Assessment of shoulder pain in hemiplegia: Sensitivity of the ShoulderQ

Background.?The ShoulderQ is a structured questionnaire designed to assess timing and severity of hemiplegic shoulder pain (HSP), in order to target pain relief effectively. It includes both verbal and visual graphic rating scale questions, simply presented for patients with language/visuo-spatial deficits following stroke.

Objective.?To assess the sensitivity of the ShoulderQ to clinical improvement in shoulder pain following multi-disciplinary intervention.

Design and setting.?Retrospective analysis of serial questionnaires collected in the course of clinical treatment in an in-patient neurological rehabilitation unit.

Subjects and interventions.?Thirty consecutive adults with cognitive and communicative deficits, presenting with hemiplegic shoulder pain following acquired brain injury. Multi-disciplinary treatment was delivered through an integrated care pathway, and ShoulderQs recorded fortnightly, including at baseline and end of treatment.

Results.?Changes on visual graphic rating scale (VGRS) were associated with verbal reports of improvement (rho 0.665, p < 0.001). Patients were divided retrospectively on the basis of their overall clinical response into responders (n = 18) and non-responders (n = 12). Responders showed significant change in both VGRS and verbal scores, whereas the non-responder group did not. A change in summed VGRS score of ≥3 showed 77% sensitivity and 91.3% specificity for identifying the responders, with a positive predictive value of 93.3%. Summed VGRS scores of ≤2 had a negative predictive value of 73.3%.

Conclusion.?In this preliminary evaluation of clinical data, the ShoulderQ appears to provide a sensitive measure of shoulder pain which is responsive to change in pain experience for those able to complete the questionnaire, despite the difficulties that many of this group of patients may have in reporting their symptoms. Set alongside previously reported test-retest reliability, the results support the utility of the ShoulderQ as a simple and practical tool for evaluation of shoulder pain in patients with severe complex disabilities.     

超声介导药物（祛湿止痛液）联合肌电生物反馈对卒中后肩痛患者的肩痛、肩关节运动功能改善效果

目的 观察超声介导药物（祛湿止痛液）联合肌电生物反馈对卒中后肩痛患者的肩痛、肩关节运动功能改善效果。方法 选择2019年1月至2020年1月我院收治的60例卒中后肩痛患者作为研究对象,按照入院号奇偶数字法将其随机分为对照组和观察组,各30例。对照组采用肌电生物反馈治疗,观察组在对照组治疗基础上联合超声介导药物（祛湿止痛液）治疗。比较两组的肩痛程度、肩关节活动度、上肢功能、生命质量及日常生活能力。结果 治疗前,两组的肩痛程度VAS评分无显著差异（P>0.05）;治疗后2、4、8周,观察组的肩痛程度VAS评分低于对照组（P<0.05）。治疗前,两组的肩关节前屈、外展、外旋活动度无显著差异（P>0.05）;治疗后,两组的肩关节前屈、外展、外旋活动度均较治疗前增大,且观察组大于对照组（P<0.05）。治疗前,两组患者的FMA、CMS、肩关节Neer评分、QOL-BREF及Barthel指数评分无显著差异（P>0.05）;治疗后,两组的FMA、CMS、肩关节Neer评分、QOL-BREF及Barthel指数评分均较治疗前升高,且观察组均高于对照组（P<0.05...     

Sonography of the shoulder after arthrography (arthrosonography): preliminary results.

PURPOSE: The purpose of this study was to verify whether arthrosonography improves diagnostic accuracy in diseases of the shoulder and provides additional information for therapeutic planning, compared with conventional sonography. METHODS: We prospectively studied 113 consecutive patients with chronic shoulder pain. Sonography was performed before and after arthrography, with the radiologist blinded to the results of arthrography. When a rotator cuff tear was detected sonographically, its type, location, and size were recorded; we also evaluated any changes in the subacromial-subdeltoid bursa and any abnormalities in the biceps tendon sheath. The diagnostic accuracy of conventional sonography and arthrosonography was compared with that of arthrography for rotator cuff tear. Changes in the subacromial-subdeltoid bursa and biceps tendon sheath seen on conventional sonography were also compared with those seen on arthrosonography. RESULTS: The sensitivity and specificity of conventional sonography in the diagnosis of rotator cuff tear were 86% (25/29) and 95% (80/84), respectively; for arthrosonography, the values were 97% (28/29) and 95% (80/84), respectively. The differences in sensitivity and specificity for the 2 sonographic techniques were not statistically significant (p > 0.05). The accuracy in localizing the tear was also not significantly different between the 2 sonographic techniques. Synovial proliferation was more easily detected with arthrosonography than it was with conventional sonography in the subacromial-subdeltoid bursa (p < 0.01) and in the biceps tendon sheath (p < 0.0001). CONCLUSIONS: Our preliminary results suggest that although arthrosonography was not superior to conventional sonography in the diagnosis of rotator cuff tears, it may provide a better assessment of the size of tears and additional information about synovial proliferation in the subacromial-subdeltoid bursa and the biceps tendon sheath.     

