Effectiveness of the McKenzie Method of Mechanical Diagnosis and Therapy for Treating Low Back Pain: Literature Review With Meta-analysis

Study Design Literature review with meta-analysis. Background The McKenzie Method of Mechanical Diagnosis and Therapy (MDT), a classification-based system, was designed to classify patients into homogeneous subgroups to direct treatment. Objectives To examine the effectiveness of MDT for improving pain and disability in patients with either acute (less than 12 weeks in duration) or chronic (greater than 12 weeks in duration) low back pain (LBP). Methods Randomized controlled trials examining MDT in patients with LBP were identified from 6 databases. Independent investigators assessed the studies for exclusion, extracted data, and assessed risk of bias. The standardized mean difference (SMD) and 95% confidence interval were calculated to compare the effects of MDT to those of other interventions in patients with acute or chronic LBP. Results Of the 17 studies that met the inclusion criteria, 11 yielded valid data for analysis. In patients with acute LBP, there was no significant difference in pain resolution (P = .11) and disability (P = .61) between MDT and other interventions. In patients with chronic LBP, there was a significant difference in disability (SMD, -0.45), with results favoring MDT compared to exercise alone. There were no significant differences between MDT and manual therapy plus exercise (P>.05) for pain and disability outcomes. Conclusion There is moderate- to high-quality evidence that MDT is not superior to other rehabilitation interventions for reducing pain and disability in patients with acute LBP. In patients with chronic LBP, there is moderate- to high-quality evidence that MDT is superior to other rehabilitation interventions for reducing pain and disability; however, this depends on the type of intervention being compared to MDT. Level of Evidence Therapy, level 1a. J Orthop Sports Phys Ther 2018;48(6):476-490. Epub 30 Mar 2018. doi:10.2519/jospt.2018.7562.

Specific directional exercises for patients with low back pain: a case series

PURPOSE

To determine whether outcomes could be changed after poor response to non-specific exercise therapy when the prescription was changed to specific, directional-preference exercises (McKenzie method).

METHODS

Patients who participated in a randomized clinical trial (RCT) and the alternative care phase immediately following formed the cohort for this case series. In an earlier RCT, patients with directional preference were randomized to exercises/advice matched to their individual directional preference or to one of two unmatched protocols. The primary inclusion criterion for our case series was patient reports of being unchanged or worse following 2 weeks' treatment in the RCT. The secondary inclusion criterion was patient requests for "a change to one of the other stretching protocols to see if I can achieve better pain control." Patients meeting either of these criteria were offered matched exercises/advice if they had not previously received this intervention. Two-way repeated-measures ANOVA and McNemar tests compared outcomes during two consecutive time intervals: baseline to 2 weeks and 2 weeks to discharge. Dropouts were included in the intention-to-treat analysis.

RESULTS

Four patients from the matched group met the primary inclusion criterion of "unchanged" (none reported being worse); 10 additional patients requested alternative treatment for better pain control (secondary criterion). Eighty-five patients from the two unmatched treatment groups met all the inclusion criteria, and an additional 22 patients met only the secondary criterion. These patients were offered matched treatment, and 96 consented. Those reporting improvement or resolution of symptoms were 22 % in the first two weeks of unmatched care (during the RCT) compared to 84 % with matched care. Statistically significant and clinically meaningful changes occurred in all outcomes (p < 0.001) after receiving matched care, compared to clinically unimportant changes with previous unmatched care during the RCT.

CONCLUSIONS

Poor outcomes from non-specific/unmatched exercise protocols appeared to reverse when patients with directional preference were given sub-group-matched, direction-specific exercises. Because of the limitations of our study design, replication with a control group and longer-term follow-up are required to validate the findings.

Glass eels (Anguilla anguilla) have a magnetic compass linked to the tidal cycle

The European eel (Anguilla anguilla) has one of the longest migrations in the animal kingdom. It crosses the Atlantic Ocean twice during its life history, migrating between the spawning area in the Sargasso Sea and Europe, where it is widely distributed. The leptocephalus larvae drift with the Gulf Stream and other currents for more than a year and metamorphose into glass eels when they arrive on the continental shelf and move toward coastal areas. The mechanisms underlying glass eel orientation toward the coast and into freshwater systems are poorly known. However, anguillid eels, including the glass eel life stage, have a geomagnetic sense, suggesting the possibility that they use Earth's magnetic field to orient toward the coast. To test this hypothesis, we used a unique combination of laboratory tests and in situ behavioral observations conducted in a drifting circular arena. Most (98%) of the glass eels tested in the sea exhibited a preferred orientation that was related to the tidal cycle. Seventy-one percent of the same eels showed the same orientation during ebb tide when tested in the laboratory under a manipulated simulated magnetic field in the absence of any other cue. These results demonstrate that glass eels use a magnetic compass for orientation and suggest that this magnetic orientation system is linked to a circatidal rhythm.

