Inter-rater reliability of Mechanical Diagnosis and Therapy (MDT) in evaluating and classifying chronic pelvic pain syndrome

Introduction Chronic pelvic pain syndrome (CPPS) involves complex interactions between the musculoskeletal system, nervous system, and psychosocial factors. A major challenge in managing CPPS is the lack of reliable assessment and classification systems. The Mechanical Diagnosis and Therapy (MDT) is a widely used and reliable classification system for assessing and managing painful musculoskeletal conditions affecting the spine and extremities. This study’s primary objective was to assess the inter-rater reliability of the MDT assessment in diagnosing CPPS using clinical vignettes. Secondary objectives included determining the prevalence of MDT classification categories.

Five MDT clinicians classified clinical vignettes into three categories: 1) Spinal Derangement, 2) Pelvic Floor Contractile Dysfunction, or 3) MDT OTHER subgroups. The vignettes were developed from the McKenzie Pelvic Pain Assessment Form. Inter-rater reliability among clinicians was calculated using the Fleiss kappa statistic with 95% confidence intervals, and Cohen’s kappa examined reliability between pairs of raters.

A total of 76 vignettes were developed (40 females and 36 males). Good inter-rater reliability was found among clinicians (Fleiss kappa = 0.616, 95% CI = 0.598–0.633, p < 0.001). Inter-rater reliability was higher when classifying female vignettes (Fleiss kappa = 0.658, 95% CI = 0.634, 0.682) than male vignettes (Fleiss kappa = 0.546, 95% CI = 0.519, 0.573). The most common classification was Spinal Derangement (57%), followed by MDT OTHER subgroups (26%) and Pelvic Floor Contractile Dysfunction (17%).

The study indicates good inter-rater reliability among MDT clinicians in classifying pelvic pain syndrome. However, clinical vignettes may not fully capture the complexities of real participant interactions, potentially inflating agreement. Future studies should incorporate direct observation of real participant encounters alongside clinical vignettes to improve validity.

Chronic pelvic pain syndrome, Mechanical Diagnosis and Therapy, inter-rater reliability, clinical vignette

Chronic pelvic pain syndrome (CPPS) is a prevalent and incapacitating condition that afflicts both males and females, resulting in substantial impairments in their quality of life [1–3]. CPPS is characterized by persistent or recurrent episodes of pelvic pain and is often accompanied by lower urinary tract, sexual, bowel, gynecological, and psychosocial issues, without any evidence of infection or other underlying pathologies [4]. It is estimated that CPPS affects approximately 8–24% of individuals in the United States, with higher prevalence often reported in women compared to men [1–3]. The economic burden associated with CPPS is comparable to other prevalent conditions such as low back pain (LBP), fibromyalgia, and rheumatoid arthritis, encompassing both direct healthcare costs and indirect costs related to productivity loss [5]. CPPS is characterized by a multifaceted array of symptoms that often extends beyond the boundaries of the pelvis [6]. Research reveals that 75% of individuals with CPPS experience pain in areas other than the pelvis, with only a minority experiencing pain localized within the pelvis [6]. Moreover, 38% of patients report widespread pain [6]. This subgroup of patients may not benefit from pelvic-directed treatments alone, highlighting the need for a comprehensive approach to address their complex pain experiences [6]. A one-size-fits-all approach may lead to less favorable outcomes, as individual patients may require different interventions based on their pain patterns, etiology, and contributing factors [6]. Therefore, reliable classification of CPPS plays a pivotal role in ensuring targeted and effective treatment strategies [7]. As CPPS encompasses a broad spectrum of presentations, it is challenging to categorize patients into specific pathoanatomical subtypes [8]. Therefore, a non-pathoanatomical classification system becomes crucial for identifying the most appropriate and cost-effective interventions. The etiopathogenesis of CPPS remains an area of ongoing research. There is growing recognition that CPPS shares similarities with other neuromusculoskeletal pain disorders like lower back pain, indicating a common underlying pathogenesis [9–11]. The complexity of CPPS involves intricate interactions between the musculoskeletal system, nervous system, and psychosocial factors [9–11]. However, the existing literature reveals a predominant focus on normalizing pelvic floor function, while spinal screening procedures are rarely mentioned [2,12,13]. Since the spine has been documented as a potential source of pain, it is crucial to rule out spinal involvement in cases of pelvic pain [14,15]. Additionally, the current reliance on palpation-based assessment for evaluating pelvic floor dysfunction in the context of pelvic pain presents several limitations, as there is unacceptable inter-rater and intra-rater reliability in this assessment method [16–18]. Variability in palpation techniques, clinician experience, patient positioning, and other patient-related factors introduces subjectivity and potential biases. As well, studies have demonstrated that the