A questionnaire survey of UK physiotherapists on the diagnosis and management of contracted (frozen) shoulder

Objective

To gain insights into the diagnosis and management of contracted (frozen) shoulder (CFS) in a sample of UK physiotherapists, underpinning the development of evidence-based clinical guidelines.

Methods

An anonymous online questionnaire was developed and distributed via iCSP, targeting physiotherapists who treat CFS. For treatments, respondents were invited to consider ‘pain-predominant’ and ‘stiffness-predominant’ scenarios, choose from listed treatment options, and specify any unlisted conservative options they might consider. Frequency analysis was used for closed-ended questions, and content analysis was used for open-ended questions.

Results

In total, 289 valid responses were received. All respondents thought that movement restriction informed diagnosis. Of those specifying the manner of testing movements, 98% (121/123) included passive testing. Of those describing specific patterns of restriction, 71% (93/131) emphasised external rotation. Fifty-four percent (152/282) of valid respondents would consider suggesting/requesting imaging investigations, usually to exclude bony abnormalities. For treatment, only 46 respondents reported considering any unlisted conservative options, usually liaison regarding medication. For pain-predominant CFS, the preferred physiotherapeutic options were advice/education (96%; 277/288), injection (80%; 230/288), gentle exercise (79%; 228/288), superficial heat/cold (69%; 199/288) and acupuncture (68%; 196/288). For stiffness-predominant CFS, the preferred options were stretching (93%; 268/288), advice/education (88%; 252/288), joint mobilisations (87%; 250/288), function-based exercises (75%; 216/288) and hands-on soft-tissue techniques (59%; 170/288). Some dissociation was noted between clinical practice and research evidence. Eighty-five percent (253/284) of respondents would consider referring for an orthopaedic opinion.

Conclusions

Acknowledging restricted passive external rotation (vs the capsular pattern) as diagnostic of CFS would standardise and might improve the clinical aspect of diagnosis. The value of X-rays in differential diagnosis was under-recognised. Modalities used to treat CFS were dichotomised by pain-predominant and stiffness-predominant classifications, which may be more useful than existing classifications.     

Review article: Best practice management of common shoulder injuries and conditions in the emergency department (part 4 of the musculoskeletal injuries rapid review series)

Shoulder injuries are a commonly presenting complaint to the ED. In the absence of an obvious deformity, they can be difficult to assess and definitively diagnose because of the multiple structures that cause shoulder pain, the acuity and severity of pain and the lack of range of motion in the ED setting. The quality of ED care provided to patients with musculoskeletal shoulder pain is crucial to ensure the best possible outcomes for the patient. This rapid review investigated best practice for the assessment and management of common shoulder injuries and conditions in the ED. Databases were searched in 2017, including PubMed, CINAHL, EMBASE, TRIP and the grey literature, including relevant organisational websites. Primary studies, systematic reviews and guidelines published in English‐language in the past 12 years that addressed the acute assessment, management, follow‐up plan or prognosis were considered for inclusion. Data extraction of included articles was conducted, followed by quality appraisal to rate the level of evidence. The search revealed 1902 articles, of which 73 were included in the review (n = 12 primary articles, n = 49 systematic reviews and n = 12 guidelines). This rapid review provides clinicians who manage shoulder dislocations, fractures and soft tissue injuries in the ED a summary of the best available evidence to enhance the quality of care for optimal patient outcomes. There is strong evidence to support taking a thorough history and physical examination, with cautious use of special tests because of their poor diagnostic accuracy. Key points regarding the diagnosis and management of these injuries are provided.     