Effect of Adding McKenzie Syndrome, Centralization, Directional Preference, and Psychosocial Classification Variables to a Risk-Adjusted Model Predicting Functional Status Outcomes for Patients With Lumbar Impairments

Study Design Retrospective cohort. Background Patient-classification subgroupings may be important prognostic factors explaining outcomes. Objectives To determine effects of adding classification variables (McKenzie syndrome and pain patterns, including centralization and directional preference; Symptom Checklist Back Pain Prediction Model [SCL BPPM]; and the Fear-Avoidance Beliefs Questionnaire subscales of work and physical activity) to a baseline risk-adjusted model predicting functional status (FS) outcomes. Methods Consecutive patients completed a battery of questionnaires that gathered information on 11 risk-adjustment variables. Physical therapists trained in Mechanical Diagnosis and Therapy methods classified each patient by McKenzie syndromes and pain pattern. Functional status was assessed at discharge by patient-reported outcomes. Only patients with complete data were included. Risk of selection bias was assessed. Prediction of discharge FS was assessed using linear stepwise regression models, allowing 13 variables to enter the model. Significant variables were retained in subsequent models. Model power (R(2)) and beta coefficients for model variables were estimated. Results Two thousand sixty-six patients with lumbar impairments were evaluated. Of those, 994 (48%), 10 (<1%), and 601 (29%) were excluded due to incomplete psychosocial data, McKenzie classification data, and missing FS at discharge, respectively. The final sample for analyses was 723 (35%). Overall R(2) for the baseline prediction FS model was 0.40. Adding classification variables to the baseline model did not result in significant increases in R(2). McKenzie syndrome or pain pattern explained 2.8% and 3.0% of the variance, respectively. When pain pattern and SCL BPPM were added simultaneously, overall model R(2) increased to 0.44. Although none of these increases in R(2) were significant, some classification variables were stronger predictors compared with some other variables included in the baseline model. Conclusion The small added prognostic capabilities identified when combining McKenzie or pain-pattern classifications with the SCL BPPM classification did not significantly improve prediction of FS outcomes in this study. Additional research is warranted to investigate the importance of classification variables compared with those used in the baseline model to maximize predictive power. Level of Evidence Prognosis, level 4. J Orthop Sports Phys Ther 2016;46(9):726-741. Epub 31 Jul 2016. doi:10.2519/jospt.2016.6266.

Treatment Effect Sizes of Mechanical Diagnosis and Therapy for Pain and Disability in Patients With Low Back Pain: A Systematic Review

BACKGROUND

Mechanical Diagnosis and Therapy (MDT) is a treatment-based classification system founded on 3 core principles: classification into diagnostic syndromes, classification-based intervention, and appropriate application of force. Many randomized controlled trials have investigated the efficacy of MDT for low back pain; however, results have varied. The inconsistent delivery of MDT across trials may explain the different findings.

OBJECTIVES

To compare treatment effect sizes for pain or disability between trials that delivered MDT consistent with the core principles of the approach and trials that met some or none of these principles.

METHODS

In this systematic review, databases were searched from inception to June 2018 for studies that delivered MDT compared to nonpharmacological, conservative control interventions in patients with low back pain and reported outcomes of pain or disability. Studies were classified as "adherent" (meeting the core principles of MDT) or "nonadherent" (using some or none of the principles of MDT). Data were extracted by 2 independent reviewers. Meta-regression procedures were used to analyze the effect of delivery mode on clinical outcomes, adjusting for covariates of symptom duration (less than or greater than 3 months) and control intervention (minimal or active).

RESULTS

Studies classified as adherent to the MDT approach showed greater reductions in pain and disability of 15.0 (95% confidence interval: 7.3, 22.7) and 11.7 (95% confidence interval: 5.4, 18.0) points, respectively, on a 100-point scale compared to nonadherent trials.

CONCLUSION

This review provides preliminary evidence that treatment effects of MDT are greater when the core principles are followed.

LEVEL OF EVIDENCE

Therapy, level 1a. J Orthop Sports Phys Ther 2019;49(4):219-229. Epub 13 Feb 2019. doi:10.2519/jospt.2019.8734.