association between a patient’s symptoms and pelvic floor abnormalities based on palpation is not consistently clear [17]. Given these limitations, there is a clear need for a more valid and reliable approach that utilizes clear diagnostic criteria and provides prognostic value for assessing pelvic floor dysfunction in the context of pelvic pain. Mechanical Diagnosis and Therapy (MDT) is a widely utilized non-anatomic classification system employed for assessing and managing painful musculoskeletal conditions affecting the spine and extremities [19–21]. MDT aims to classify patients into subgroups by evaluating their symptomatic and mechanical responses to movements, postures, and loading strategies. Extensive research has demonstrated acceptable inter-rater reliability of MDT in assessing musculoskeletal pain in the spine and extremities using clinical vignettes [22–28]. However, despite the application of MDT in previous case series for assessing and treating participants with chronic pelvic pain, the reliability of MDT specifically in evaluating and classifying CPPS has yet to be investigated [14,15]. Therefore, the first objective was to assess the inter-rater reliability of the MDT assessment in diagnosing CPPS using clinical vignettes derived from real participants. The secondary objectives were to examine the impact of physiotherapist training and participant sex on reliability and to determine the prevalence of the MDT classification categories. We hypothesized that the MDT assessment would be shown to have acceptable inter-rater reliability for classifying CPPS.

Definition of classification subgroups CPPS can be classified into three distinct categories within the MDT system.1) Spinal Derangement classification involves the lasting abolishing or reducing pelvic pain in response to repeated spinal movements. This classification suggests a spinal origin of pelvic pain. 2) Pelvic Floor Contractile Dysfunction classification encompasses pelvic pain consistently triggered by loading and/or stretching of the pelvic floor muscles. This subgroup is associated with pelvic pain originating from pelvic floor muscle dysfunction. 3) MDT OTHER subgroups account for pelvic pain stemming from other sources, such as pelvic girdle structures including the sacroiliac joint and pubic symphysis, as well as nociplastic pain resulting from central sensitization. Assessment method The assessment of participants with CPPS can be challenging due to variations in participants’ comfort levels regarding disclosing urinary and sexual concerns and undergoing physical examinations. Also, direct observation by multiple clinicians simultaneously can be uncomfortable to participants. To address these ethical and observational issues, we utilized clinical vignettes based on real scenarios [29]. Clinical vignettes offer a valid and cost-effective method to evaluate the clinical decision-making and judgment of healthcare professionals in outpatient settings [30]. They provide a standardized approach to presenting cases without requiring direct participant interaction. Evaluator profiles Five clinicians, all physiotherapists with varying levels of training in the MDT, were recruited based on their willingness to participate in the research. Among them, two had lower levels of MDT training, having participated in some courses but not completed any exams. Two were credentialed MDT clinicians, meaning they participated in all five courses and passed an exam. One was an MDT diplomat, which entails being certified and having done additional rigorous training and examinations afterward. All clinicians are qualified to treat pelvic pain and conduct pelvic floor internal assessments. The clinicians, four females and one male, were from the United States and Canada. Table 1 provides detailed demographic information about each clinician. Table 1. | Clinician | 1 | 2 | 3 | 4 | 5 | |---|---|---|---|---|---| | Age | 41 | 26 | 40 | 29 | 38 | | Gender | Female | Female | Male | Female | Female | | Country | Canada | Canada | Canada | Canada | USA | | Years of practice in pelvic health | 15 | 2 | 8 | 5 | 3 | | The proportions of male patients vs. female patients in practice | 90% female | 100% female | 95% male | 95% female | 90% female | | Highest level of MDT training | Credentialed | Part D | Credentialed | Part B | Diplomat | Prior to data collection, Clinician 3, who is credentialed in MDT and has previously written a case series on the use of MDT for male patients with Lower Urinary Tract Symptoms (LUTS) [14] and contributed to the development of MDT pelvic assessment forms, conducted two 90-minute training sessions with the other clinicians. These sessions covered various aspects, including creating clinical vignettes and establishing diagnostic criteria for the MDT pelvic classifications: Spinal Derangement, Pelvic Floor Contractile Dysfunction, and the OTHER subgroups. All clinicians have incorporated MDT principles in classifying and treating CPPS in their practice, such as applying repeated spinal movements to rule out a spinal origin. Pelvic Floor Contractile Dysfunction is adopted from the MDT classification for extremities and is defined as intermittent localized pelvic pain caused by loading the pelvic floor’s contractile tissue via internal manual resisted testing. During the training, each