Measuring the perceived impact of facilitation on implementing recommendations from external assessment: lessons from the Dutch visitatie programme for medical specialists

OBJECTIVE: To evaluate the impact of facilitation by management consultants on implementing recommendations from external quality assessment (visitatie). DESIGN: Data collection through a postal survey amongst 205 medical specialists, representing 50 hospital-based specialist groups in the Netherlands. SETTING: Under the auspices of the specialty societies of surgeons, paediatricians and gynaecologists, 25 groups were offered approximately 20 h of management consulting to support the implementation of recommendations for quality improvement and were compared to 25 specialist groups not receiving the support. INTERVENTION: The Quality Consultation (QC) took a site-specific multifaceted implementation approach. MAIN MEASURES: Self-reported degree of implementation of recommendations, specialists' judgement of implementation result and process; experienced obstructing factors in implementing recommendations. RESULTS: The response rate was 54% (n = 110). The supported specialist groups were more successful in partially or fully implementing the recommendations from external peer assessment: 66.1% vs. 53.8%. The implementation result and process were also rated significantly higher for the supported groups. The supported groups reported significantly less (P < 0.005) obstructing factors; in particular for the barriers 'expectation of implementation advantages', 'acceptance of the recommendations' and 'assessed self-efficacy'. The experienced obstructing factors are strongly related with the degree of implementation (spearman rho 0.57-32.5%). CONCLUSIONS: This study suggests QC is a powerful implementation strategy. It also shows the limitations of merely quantitatively analysing multifaceted strategies: it does not offer any insight into the 'black box' of the QC. It is recommended that these limitations are met by also exploring multifaceted strategies qualitatively.     

Immediate effects of active cranio-cervical flexion exercise versus passive mobilisation of the upper cervical spine on pain and performance on the cranio-cervical flexion test

This study compared the immediate effects of an assisted plus active cranio-cervical flexion exercise (exercise group) versus a passive mobilisation plus assisted cranio-cervical flexion (mobilisation group) on performance of the cranio-cervical flexion test (CCFT), cervical range of motion (ROM) and pain in patients with chronic neck pain. Eighteen volunteers with chronic idiopathic neck pain participated in the study and were randomised to one of the two intervention groups. Current level of pain, cervical ROM and pain perceived during movement, pressure pain threshold (PPT) and surface electromyography (EMG) during performance of the CCFT were measured before and immediately after the intervention. A significant reduction in resting pain and PPT measured over cervical sites was observed immediately following both interventions, although a greater change was observed for the exercise group. No change in cervical ROM was observed after either intervention. Reduced sternocleidomastoid and anterior scalene EMG amplitude were observed during stages of the CCFT but only for the participants in the active exercise group. Although both active and passive interventions offered pain relief, only the exercise group improved on a task of motor function highlighting the importance of specific active treatment for improved motor control of the cervical spine.     

The effects of active and passive participation in musical activity on the immune system as measured by salivary immunoglobulin A (SIgA)

The purposes of this study were (a) to determine if musical activity would produce a significant change in the immune system as measured by Salivary Immunoglobulin A (SIgA), and (b) to determine if active participation in musical activity had a significantly different effect on the immune system than passive participation. Thirty-three participants (28 women and 5 men) were randomly assigned to one of 3 groups, 2 experimental and 1 control. Active group participants participated in a 30-minute session where they played various percussive instruments and sang. Passive group participants listened to 30 minutes worth of live music. Saliva samples were taken before and after sessions and SIgA concentrations were determined using radial immunodiffusion technique. All groups were found to be significantly different from each other. SIgA levels of the active group showed a significantly greater increase than those of the passive group and the control group, suggesting that active participation in musical activity produces a greater effect on the immune system than passive participation.     

The Cerebral Palsy Kinematic Assessment Tool (CPKAT): feasibility testing of a new portable tool for the objective evaluation of upper limb kinematics in children with cerebral palsy in the non-laboratory setting

Purpose: Efficacy of treatment to improve upper-limb activity of children with cerebral palsy (CP) is typically evaluated outside clinical/laboratory environments through functional outcome measures (e.g. ABILHAND kids). This study evaluates CPKAT, a new portable laptop-based tool designed to objectively measure upper-limb kinematics in children with CP. Methods: Seven children with unilateral CP (2 females; mean age 10 years 2 months (SD 2 years 3 months), median age 9 years 6 months, range 6 years 5 months, MACS II–IV) were evaluated on copying, tracking and tracing tasks at their homes using CPKAT. CPKAT recorded parameters relating to spatiotemporal hand movement: path length, movement time, smoothness, path accuracy and root mean square error. The Wilcoxon signed ranks test explored whether CPKAT could detect differences between the affected and less-affected limb. Results: CPKAT detected intra-limb differences for movement time and smoothness (aiming), and path length (tracing). No intra-limb tracking differences were found, as hypothesised. These findings are consistent with other studies showing that movements of the impaired upper limb in unilateral CP are slower and less smooth. Conclusion: CPKAT provides a potential solution for home-based assessment of upper limb kinematics in children with CP to supplement other measures and assess functional intervention outcomes. Further validation is required.