Pain pattern classification and directional preference are associated with clinical outcomes for patients with low back pain

Pain Pattern Classification (PPC) and Directional Preference (DP) have shown merit as reliable and predictable clinical solutions to help reduce the burden posed by low back pain (LBP). We conducted a prospective, observational cohort study to verify the association between PPC, DP, and clinical outcomes. We hypothesized that (1) patients who demonstrated DP Centralization (CEN) would have lower pain intensity and disability at follow-up than patients who demonstrated Non-DP Non-CEN, and (2) the prevalence of DP at first examination would be lowest for patients with chronic LBP and are greater than 65 years old. First examination and follow-up data were completed by 639 patients. Clinical outcome measures, including pain intensity and disability, were collected at first examination and follow-up. Baseline comparisons were made between groups with first examination data only and groups with first examination data and follow-up data. A Pearson's chi-squared test was used to determine differences in prevalence rates for the categorical variables, and two-sample t-tests were used for the continuous variables. A Turkey's range test was used to determine differences in follow-up pain intensity and disability for LBP dual-classifications. Multiple regression was used to investigate DP prevalence considering risk adjusted factors. Overall prevalence of DP was 84.5% and prevalence was lowest for patients with sub-acute symptoms. No significant difference existed for the prevalence of DP for patients based on age. Patients classified as DP CEN had, on average, 1.99 pain intensity units less than patients classified as Non-DP Non-CEN at follow-up. Patients classified as DP CEN had, on average, 3.43 RMDQ units less than patients classified as Non-DP Non-CEN at follow-up.These findings support previous reports, verifying the association between LBP dual-classification schemes and clinical outcomes.

Directional preference and functional outcomes among subjects classified at high psychosocial risk using STarT

BACKGROUND AND PURPOSE

Physiotherapy has an important role in managing patients with non-specific low back pain who experience elevated psychosocial distress or risk for chronic disability. In terms of evidence-based physiotherapy practice, cognitive-behavioural approaches for patients at high psychosocial risk are the recommended management to improve patient treatment outcomes. Evidence also suggests that directional preference (DP) is an important treatment effect modifier for prescribing specific exercises for patients to improve outcomes. Little is known about the influence of treatment techniques based on DP on outcomes for patients classified as high psychosocial risk using the Subgroups for Targeted Treatment (STarT) Back Screening Tool. This study aimed to examine the association between functional status (FS) at rehabilitation discharge for patients experiencing low back pain classified at high STarT psychosocial risk and whose symptoms showed a DP versus No-DP.

METHODS

High STarT risk patients (n = 138) completed intake surveys, that is, the lumbar FS of Focus On Therapeutic Outcomes, Inc., and STarT, and were evaluated for DP by physiotherapists credentialed in McKenzie methods. The FS measure of Focus On Therapeutic Outcomes, Inc., was repeated at discharge. DP and No-DP prevalence rates were calculated. Associations between first-visit DP and No-DP and change in FS were assessed using univariate and multivariate regression models controlling for 11 risk-adjusted variables.

RESULTS

One hundred nine patients classified as high STarT risk had complete intake and discharge FS and DP data. Prevalence rate for DP was 65.1%. A significant and clinically important difference (7.98 FS points; p = .03) in change in function at discharge between DP and No-DP was observed after controlling for all confounding variables in the final model.

CONCLUSION

Findings suggest that interventions matched to DP are effective for managing high psychological risk patients and may provide physiotherapists with an alternative treatment pathway compared to managing similar patients with cognitive-behavioural approaches. Stricter research designs are required to validate study conclusions.

Directional preference of the wrist: a preliminary investigation

Background

Directional preference is a phenomenon that occurs in musculoskeletal disorders. It is associated with improved symptomatic and functional outcomes. Research has shown a 90% increase in the identification of directional preference in the peripheral joints between 2006 and 2012. There is currently no research analyzing if predictive variables exist for establishing directional preference.

Case Description

This report presents 19 consecutive patients with wrist pain. These patients were evaluated using a mechanical diagnosis and therapy (MDT)-based assessment. Patients were classified into the mechanical syndromes Derangement, Dysfunction, Postural, and Other. Patients classified with wrist Derangement were assessed for the presence of directional preference. Secondary analysis of predetermined variables was performed for association with directional preference. One case description was included to demonstrate MDT assessment, treatment, and clinical reasoning.

Results

Of the 19 patients evaluated, 15 (79%) were classified as having wrist Derangement. All patients with wrist Derangement demonstrated directional preference. Eight movements were found to establish directional preference. Each was unique with varying degrees of direction, load, and force.

Discussion

This report found directional preference to be higher (79%) than previously reported values. Historical and physical examination findings were analyzed to determine if there were associated variables of directional preference. Excessive mechanical stress was found to be the most associated factor in predicting directional preference. These findings may lead to a greater understanding of peripheral MDT assessment, which may lead to increased identification of directional preference and improved patient outcomes.