clinician reviewed and discussed 20 practice cases. These sessions were followed by feedback and constructive discussions to ensure all clinicians agreed on the diagnostic criteria for each classification. Data collection Data collection took place at an outpatient physical therapy clinic in Montreal (VActive Centre de Réadaptation and Physiothérapie). Clinicians 1, 2, and 3, who worked together at this clinic, were responsible for participant recruitment and independently creating the clinical vignettes. The study included men and women aged 18 years or older referred for pelvic floor physiotherapy to treat chronic pelvic pain. Participants with specific conditions such as active urological and/or gynecological infections, genital dermatological conditions, current pregnancy, vaginal delivery within the past six months, or pelvic/spinal trauma within the last six months were excluded. Full and informed consent was obtained from all participants prior to using their data for analysis, and ethics was obtained from the local research board. Stage 1: develop clinical vignettes The study utilized the McKenzie Pelvic Pain Assessment Form (see Appendix I and Appendix II), which was approved by the McKenzie Institute International, to develop the clinical vignettes. The blank forms were modified to exclude the participant names and other identifying information and were coded. The collected data included participants’ characteristics (age and sex, detailed history of current symptoms, current and past medical and obstetric history). The assessment involved evaluating posture, range of motion of the lumbar spine and pelvis, neurological examination, internal digital assessment of the pelvic floor musculature (via the vagina or rectum) and observing symptom response to repeated movements of the lumbar spine and contraction of the pelvic floor muscles. The obtained evaluation information was used to create the clinical vignettes. All assessment details, except for the final MDT classification, were included in the vignettes. Additionally, all vignettes were independently reviewed by an MDT clinician to ensure completeness and that any identification of the participant was omitted. Any incomplete or ambiguous information was identified, flagged, and discussed with the clinician who developed the vignette to ensure accuracy. Stage 2: classify clinical vignettes Each of the five clinicians classified the vignettes, but did not classify the ones they developed. To prevent bias, clinicians were not allowed to communicate with each other during the classification process, nor were they allowed to view the classifications provided by other clinicians. Thus, each vignette was independently classified by four different clinicians. The classification of the therapist who developed the vignette was not included in the reliability study. The primary outcome of the study was the classification of clinical vignettes into three categories: 1) Spinal Derangement, 2) Pelvic Floor Contractile Dysfunction, or 3) MDT OTHER subgroups. Statistical analysis To address the primary objective, inter-rater reliability between all clinicians was calculated using the Fleiss kappa statistic with 95% confidence intervals. Cohen’s kappa was used to examine the reliability between pairs of raters. Fleiss kappa statistics were also completed separately for male and female vignettes to determine the impact of sex on reliability. Cohen’s kappa statistic examined the reliability between clinicians with high level of MDT training (n = 3; credentialed and diplomat) and separately for clinicians with lower level of training (n = 2; completed some MDT courses but did not complete exams).A bootstrap procedure with 1000 samples was used to compare Cohen’s kappa values between these MDT training levels and determine 95% confidence intervals around the difference. For this analysis, only 63 vignettes were available since a clinician that created a vignette could not also classify this vignette. Likewise, although there were three clinicians with higher level of training, only two of them would classify each vignette. Kappa values were interpreted based on predefined thresholds: less than 0.40 (poor), 0.41–0.60 (moderate), 0.61–0.80 (good), and 0.81–1.00 (very good). Data obtained during the reliability phase of the study were also utilized to ascertain the prevalence of the two classifications and the OTHER subgroups within the pelvic pain population. The classifications that receive unanimous agreement from all clinicians were used to determine prevalence. To determine the required sample size, a calculation was performed based on estimated prevalence rates of the MDT classifications: Spinal Derangement (0.45), Pelvic Floor Contractile Dysfunction (0.20), and MDT Other subgroups (0.35). These estimates were derived from clinical experience, as no previous research was available in this area. The kappa value was estimated to be 0.80 based on a previous study evaluating MDT reliability in spine disorders [22,31]. Considering four assessors, three classifications, a significance level of p = 0.05, and a lower 95% confidence kappa value of 0.70, a total of 71 participants/vignettes was determined to be necessary. As a precaution, the sample size was increased to 76 in case some vignettes did not meet the standard.