• Implications for Rehabilitation

• This paper demonstrates the feasibility of evaluating upper limb kinematics in home using CPKAT, a portable laptop-based evaluation tool.

• We found that CPKAT is easy to set-up and use in home environments and yields useful kinematic measures of upper limb function.

• CPKAT can complement less responsive patient reported or subjectively evaluated functional measures for a more complete evaluation of children with cerebral palsy.

• Thus, CPKAT can help guide a multi-disciplinary team to more effective intervention and rehabilitation for children with cerebral palsy.

     

Outcome Assessment in Emergency Medicine—A Beginning: Results of the Council of Emergency Medicine Residency Directors (CORD) Emergency Medicine Consensus Workgroup on Outcome Assessment

This article is designed to serve as a guide for emergency medicine (EM) educators seeking to comply with the measurement and reporting requirements for Phase 3 of the Accreditation Council for Graduate Medical Education (ACGME) Outcome Project. A consensus workshop held during the 2006 Council of Emergency Medicine Residency Directors (CORD) "Best Practices" conference identified specific measures for five of the six EM competencies—interpersonal communication skills, patient care, practice-based learning, professionalism, and systems-based practice (medical knowledge was excluded). The suggested measures described herein should allow for ease in data collection and applicability to multiple core competencies as program directors incorporate core competency outcome measurement into their EM residency training programs.     

Development of the Video Assessment of Propensity to Use Emergency Restraints Scale (VAPERS): Results of the VAPERS Study Group

Background: Emergency physicians (EPs) may disagree on when or whether patients need restraints. There is no good objective measure of the likelihood of EPs to restrain patients. Objectives: To 1) develop a scale to determine the likelihood that an EP would restrain a patient, 2) develop subscale scoring, and 3) determine a shortened version that correlates highly with the full scale. Methods: This was a prospective cross sectional study. The Video Assessment of Propensity to use Emergency Restraints Scale (VAPERS), consisting of 17 scenarios utilizing actors, was videotaped to produce a research video assessment tool. The VAPERS was designed by development experts to reflect the spectrum of patients who are considered for restraint in an emergency department. The VAPERS was piloted among a 22‐member pilot panel of EPs (faculty and residents). The pilot panel was asked to determine the degree to which each video patient possessed the following patient characteristics: medical instability, trauma, belligerence, agitation, and altered mental status. Each “degree of characteristic” was measured on a separate 100‐mm visual analog scale. Participants were then asked whether or not they would restrain each patient and whether the patient exhibited the potential to harm him‐ or herself or others. VAPERS subscales were developed for the likelihood to restrain patients with each of the patient characteristics. Spearman correlations were used for all comparisons. Linear regression was used to determine which patient characteristics were most related to likelihood to restrain and to develop a reduced scale to predict the overall likelihood to restrain. Results: The overall VAPERS score ranged from 0 to 100, with a median of 50 (interquartile range [IQR], 24–88). The visual analog scale results of how likely each video patient possessed specific characteristics were as follows: medical instability ranged from 0 to 100 (median, 32; IQR, 12–64), trauma ranged from 0 to 69 (median, 0; IQR, 0–31), belligerence ranged from 20 to 93 (median, 28; IQR, 14–63), agitation ranged from 3 to 84 (median, 52; IQR, 23–72), and altered mental status ranged from 1 to 93 (median, 29; IQR, 16–69). Linear regression indicated that two characteristic variables (danger to self and degree of agitation) in the video scenarios were highly correlated (0.87) with overall likelihood to restrain. Based on the results, the authors developed a shortened video assessment tool consisting of five of the original videos that were highly correlated (R= 0.94) with the full VAPERS scale on overall likelihood to restrain. Conclusions: The VAPERS scale covers a wide range of important variables in emergency situations. It successfully measured likelihood to restrain in this pilot study for overall situations, and for subgroups, based on patient characteristics. A shortened five‐video VAPERS also successfully measured the overall likelihood to restrain.     