Level of Evidence

4.

Pain pattern classification and directional preference for patients with neck pain

Objectives: Pain Pattern Classification (PPC) and Directional Preference (DP) have been shown to be predictive of health care outcomes and serve to guide orthopedic clinical decision making. We conducted a prospective, observational cohort study to verify the association between PPC, DP, and clinical outcomes. Methods: Clinical outcome measures including pain intensity and disability were completed at first examination and follow-up by 335 patients. A Pearson's chi-squared test was used to determine differences in prevalence rates for the categorical variables, and two-sample t-tests were used to determine differences in rates for the continuous variables. A Tukey's range test was used to determine differences in follow-up pain intensity and disability for neck pain dual-classification schemes. Results: The prevalence of DP was 82.4%. The prevalence of CEN, Non-CEN, and Non-Classifiable (NC) was 15.2%, 42.1%, and 25.1%, respectively. The prevalence of DP was lowest for patients with sub-acute symptoms and who were <45 years old. Patients classified as DP CEN had, on average 2.62 NDI units less than patients classified as Non-DP. Patients classified as DP CEN had, on average, 0.90 pain intensity units less than patients classified as Non-DP at follow-up. Patients who demonstrated DP CEN did not have clinically significant lower pain intensity or disability at follow-up than patients who demonstrated Non-DP. Discussion: The results of this investigation need to be interpreted with caution with respect to the study design and it's subsequent strengths and limitations. Level of Evidence: 1b.

Directional preference constructs for patients' low back pain in the absence of centralization

Objectives: A detailed description of how Directional Preference (DP) constructs are measured could accelerate research to practice translation and improve research findings for Mechanical Diagnosis and Therapy (MDT) stakeholders. A secondary analysis of a prospective, observational cohort study was conducted to understand (1) the type and prevalence of DP constructs at first examination and (2) the relationships between DP constructs and clinical outcomes at follow-up. Methods: Data were collected and analyzed from 1485 consecutive patients who presented to outpatient, private practice clinics with primary complaints of non-specific low back pain (LBP); 400 patients met the inclusion criteria and completed first examination and follow-up data. Statistical analysis determined prevalence and the relationships between DP constructs at first examination and clinical outcomes at follow-up. Results: The primary findings in this investigation were that (1) the most prevalent DP constructs at first examination were related to range of motion (ROM) and pain intensity (Patient Reported Improvement in ROM (74.8%), Increase in Spine ROM (29.5%), and Pain Intensity Change (17.3%)), (2) all groups improved and made clinically meaningful improvements in disability and pain intensity at follow-up, (3) no clinically significant differences in disability or pain intensity were found between the groups at follow-up, and (4) 26.5% and 6.5% of patients exhibited a relative increase in lumbar spine extension and flexion ROM, respectively, post repeated movement testing on the first examination. Discussion: The findings in this study assist providers in making assessment and treatment decisions with their patients by offering insight regarding the most prevalent DP constructs typically found at the first examination and their subsequent association with outcome when Centralization (CEN) does not occur. Recommendations for researchers have been made to further explore the DP framework used in this study.

Directional preference of the extremity: a preliminary investigation

Background: Mechanical diagnosis and therapy (MDT) is a specific classification-based musculoskeletal examination and intervention system that uses repeated end range and sustained movement to classify patients into mechanical syndromes. Research has recently demonstrated increased prevalence, reliability, and efficacy of MDT syndromes in varied peripheral musculoskeletal populations. There is currently no research analyzing if predictive variables exist for establishing directional preference in peripheral joints, other than the wrist. The aim of this study was to examine the clinical application of predictive variables for establishing directional preference and spinal referral in patients with isolated peripheral joint pain. Case Description: Thirty-seven consecutive patients with isolated peripheral pain were evaluated and classified using MDT assessment. Secondary analysis of predetermined variables was performed for association with directional preference and identification of spinal referral in Derangement syndrome. Results: All 37 patients were classified using MDT assessment. Thirty-three (89.2%) were classified as Derangement syndrome: 17 as spinal Derangement (45.9%) and 16 as peripheral Derangement (43.2%). One peripheral derangement also had an underlying Articular Dysfunction. Additionally, there were four patients classified as Other (10.8%). Discussion: Historical and physical examination findings were analyzed to determine if there were associated variables of directional preference or spinal referral. Mechanical stress was found to be the most associated factor in predicting directional preference. No peripheral movement loss, paresthesia, and constant pain were more associated with spinal referral. These findings may lead to a greater understanding of peripheral MDT assessment, which may lead to increased identification of directional preference and improved patient outcomes. Level of Evidence: 4.