The 76 participants included 40 females and 36 males. Demographic statistics for the participants are provided in Table 2. For the 40 female participants, the median number of pregnancies was one (minimum = 0, maximum = 4), the median number of deliveries was one (minimum = 0, maximum = 5), the median number of vaginal deliveries was one (minimum = 0, maximum = 5), and the median number of Caesarean sections was zero (minimum = 0, maximum = 2). Table 2. | Variable | Participants (n = 76) | | |---|---|---| | Age (y)- Mean (SD) | 42 (14) | | | Symptom Duration (months)- Mean (SD) | 24 (59) | | | Sex- Frequency (%) | Female | 40 (53%) | | Male | 36 (47%) | | | Relationship Status- Frequency (%) | Married | 45 (59%) | | Single | 26 (34%) | | | Divorce | 3 (4%) | | | Widow | 2 (3%) | | | Highest Level of Completed Education- Frequency (%) | Less than high school | 3 (15%) | | Highschool | 32 (42%) | | | University | 41 (54%) | | | Sexually Active- Frequency (%) | Yes | 51 (67%) | | No | 25 (33%) | | | History of Back Pain- Frequency (%) | Yes | 49 (64%) | | No | 27 (36%) | Between all the clinicians, there was good inter-rater reliability (Fleiss kappa = 0.616, 95% CI = 0.598, 0.633) which was statistically significant (p < 0.001). There was 100% agreement among all the clinicians on 62% (47 of 76) of the vignettes. When evaluating pairs of clinicians, there was poor to very good inter-rater reliability (Table 3). The highest agreement was between Clinician 1 and 3 (92.3%), while the lowest agreement was between Clinician 4 and 5 (65.8%).In terms of prevalence, the most common classification was Derangement (57%), followed by the OTHER subgroups (26%) and pelvic floor Contractile Dysfunction (17%). Table 3. | Clinicians Comparison | Cohen Kappa (95% CI) | % Agreement | Numbered of shared vignettes | |---|---|---|---| | Clinician 1 vs 2 | 0.738 (0.525, 0.951) | 86.1 | 36 | | Clinician 1 vs 3 | 0.874 (0.636, 1.111) | 92.3 | 13 | | Clinician 1 vs 4 | 0.573 (0.375, 0.772) | 73.5 | 49 | | Clinician 1 vs 5 | 0.536 (0.320, 0.755) | 73.5 | 49 | | Clinician 2 vs 3 | 0.739 (0.503, 0.975) | 85.2 | 27 | | Clinician 2 vs 4 | 0.670 (0.493, 0.847) | 82.5 | 63 | | Clinician 2 vs 5 | 0.564 (0.363, 0.765) | 77.8 | 63 | | Clinician 3 vs 4 | 0.576 (0.362, 0.789) | 72.5 | 40 | | Clinician 3 vs 5 | 0.839 (0.689, 0.989) | 90.0 | 40 | | Clinician 4 vs 5 | 0.422 (0.242, 0.603) | 65.8 | 76 | CI, confidence interval. Inter-rater reliability was higher when classifying vignettes from female participants (Fleiss kappa = 0.658, 95% CI = 0.634, 0.682) than male participants (Fleiss kappa = 0.546, 95% CI = 0.519, 0.573). Vignettes from male participants were more likely to be classified as Spinal Derangement (63%), followed by OTHER subgroups (26%) and Pelvic Floor Contractile Dysfunction (10%). A similar trend was noted in vignettes from female participants, although there was a decrease in the Spinal Derangement classification and an increase in the Pelvic Floor Contractile Dysfunction classification (Spinal Derangement = 51%, OTHER = 26%; Pelvic Floor Contractile Dysfunction = 24%). Grouped by MDT training levels, clinicians with the highest level of training (credential/diploma) had a moderate agreement (Kappa = 0.587, 95% CI = 0.396, 0.777), while those with a lower level of training had a substantial agreement (Kappa = 0.670, 95% CI = 0.493, 0.847). Using the bootstrap procedures, the mean difference between these groups was −0.083 (95%CI = −0.296, 0.126). Thus, there was no significant difference between clinicians groups based on level of education since the CI interval included 0.