The Double-Line Sign: A False Positive Finding on the Focused Assessment with Sonography for Trauma (FAST) Examination

Background: Emergency physicians commonly perform Focused Assessment with Sonography for Trauma (FAST) examinations to evaluate for free intraperitoneal fluid. Many ultrasound findings can be misinterpreted as free fluid, resulting in false-positive FAST examinations. Objectives: To describe a previously unreported ultrasound finding that can be misinterpreted as free intraperitoneal fluid. Case Report: A 32-year-old man was stabbed in the left upper abdomen. A FAST examination was performed and a right perinephric fat pad was interpreted as showing free fluid in Morison's pouch. After transfer to a trauma center, a repeat FAST examination revealed no signs of intraperitoneal free fluid. Wound exploration showed no signs of penetration into the peritoneal cavity. Conclusions: When performing a FAST examination, a wedge-shaped hypoechoic area in Morison's pouch that is bounded on both sides by echogenic lines (the “FAST Double-Line Sign”) is likely to represent perinephric fat and may result in a false-positive FAST examination.     

The intersection of professionalism and interprofessional care: development and initial testing of the interprofessional professionalism assessment (IPA)

Valid assessment of interprofessional education and collaborative practice (IPECP) is challenging. The number of instruments that measure various aspects of IPECP, or in various sites is growing, however. The Interprofessional Professionalism Assessment (IPA) measures observable behaviors of health care professionals-in-training that demonstrate professionalism and collaboration when working with other health care providers in the context of people-centered care. The IPA instrument was created by the Interprofessional Professionalism Collaborative (IPC), a national group representing 12 entry-level health professions and one medical education assessment organization. The instrument was created and evaluated over several years through a comprehensive, multi-phasic process: 1) development of construct and observable behaviors, 2) instrument design, expert review and cognitive interviews, and 3) psychometric testing. The IPA contains 26 items representing six domains of professionalism (altruism and caring, excellence, ethics, respect, communication, accountability), and was tested by 233 preceptors rating health profession learners in the final year of their practical training. These preceptors represented 30 different academic institutions across the U.S., worked in various types of practice sites, and evaluated learners representing 10 different entry-level health professions. Exploratory factor analysis suggested four factors (communication, respect, excellence, altruism and caring) using 21 items with the least amount of missing data, and confirmed, for the most part, a priori expectations. Internal consistency reliability coefficients for the entire instrument and its four subscales were high (all greater than 0.9). Psychometric results demonstrate aspects of the IPA’s reliability and validity and its use across multiple health professions and in various practice sites.     

New insights in symptom assessment: the Chinese Versions of the Memorial Symptom Assessment Scale Short Form (MSAS-SF) and the Condensed MSAS (CMSAS)

There are very few symptom assessment instruments in Chinese. We present the validity and reliability of the Memorial Symptom Assessment Scale Short Form (MSAS-SF) and the Condensed Form MSAS (CMSAS) in Chinese cancer patients. The Chinese version of the 32-item MSAS-SF, a self-report measure for assessing symptom distress and frequency in cancer patients, was administered to 256 Chinese patients with colorectal cancer at a clinical oncology outpatient unit. Highly prevalent symptoms included worrying (59%), dry mouth (54%), lack of energy (54%), feeling sad (48%), feeling irritable (48%), and pain (41%). Both the MSAS-SF and CMSAS demonstrated good validity and reliability. For the MSAS-SF subscales, Cronbach alphas ranged from 0.84 to 0.91, and for CMSAS subscales, from 0.79 to 0.87. Moderate-to-high correlations of MSAS-SF and CMSAS subscales with appropriate European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 subscales (0.42–0.71, Ps < 0.001) indicated acceptable convergent validity. Low correlations with the Rosenberg Self-Esteem and Optimism Scale (0.22, P < 0.001) indicated divergent validity. MSAS subscales varied as expected with other Chinese scales—the Chinese Health Questionnaire (CHQ) and the Life Orientation Scale. Construct validity of both MSAS versions was demonstrated by effective differentiation between clinically distinct patient groups (Karnofsky scores <80% vs. ≥80% [P < 0.001]; no active treatment vs. active treatment [P < 0.002–0.034]; CHQ-12 scores ≤4 vs. CHQ-12 scores >4 [P < 0.001]). The Number of Symptoms subscale correlated appropriately with the EORTC QLQ-C30 function (−0.46 to −0.60, P < 0.001) and symptom scales (0.31–0.64, P < 0.001). The average time to complete the MSAS-SF was six minutes. The Chinese versions of the MSAS-SF and CMSAS are valid and practical measures. Further validation is needed for Chinese patients with other cancer types and with other symptom instruments.     