Mechanical diagnosis and therapy and Morton's neuroma: a case-series

Objectives: Morton's neuroma (MN) is a neuralgia involving the common plantar digital nerves of the metatarsal region. Evidence-based treatment options for MN are sparse, and utility of physical therapy (PT) is unknown. Mechanical Diagnosis and Therapy (MDT) is a classification system utilizing direction-specific treatment for orthopedic conditions based on mechanical and symptomatic response to repeated end range movements. The purpose of this case series is to describe the management of three patients with a medical diagnosis of MN using the MDT classification system.Methods: Three female patients aged 54-75 years with unilateral plantar forefoot pain for 6 weeks to 8 years were referred by a podiatrist following positive clinically accepted diagnostic criteria for MN including radiological imaging and provocation testing. Patients were evaluated and treated utilizing MDT assessment and treatment principles. The intervention consisted of repeated movements matched to the patient's directional preference at either the lumbar spine (1 patient) or distal extremity (2 patients).Results: Immediate and one-year outcomes were excellent, demonstrating rapid and lasting improvement. Following discharge, the patients have been asymptomatic or able to self-manage without seeking additional medical intervention for this condition. Total visit frequency per patient averaged 2-3 visits total across 8-16 days.Discussion: Responses to repeated end range movements testing allowed for classification and prescription of exercise to rapidly improve symptoms and function in three patients referred to PT services with medically diagnosed MN. This series provides preliminary evidence that MDT may be effective in classifying and treating patients with MN.

Factors in Patient Responsiveness to Directional Preference-Matched Treatment of Neck Pain With or Without Upper Extremity Radiation

PURPOSE

Patient-related predictive factors in responsiveness to directional preference therapy for neck pain with or without upper extremity radiation (NP/R) have not been reported. A directional preference is any neck movement that, when performed repeatedly to end range, results in centralization and/or alleviation of NP/R. It was hypothesized that patient compliance with a prescribed, directional preference-matched home exercise program would improve positive responsiveness to NP/R treatment.

METHODS

Patient-related factors thought to affect responsiveness to care were collected retrospectively from charts and de-identified for patients with NP/R who underwent chiropractic treatment at a multispecialty spine clinic from January 2014 through June 2015. Responsiveness was measured by calculating the percentage change in Neck Bournemouth Questionnaire (NBQ) scores over treatment time. Multiple linear regression was used to identify factors associated with positive responsiveness.

RESULTS

Mean percentage change in patient NBQ score from initial intake to discharge was 50% (standard deviation: 32%). Of 104 patients meeting study inclusion criteria, 86 (83%) reported experiencing improvement after the first treatment session. Bivariate analysis of patient characteristics by compliance with directional preference-matched exercise indicated that compliant patients (n=95, 91%) demonstrated significantly greater responsiveness to care than did noncompliant patients, at 55% versus 25% change in NBQ score, respectively (P=0.0041). Four factors were statistically significant predictors of patient responsiveness to directional preference therapy for NP/R: patient compliance with directional preference-matched exercise (P=0.0023), patient age (P=0.0029), condition chronicity (P<0.0001), and whether the patient reported improvement of symptoms following initial treatment session (P=0.0003).

CONCLUSIONS

The results of this study suggest that patient compliance with directional preference exercise is associated with patient responsiveness to conservative treatment of NP/R, as are age, chronicity and report of immediate symptom improvement.

Classification by pain pattern for patients with cervical spine radiculopathy

OBJECTIVES

A prospective observational cohort study was conducted to (1) report the prevalence of Mechanical Diagnosis and Therapy (MDT) classifications, Centralization (CEN), and Non-CEN among patients with Cervical Spine Radiculopathy (CSR), and (2) describe the association between classification via CEN and Non-CEN and clinical outcomes at follow-up.

METHODS

Data were collected from 680 consecutive patients who presented to outpatient, orthopedic physical therapy clinics with primary complaints of neck pain with and without radiculopathy; thirty-nine patients (6%) met the physical examination inclusion criteria for CSR. First examination and follow-up data were completed by 19 patients.

RESULTS

Seventy-nine percent of patients' conditions were classified as Reducible Derangement at first examination and 21% were classified as either Irreducible Derangement, Entrapment, or Mechanically Inconclusive. The prevalence of CEN and Non-CEN was 36.8% and 47.4%, respectively. All patients treated via MDT methods made clinically significant improvements in disability, but not pain intensity, at follow-up. The magnitude of change in clinical outcomes was greatest for patients who exhibited CEN; however, the changes in disability and pain intensity at follow-up were not statistically significant compared to patients who exhibited Non-CEN at first examination. Patients who exhibited CEN were discharged, on average, ten days earlier and had one less treatment visit compared to patients who exhibited Non-CEN.