This study represents the first investigation into the reliability of MDT for CPPS. The key findings of this study indicate a good inter-rater reliability among MDT clinicians when utilizing the MDT system to classify pelvic pain syndrome. Up until now, this application of MDT has been unexplored, this study gives a provisional indication that there could be significant implications for the way clinicians analyze and treat CPPS in the future. When using MDT for classifying pelvic pain syndrome, we observed an inter-rater reliability (Fleiss kappa = 0.616) that is comparable to that of the spine (Fleiss kappa = 0.56) [22]. However, it slightly falls below the inter-rater reliability reported for extremity conditions (Fleiss kappa = 0.70–0.90) [23–28]. Previous reliability studies have indicated that more experienced MDT therapists tend to report higher κ values [22,32,33]. The average training level of the five clinicians involved in our study is lower compared to the clinicians in the extremity reliability studies, which may explain the difference. Comparing pairs of clinicians, we find that Clinicians 1, 2, and 3, who were involved in creating the vignettes, demonstrated higher kappa values when compared among themselves, indicating a better understanding and more consistent application of the vignette criteria. For instance, the substantial to almost perfect agreement between Clinician 1 and 3 (Cohen’s kappa = 0.874) and between Clinician 2 and 3 (Cohen’s kappa = 0.739) underscores their strong consistency. In contrast, the kappa values are lower when comparing the vignette creators with the non-creators, such as Clinician 1 vs. 4 (Cohen’s kappa = 0.573) and Clinician 2 vs. 5 (Cohen’s kappa = 0.564), reflecting discrepancies in criteria application. The lowest agreement is observed between the non-creators, Clinician 4 and 5 (Cohen’s kappa = 0.422), suggesting greater variability in their interpretations. Clinicians 1, 2, and 3, who developed the vignettes, had used these forms in their daily practice for a year before data collection began. On the other hand, Clinicians 4 and 5 did not integrate these forms into their routine practice, which likely led to their lower agreement due to their lesser familiarity with the assessment forms. Interestingly, we found that the inter-rater reliability was higher when classifying vignettes from female participants (Fleiss kappa = 0.658, 95% CI = 0.634–0.682) compared to male participants (Fleiss kappa = 0.546, 95% CI = 0.519–0.573). It is worth noting that over 90% of the clients of the four clinicians involved in evaluating the male vignettes were female, with an average proportion of female clients of 93.75%. Clinically, the presentations of pelvic pain in males and females exhibit significant differences. The physical examination procedures and loading strategies for the pelvic floor also vary between the two sexes. Limited clinical experience in treating male pelvic pain patients could potentially impact the interpretation of clinical findings and lead to different conclusions. One advantage of utilizing the MDT system for classifying pelvic pain is that the diagnostic criteria for the three classifications are the same for both male and female patients, and the resulting treatment options are similar. Therefore, the MDT system may offer a better option for pelvic health clinicians to classify pelvic pain, facilitating intra-professional communication and clinical decision-making. In our study sample, the most common classification was Derangement, followed by the OTHER subgroups and Pelvic Floor Contractile Dysfunction. We observed a similar trend among male and female participants, although males were more likely to be classified as Derangement and females as a Pelvic Floor Contractile Dysfunction. This difference can be explained by the fact that the female sex is a risk factor for pelvic floor injuries, such as those occurring during pregnancies, deliveries, and gynecological interventions [34]. In all, two case series have previously described Spinal Derangement in pelvic pain patients, where the treatment of directional preference exercise has been shown to provide rapid and long-lasting relief of symptoms in both the short and long term [14,15]. Therefore, our study further supports the existence of this classification in CPPS. This can be explained by a Spinal Derangement causing referred pain to the pelvis through spinal nerves or directly affecting the innervations of the lower urinary tract, striated sphincter and pelvic floor musculature [35]. Despite the importance of thorough spinal screening in CPPS, the clinical process can be challenging. For instance, imaging studies of the spine often have a high false-positive rate [36]. Incorporating a pelvic classification system that involves repeated spinal movement testing while closely monitoring the symptomatic response could offer a cost-effective and reliable method to rule out the spinal origin of pelvic pain. This approach has been provisionally tested and demonstrated in differentiating extremity pain, where 43.5% of isolated extremity pain was found to have a spinal source [37]. Similarly, hip pain which