The QE Health Scale (QEHS): Assessment of the clinical reliability and validity of a spiritually based holistic health measure

Purpose.?To assess the clinical reliability and validity of a holistic health measure, the QE Health Scale (QEHS), for use with people with physical disabilities.

Method.?A test-retest design saw the QEHS administered and compared with established measures of health at admission and discharge from three-week inpatient rehabilitation programmes. Data was analysed by factor and correlation analysis. Clinician-reported credibility and usefulness of the theoretical basis of the QEHS, the QEHS itself, and Patient Profiles derived from the QEHS were also used to evaluate clinical validity.

Results.?The QEHS was judged to possess satisfactory reliability and validity.

Conclusion.?The QEHS is a clinically reliable, valid, credible and useful holistic health instrument to facilitate client-centred therapeutic interventions, inform decision-making and evaluate outcomes for people with physical disabilities.     

Test-retest and interobserver reliability of quantitative sensory testing according to the protocol of the German Research Network on Neuropathic Pain (DFNS): a multi-centre study

Quantitative sensory testing (QST) is an instrument to assess positive and negative sensory signs, helping to identify mechanisms underlying pathologic pain conditions. In this study, we evaluated the test-retest reliability (TR-R) and the interobserver reliability (IO-R) of QST in patients with sensory disturbances of different etiologies. In 4 centres, 60 patients (37 male and 23 female, 56.4 ± 1.9 years) with lesions or diseases of the somatosensory system were included. QST comprised 13 parameters including detection and pain thresholds for thermal and mechanical stimuli. QST was performed in the clinically most affected test area and a less or unaffected control area in a morning and an afternoon session on 2 consecutive days by examiner pairs (4 QSTs/patient). For both, TR-R and IO-R, there were high correlations (r = 0.80-0.93) at the affected test area, except for wind-up ratio (TR-R: r = 0.67; IO-R: r = 0.56) and paradoxical heat sensations (TR-R: r = 0.35; IO-R: r = 0.44). Mean IO-R (r = 0.83, 31% unexplained variance) was slightly lower than TR-R (r = 0.86, 26% unexplained variance, P < .05); the difference in variance amounted to 5%. There were no differences between study centres. In a subgroup with an unaffected control area (n = 43), reliabilities were significantly better in the test area (TR-R: r = 0.86; IO-R: r = 0.83) than in the control area (TR-R: r = 0.79; IO-R: r = 0.71, each P < .01), suggesting that disease-related systematic variance enhances reliability of QST. We conclude that standardized QST performed by trained examiners is a valuable diagnostic instrument with good test-retest and interobserver reliability within 2 days. With standardized training, observer bias is much lower than random variance.     

A preliminary investigation into the effects of active interferential current therapy and placebo on pressure pain sensitivity: a random crossover placebo controlled study

Objective

(1) To determine the effect of active and placebo interferential current on muscle pain sensitivity using an experimental mechanically induced pain model. (2) To evaluate the predictive role of expectations, gender, baseline muscle pain sensitivity, and intervention order on placebo response.

Design

Randomized placebo controlled cross-over trial.

Setting

University research laboratory.

Participants

Forty healthy volunteers (20 females, 20 males).

Interventions

Active interferential current, placebo (sham) interferential current, and no treatment/control were applied to the lumbar area on different days.

Main outcomes measures

Pressure pain thresholds and placebo response.

Results

The two-way ANOVA with repeated measures analysis determined a significant interaction between condition and time (P = 0.002). Pairwise comparisons found differences between active interferential and the control condition at 15 minutes into treatment (mean difference = 0.890 kg/cm², 95% CI 0.023 to 1.757, P = 0.043) and at 30 minutes into treatment (mean difference = 0.910 kg/cm², 95% CI 0.078 to 1.742, P = 0.028). The increase in pressure pain thresholds between the active interferential and the control condition (1.12 kg/cm²) was clinically meaningful. Logistic regression analysis showed that the condition sequence order was the only variable that predicted placebo response (odds ratio 9.7; P = 0.028). If a subject started the sequence receiving placebo treatment first, the odds of responding to placebo would be approximately 10 times higher (i.e. 90% probability of being a placebo responder) than that of starting with an active treatment.

Conclusions

Active interferential was more efficient than control condition in decreasing muscle pain sensitivity. Placebo interferential was not significantly different from control. Treatment sequence demonstrated a strong association with placebo response. These findings have implications for future research characterizing and identifying placebo responders in physiotherapy.