DISCUSSION

The findings of this study show that patients with CSR can be classified and treated via MDT methods and experienced clinically significant improvements in disability, but not pain intensity, at follow-up. Providers should consider MDT classification and treatment to improve clinical outcomes for their patients affected by CSR.

A prospective study of patients with shoulder pain and Mechanical Diagnosis and Therapy (MDT)

Objectives: A prospective observational cohort study was conducted to (1) determine the prevalence of Mechanical Diagnosis and Therapy (MDT) syndromes for patients with shoulder impairments and (2) report the interaction between MDT classification and clinical outcomes, including pain intensity and disability, at discharge.Methods: Clinical outcome measures were completed at intake and discharge by 115 patients. A two-way mixed model analysis of variance with subsequent pairwise comparisons was done to examine differences in clinical outcomes between the following MDT classifications: Shoulder Derangement, Shoulder Dysfunction, and Other.Results: The primary findings were that (1) 44.3 (35.3, 53.4), 40.0 (31.0, 48.9), and 15.6 (9.0, 22.3) percent of patients' conditions were classified as Shoulder Derangement, Shoulder Dysfunction, and Other, respectively, (2) all groups managed via MDT methods made clinically significant improvements in disability and pain intensity at discharge, (3) a statistically significant difference in pain intensity at discharge was observed between the Shoulder Derangement and the Shoulder Dysfunction classifications (p = 0.01), and (4) patients with the Shoulder Derangement classification were discharged, on average, 35.3 days earlier than the Shoulder Dysfunction classification and 28.3 days earlier than the Other classification.Discussion: This study confirms previous reports that the Shoulder Derangement and Shoulder Dysfunction classifications are common and represent distinct clinical trajectories when assessed and managed via MDT methods.

Physiotherapy assessment and treatment of chronic subjective tinnitus using mechanical diagnosis and therapy: a case report

Objectives: Tinnitus is the perception of sound without any external auditory stimulus. Cervicogenic somatic tinnitus (CST) is a subset in which symptoms are modulated by maneuvers of the neck. The evidence for effective diagnosis and treatment of CST is limited. Mechanical Diagnosis and Therapy (MDT) is a biopsychosocial assessment and management system that uses the response to mechanical forces to classify clinical presentations accurately. The purpose of this case report is to describe the MDT assessment and management of a patient with chronic subjective tinnitus.Methods: A 67-year-old female with a 5-year history of left-sided subjective tinnitus, neck pain, and headache was referred for physiotherapy. Outcome measures included the Visual Analogue Scale (VAS), Tinnitus Handicap Inventory (THI), and Neck Disability Index (NDI). She was evaluated and treated according to MDT principles with management consisting of individualized directional preference exercises and postural correction.Results: Significant improvements in symptoms, cervical range of motion, function, and psychosocial status were observed over the long-term. At 6 months, THI scores dropped from 62/100 to 18/100 and NDI scores dropped from 18/50 to 3/50.Discussion: A comprehensive MDT assessment led to a classification of Derangement, with treatment focusing on tailored self-management. Contrary to other interventions described for CST, the patient was able to make significant and lasting changes to her symptoms without the need for any externally applied interventions. The emphasis on self-management dovetails well with the biopsychosocial model of care. This case provides preliminary evidence for the utility of screening for Derangement in conservative tinnitus assessments.Level of Evidence: 4.

A prospective study of patients with knee pain and mechanical diagnosis and therapy (MDT) classification

OBJECTIVES

A prospective observational cohort study was conducted to 1) determine the prevalence of Mechanical Diagnosis and Therapy (MDT) syndromes for patients with knee impairments, and 2) report the interaction between MDT classification and clinical outcomes, including pain intensity and disability, at discharge.

METHODS

Clinical outcome measures were completed at intake and discharge on 186 patients. A two-way mixed model analysis of variance with subsequent pairwise comparisons was done to examine differences between the following MDT classifications: Knee Derangement, Knee Dysfunction, and Other.

RESULTS

The primary findings were that: 1) 61.3% (54.3, 68.3), 9.7% (5.4, 13.9), and 29.0% (22.5, 35.5) of patients' conditions were classified as Knee Derangement, Knee Dysfunction, and Other, respectively; 2) all groups managed via MDT methods made clinically significant improvements in disability and pain intensity at discharge with the exception of the Other classification for pain intensity (NPRS difference score = 1.8); 3) a clinically significant difference was observed between the Knee Derangement and Other for pain and between the Knee Derangement and Other and the Knee Dysfunction and Other classifications for disability; and 4) the Knee Derangement classification was discharged, on average, 15.8 days earlier than the Knee Dysfunction classification.