shares overlapping referral areas with the pelvic floor from the thoracolumbar spine, has been reported to have a spinal origin in as high as 71% of cases [37]. The prevalence of Pelvic Floor Contractile Dysfunction in our sample was 17%, which aligns with previous reports on Contractile Dysfunction in Hip/Groin pain (16.7%) and extremity pain in general (17%) [37]. The pelvic floor has long been recognized as a potential source of pelvic pain; however, the assessment and diagnosis of pelvic floor dysfunction lacks a standardized approach as palpation-based findings lack reliability [16,17]. Significantly, approximately 26% of the participants in our sample were categorized into the OTHER subgroups, which is consistent with previous studies involving spine (25%) and extremity pain patients (36%) [38,39]. The symptoms experienced by these patients did not respond in a lastingly positive way to repeated spinal movements and were not reproduced consistently by loading the pelvic floor. Examples of the classifications included in this grouping are Chronic Pain Syndrome, Peripheral Neuropathy and Mechanically Inconclusive. Some of these patients may have greater drivers of pain and disability, and therefore may benefit from pain education, gradual loading/activity and a multidisciplinary biopsychosocial approach. The major limitation of our study, which used clinical vignettes to assess inter-rater reliability, is its potential inability to fully capture the complexities and variability encountered in real participant interactions [40]. This can lead to an easier diagnosis and potentially inflate the calculated agreement among clinicians [30,41]. Additionally, the fact that the vignettes were created by the study participants themselves likely contributed to an inflated level of agreement. Another significant limitation that is important to highlight is that reliability does not equate to accuracy. A reliable test can consistently produce the same results, even if those results are not correct or valid. Therefore, while our study may demonstrate that clinicians can reliably use the MDT system to classify CPPS, it does not necessarily confirm that the classifications themselves are accurate or valid. To address this limitation, further studies are needed to evaluate the validity of the classifications, ensuring that they accurately represent the underlying conditions and lead to effective treatment strategies. To improve the validity of future studies, it is recommended to incorporate direct observation of real participant encounters in addition to utilizing clinical vignettes. Furthermore, conducting research involving larger sample sizes and diverse populations would enhance the generalizability of the findings. As well, diverse clinician training could have influenced the findings. In the future, conducting the study exclusively with diplomat clinicians would potentially be more reliable. Finally, future studies should analyze the different diagnoses in the OTHER subgroups.

This study represents the first investigation into the inter-rater reliability of the MDT in assessing and classifying CPPS. The findings indicate acceptable inter-rater reliability among trained MDT clinicians when utilizing clinical vignettes. The Spinal Derangement classification emerged as the most commonly observed, followed by the OTHER subgroups and Pelvic Floor Contractile Dysfunction. These results provide provisional evidence supporting the further exploration of MDT in the assessment of chronic pelvic pain and suggest the need for further research in this area. Future studies can build upon these findings to deepen our understanding and refine the use of MDT in the evaluation and classification of CPPS. Supplementary Material Biography Di Wu trained as a medical doctor and completed his residency in Beijing, China. He practiced as an Orthopedic Surgeon for several years before establishing himself in Montreal, Canada, where he attended McGill University and obtained a Master’s degree in physical therapy. This experience enriched his expertise in managing musculoskeletal conditions and provided him with additional perspectives on treating musculoskeletal system disorders. Di developed a strong interest in the link between spinal conditions and pelvic pain syndrome, and he innovatively used Mechanical Diagnosis and Therapy as a screening tool to rule out spinal sources of pelvic pain and dysfunction. He is now a physical therapist and the director of VActive Centre de Réadaptation et de Physiothérapie, where he provides services for a wide range of health conditions, including musculoskeletal disorders and male pelvic-related issues. Combining his strong background in medicine and rehabilitation, Di draws upon a vast body of knowledge to identify and apply the best treatment options for his patients. Funding Statement The research was funded by the Robin McKenzie Endowed Training Grant from the International MDT Research Foundation. Disclosure statement No potential conflict of interest was reported by the author(s). Supplementary material Supplemental data for this article can be accessed online at https://doi.org/10.1080/10669817.2025.2475456.

