odds of success (OR = 11.4; 95% CI: 1.7, 74.7). Regarding self-reported disability assessed with the Neck Disability Index, patients who believed manipulation would help and received manipulation reported less disability than those who did not believe manipulation would help and both received manipulation (mean difference, -3.8; 95% CI: -5.9, -1.5; P = .006) and did not receive manipulation (mean difference, -5.7; 95% CI: -9.3, -2.1; P = .014). There was also an interaction between time and the expectation for complete relief., Conclusion: General expectations of benefit have a strong influence on clinical outcomes for patients with neck pain., Level of Evidence: Prognosis, level 2b-.

Study Design: Randomized, controlled trial., Objectives: To assess the believability of a novel sham intervention for a neurodynamic technique (NDT) in participants with signs and symptoms of carpal tunnel syndrome (CTS). Additionally, we wished to assess a potential mechanism of NDT (hypoalgesia) and to compare outcomes related to clinical pain and upper extremity disability between NDT and a sham intervention., Background: Preliminary evidence suggests that NDT is effective in the treatment of CTS. A sham-controlled study is lacking from the literature and could provide insight to the efficacy of NDT, as well as the corresponding mechanisms., Methods: Participants with signs and symptoms consistent with CTS provided baseline measures of expectation, clinical pain intensity, upper extremity disability, and experimental pain sensitivity. Participants were then randomly assigned to receive either a NDT known to anatomically stress the median nerve or a sham technique intended to minimize stress to the median nerve. Following brief exposure to the assigned technique, expectation was reassessed to observe for group-dependent changes. Participants received the assigned intervention over 3 weeks. Additionally, all participants received a prefabricated wrist splint for their involved hands, with instructions to sleep in the splint and to wear it during painful activities when awake. Following 3 weeks of the assigned intervention and splint wear, baseline measures were reassessed and participants were asked which intervention they believed they had received., Results: Forty females agreed to participate. Expectations for pain relief and perceived group assignment were similar between the groups. Within-session decreases in clinical pain intensity and pressure pain sensitivity were observed independent of group assignment. Reduction of temporal summation was observed only in participants receiving NDT. Significant improvements in clinical pain intensity and upper extremity disability were observed at 3 weeks, independent of group assignment., Conclusion: The sham intervention was successful in blinding the participants. Immediate changes in pain sensitivity and intensity and 3-week changes in clinical pain intensity and upper extremity disability associated with NDT were equivalent to a sham intervention to which the participants were adequately blinded. Conversely, reduction of temporal summation was only observed in participants receiving the NDT, suggesting the potential of a favorable neurophysiological effect.

Study Design: A single-blinded, quasi-experimental, within- and between-sessions assessment., Objectives: To investigate potential mechanisms of neural mobilization (NM), using tensioning techniques in comparison to sham NM on a group of asymptomatic volunteers between the ages of 18 and 50., Background: NM utilizing tensioning techniques is used by physical therapists in the treatment of patients with cervical and/or upper extremity symptoms. The underlying mechanisms of potential benefits associated with NM tensioning techniques are unknown., Methods and Measures: Participants (n = 62) received either a NM or sham NM intervention 2 to 3 times a week for a total of 9 sessions, followed by a 1-week period of no intervention to assess carryover effects. A-delta (first pain response) and C-fiber (temporal summation) mediated pain perceptions were tested via thermal quantitative sensory testing procedures. Elbow extension range of motion (ROM) and sensory descriptor ratings were obtained during a neurodynamic test for the median nerve. Data were analyzed with repeated-measures analysis of variance (ANOVA)., Results: No group differences were seen for A-delta mediated pain perception at either immediate or carryover times. Group differences were identified for immediate C-fiber mediated pain perception (P = .032), in which hypoalgesia occurred for the NM group but not the sham NM group. This hypoalgesic effect was not maintained at carryover (P = .104). Group differences were also identified for the 3-week and carryover periods for elbow extension ROM (P = .004), and for the participant sensory descriptor ratings (P = .018), in which increased ROM and decreased sensory descriptor ratings were identified in participants in the NM group but not the sham NM group., Conclusion: This study provides preliminary evidence that mechanistic effects of tensioning NM differ from sham NM for asymptomatic participants. Specifically, NM resulted in immediate, but not sustained, C-fiber mediated hypoalgesia. Also, NM was associated with increased elbow ROM and a reduction in sensory descriptor ratings at 3-week and carryover assessment times. These differences provide potentially important information on the mechanistic effects of NM, as well as the description of a sham NM for use in future clinical trials.