DISCUSSION

This was the first prospective study of the application of MDT in patients with knee impairments. Results should be interpreted with caution as follow-up data were only completed on 58% of patients that started data collection. Assuming that none of the dropouts were Derangement, the overall prevalence of Derangement would be 32.2% and 79.7% if all dropouts were classified as Derangement. This study adds insight into understanding the unique clinical trajectories of these MDT classifications for the knee and offers recommendations for future work in this growing field of research.

Directional preference constructs for patients' neck pain in the absence of centralization

Objectives: We conducted a secondary analysis of a prospective, observational cohort study to (1) report the prevalence of Directional Preference (DP) constructs at first examination for patients with cervical spine challenges, and (2) determine the association between DP constructs and clinical outcomes at discharge from physical therapy. Methods: We analyzed data collected from 718 consecutive patients who presented to outpatient, private practice clinics with primary complaints of non-specific neck pain; 200 patients met the inclusion criteria and completed first examination and discharge data. Statistical analysis determined the association between DP constructs at first examination and clinical outcomes at discharge. Results: The findings in this investigation were that (1) the most prevalent DP constructs at first examination were related to ROM and pain intensity including Patient Reported Improvement in ROM (79.5%), Increase in Spine ROM (32.5%), and Pain Intensity Change (15.0%), (2) all DP groups improved and met the MCID for disability and pain intensity change at discharge except for the group that did not exhibit Increase in Spine ROM for pain intensity, (3) no clinically significant differences in pain intensity or disability existed between DP groups at discharge, and (4) 28.5% and 6.5% of patients exhibited a relative increase in cervical spine extension and flexion ROM, respectively, post-repeated movement testing on the first examination. Discussion: The most prevalent DP constructs at first examination were related to ROM and pain intensity, and each was associated with a comparable clinical trajectory in terms of pain and disability outcomes at discharge. The findings of this study help Mechanical Diagnosis and Therapy (MDT) providers understand the common DP constructs encountered in routine clinical practice and their relation to pain and disability outcomes for patients with cervical spine challenges. Level of Evidence: 2b.

Utilization of the Cervical Flexion Rotation Test to Confirm Rotation Directional Preference in People With Neck Pain: A Case Series

Despite the prevalence of neck pain, evidence is lacking regarding the relationship of pathophysiology to function in people with neck conditions. Although movement-based diagnoses based on directional preference (DP) are described for lumbar spinal conditions, how these diagnoses guide interventions is not supported in the Cervical Spine Clinical Practice Guidelines. To date, there are no case studies in the literature that demonstrate the efficacy of cervical spine management based on a rotation DP. This case series highlights patient response to repeated end-range neck movements to inform DP and how the cervical flexion rotation test (CFRT) was used as a clinical baseline to assess mechanical and symptomatic changes. Three consecutive patients were evaluated by a physical therapist fellow trained in orthopedic manual physical therapy and diplomaed in mechanical diagnosis and therapy. The patients' baseline pain ranged from 3 to 7/10 on the Numerical Pain Rating Scale (NPRS), and disability scores ranged from 20% to 52.6% on patient-reported outcome (PRO) measures. All three cases demonstrated a limited and painful CFRT. Examination procedures included repeated end-range movement testing in the sagittal and frontal and transverse planes. Across five to six visits in five to eight weeks, a decrease in the primary outcome measures from baseline to discharge were observed: NPRS, 50-85%; PRO, 60-82%. The CFRT may be a key baseline when screening patients with neck pain for DP. Following repeated end-range sagittal and frontal plane movements, the rapid change in the CFRT following targeted upper cervical rotation techniques confirmed a rotation DP.

Neural Interruption by Unilateral Labyrinthectomy Biases the Directional Preference of Otolith-Related Vestibular Neurons

Background: The directional preference of otolith-related vestibular neurons elucidates the neuroanatomical link of labyrinths, but few direct experimental data have been provided. Methods: The directional preference of otolith-related vestibular neurons was measured in the vestibular nucleus using chemically induced unilateral labyrinthectomy (UL). For the model evaluation, static and dynamic behavioral tests as well as a histological test were performed. Extracellular neural activity was recorded for the neuronal responses to the horizontal head rotation and the linear head translation. Results: Seventy-seven neuronal activities were recorded, and the total population was divided into three groups: left UL (20), sham (35), and right UL (22). Based on directional preference, two sub-groups were again classified as contra- and ipsi-preferred neurons. There was no significance in the number of those sub-groups (contra-, 15/35, 43%; ipsi-, 20/35, 57%) in the sham (p = 0.155). However, more ipsi-preferred neurons (19/22, 86%) were observed after right UL (p = 6.056 × 10⁻⁵), while left UL caused more contra-preferred neurons (13/20, 65%) (p = 0.058). In particular, the convergent neurons mainly led this biased difference (ipsi-, 100% after right UL and contra-, 89% after left UL) (p < 0.002). Conclusions: The directional preference of the neurons depended on the side of the lesion, and its dominance was mainly led by the convergent neurons.

Virtual McKenzie extension exercises for low back and leg pain: a prospective pilot exploratory case series

INTRODUCTION

Current evidence supports the inclusion of directional preference exercises for a subgroup of patients with low back (LBP) and leg pain. Recent pain neuroscience strategies have suggested that cortical restructuring associated with movement activating the body map representation in the brain might account for the observed improvement with the directional preference approach.

OBJECTIVES

To explore whether or not a motor imagery directional preference approach would result in any changes in patients with LBP and leg pain.

METHODS

A consecutive convenience sample of patients with LBP and leg pain were recruited at two outpatient physical therapy clinics. Measurements of LBP, leg pain, fear-avoidance beliefs (FABQ), pain catastrophizing (PCS), active lumbar flexion, and straight leg raise (SLR) were compared before and immediately after a virtual (motor imagery) directional preference exercise.

RESULTS

Statistically significant differences for LBP, FABQ, PCS, active lumbar flexion, and SLR were observed, but only SLR changes met or exceeded the minimally clinically important difference (MCID).

CONCLUSIONS

A brief virtual motor imagery extension treatment yielded some immediate positive shifts in patients presenting to physical therapy with LBP and leg pain. Our results indicate that randomized comparison trials are needed to determine the effect of this intervention on the short- and longer-term outcomes in patients with LBP and leg pain.

Management of concussion symptoms utilizing Mechanical Diagnosis and Therapy: a case series

OBJECTIVE

Concussions are a common condition in athletes leading to symptoms including headache, dizziness, and sometimes vestibular deficits. Concussion management typically involves rest and a gradual return to activity among other interventions. This case series includes three patients who were evaluated using Mechanical Diagnosis and Therapy (MDT) after sport-related injuries involving concussion-like symptoms. MDT is a system of evaluating patients using repeated movements and sustained positions to assess symptomatic and mechanical changes.

RESULTS

Patients in this case series demonstrated rapid reduction of symptoms using variations of repeated cervical movements and sustained positions, which enabled them to return to play with a lasting resolution of symptoms.

DISCUSSION/CONCLUSION

This highlights the importance of a classification system for the appropriate treatment of these cases who did not require management using concussion protocol, as they were classified as cervical derangement.

The McKenzie Method delivered by credentialed therapists for chronic low back pain with directional preference: systematic review with meta-analysis

OBJECTIVE

To determine the effectiveness of the McKenzie Method compared to any conservative interventions on pain and disability in patients with chronic low back pain (LBP) with directional preference (DP).

METHODS

We searched six electronic databases up to September 2022. Eligible randomized controlled trials were those assessing the McKenzie Method delivered by credentialed therapists for chronic LBP with DP. Two reviewers independently selected studies, extracted data, assessed risk of bias with the revised Cochrane Risk of Bias 2.0 tool and certainty of evidence with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

RESULTS

Five trials (n = 743) were included. There was low-certainty evidence that the McKenzie Method, compared to all other interventions combined, produced clinically important reductions in short-term pain (mean difference [MD] -1.11 points on a 10-point scale; 95% CI -1.83 to -0.40) and in intermediate-term disability (standardized mean difference [SMD] -0.53; 95% CI -0.97 to -0.09). Low-to-moderate certainty evidence showed that the McKenzie Method also resulted in clinically important improvements in short-term pain (MD -1.53; 95% CI -2.51 to -0.54) and disability (SMD -0.50; 95% CI -0.74 to -0.25) when compared specifically to other exercise approaches, and in intermediate-term pain (MD -2.10; 95% CI -2.94 to -1.26) and disability (SMD -1.01; 95% CI -1.58 to -0.43) as well as long-term disability (SMD -0,59; 95% CI -1.14 to -0.03) when compared to minimal intervention. Low-certainty evidence showed usually small, clinically unimportant effects in comparison to manual therapy.

CONCLUSION

We found low-to-moderate certainty evidence that the McKenzie Method was superior to all other interventions combined for up to 6 months for pain and up to 12 months for disability, with clinically important differences versus exercise in the short term and versus minimal interventions in the intermediate term. The only clinically important long-term effect was on disability compared to minimal intervention.