Study Design: Cross-sectional., Objectives: This study examined the baseline relationship of pain intensity, physical impairment, and pain-related fear to shoulder function., Background: There is no consensus regarding the influence psychological variable have on function and recovery in individuals with shoulder pathologies. While pain-related fear has been shown to predict disability for patients with low-back and cervical pain, this relationship has not been consistently reported for patients with shoulder pain., Methods and Measures: One hundred forty-two subjects (78 male, 64 female; mean age, 41.4 years) with nonoperative unilateral shoulder disorders were identified from a clinical database of impairment and outcome measures.Demographic information, duration of symptoms, mechanism of injury, pain intensity, pain-related fear, and range-of-motion (ROM) measures were collected. Self-report of function was measured with the Shoulder Pain and Disability Index (SPADI). Hierarchical regression analysis determined the proportions of explained variance in function., Results: Demographic variables (duration of symptoms, sex, age, and mechanism of injury) collectively contributed approximately 9% (P=.003) of the variance in function scores. Average pain intensity and flexion ROM contributed an additional 22% (P<.001) of the variance, and Tampa Scale of Kinesiophobia (TSK-11) scores contributed an additional 3% (P<.001). In the final parsimonious model, presence of symptoms longer than 3 months (beta=.23, P=.003), pain intensity (beta=.25, P=.002), shoulder flexion ROM index (beta=-.35, P=.001), and kinesiophobia (beta=.17, P=.026) explained 33% of the variance in SPADI function score (P<.001)., Conclusions: Presence of symptoms longer than 3 months, average pain intensity, flexion ROM index (strongest contributor in multivariate model), and fear-of-pain scores all contributed to baseline shoulder function. The immediate clinical relevance of these findings is unclear but they do provide direction for prospective studies.

Study Design: Nonexperimental., Objectives: To determine interrater and intrarater agreement for 2 methods of evaluating movement quality during 2 lower extremity functional tasks, and to descriptively compare levels of agreement between the 2 methods., Background: Clinicians typically use observational analysis to evaluate movement quality during functional tasks, but the extent of agreement is unknown., Methods and Measures: Twenty-five uninjured subjects performed 3 trials of unilateral squat and lateral step-down tasks. Three clinicians evaluated the trunk, pelvis, and hips for coronal plane and transverse plane movement deviations. Two rating methods were used: assessment of the entire movement ("overall method") and rating each segment individually ("specific method"). Movement deviation severity was rated using basic clinical guidelines and ratings were repeated from videotape. Percent agreement and weighted kappa coefficients were calculated between rater pairs and rating sessions. Generalized kappa coefficients were calculated across raters., Results: Interrater and intrarater percent agreement were higher using the overall method. Interrater weighted kappa coefficients were similar between rating methods (overall method, 0-0.55; specific method, 0.23-0.53). Intrarater weighted kappa coefficients were higher for the specific method (0.38-0.68) compared to the overall method (0.13-0.50). Generalized kappa coefficients were also higher for specific method compared to the overall method (unilateral squat, 0.19 and 0.01, respectively; lateral step-down, 0.22 and 0.18, respectively) and 95% confidence intervals remained above zero., Conclusions: Rating movement at body segments appears to result in agreement among raters that is better than chance. Neither rating method produced high agreement, indicating a need to develop more explicit criteria for rating movement deviation severity.