- [1].Latthe P, Latthe M, Say L, et al. WHO systematic review of prevalence of chronic pelvic pain: a neglected reproductive health morbidity. BMC Public Health. 2006;6(1):1–7. doi: 10.1186/1471-2458-6-177 [DOI] [PMC free article] [PubMed] [Google Scholar] - [2].Klotz SG, Schoen M, Ketels G, et al. Physiotherapy management of patients with chronic pelvic pain (CPP): a systematic review. Physiother Theory Pract. 2019;35(6):516–532. doi: 10.1080/09593985.2018.1455251 [DOI] [PubMed] [Google Scholar] - [3].Schaeffer AJ. Epidemiology and evaluation of chronic pelvic pain syndrome in men. Int J Antimicrob Agents. 2008;31:108–111. doi: 10.1016/j.ijantimicag.2007.08.027 [DOI] [PubMed] [Google Scholar] - [4].Fall M, Baranowski AP, Elneil S, et al. EAU guidelines on chronic pelvic pain. Eur Urol. 2010;57(1):35–48. doi: 10.1016/j.eururo.2009.08.020 [DOI] [PubMed] [Google Scholar] - [5].Clemens JQ, Markossian T, Calhoun EA. Comparison of economic impact of chronic prostatitis/chronic pelvic pain syndrome and interstitial cystitis/painful bladder syndrome. Urology. 2009;73(4):743–746. doi: 10.1016/j.urology.2008.11.007 [DOI] [PMC free article] [PubMed] [Google Scholar] - [6].Lai HH, Jemielita T, Sutcliffe S, et al. Characterization of whole body pain in urological chronic pelvic pain syndrome at baseline: a MAPP research network study. J Urol. 2017;198(3):622–631. doi: 10.1016/j.juro.2017.03.132 [DOI] [PMC free article] [PubMed] [Google Scholar] - [7].Shoskes DA, Nickel JC. Classification and treatment of men with chronic prostatitis/chronic pelvic pain syndrome using the UPOINT system. World J Urol. 2013;31(4):755–760. doi: 10.1007/s00345-013-1075-6 [DOI] [PubMed] [Google Scholar] - [8].Clemens JQ, Mullins C, Ackerman AL, et al. Urologic chronic pelvic pain syndrome: insights from the MAPP research network. Nat Rev Urol. 2019;16(3):187–200. doi: 10.1038/s41585-018-0135-5 [DOI] [PMC free article] [PubMed] [Google Scholar] - [9].Patil S, Daniel G, Engle JG, et al. Urological chronic pelvic pain syndrome improves when underlying neuromuscular dysfunction is addressed in an outpatient, multimodal treatment protocol. J Men’s Health. 2022;18(2):50. [Google Scholar] - [10].Natarajan J, Ahmed T, Patil S, et al. Pain and functionality improved when underlying neuromuscular dysfunction addressed in chronic pelvic pain patients. Neurourol Urodyn. 2021;40(6):1609–1615. doi: 10.1002/nau.24726 [DOI] [PubMed] [Google Scholar] - [11].Patil S, Daniel G, Vyas R, et al. Neuromuscular treatment approach for women with chronic pelvic pain syndrome improving pelvic pain and functionality. Neurourol Urodyn. 2022;41(1):220–228. doi: 10.1002/nau.24799 [DOI] [PubMed] [Google Scholar] - [12].Rosenbaum TY, Owens A. The role of pelvic floor physical therapy in the treatment of pelvic and genital pain-related sexual dysfunction (vol 5, pg 513, 2008). J Sex Med. 2008;5(3):1513–1513. doi: 10.1111/j.1743-6109.2007.00761.x [DOI] [PubMed] [Google Scholar] - [13].Anderson RU, Wise D, Sawyer T, et al. Sexual dysfunction in men with chronic prostatitis/chronic pelvic pain syndrome: improvement after trigger point release and paradoxical relaxation training. J Urol. 2006;176(4):1534–1539. doi: 10.1016/j.juro.2006.06.010 [DOI] [PubMed] [Google Scholar] - [14].Wu D, Rosedale R. The use of mechanical diagnosis and therapy (MDT) in patients with lower urinary tract symptoms (LUTS): case series. Physiother Theory Pract. 2019;35(4):383–391. doi: 10.1080/09593985.2018.1443359 [DOI] [PubMed] [Google Scholar] - [15].Hughes C, May S. A directional preference approach for chronic pelvic pain, bladder dysfunction and concurrent musculoskeletal symptoms: a case series. J Man Manipulative Ther. 2020;28(3):170–180. doi: 10.1080/10669817.2019.1668994 [DOI] [PMC free article] [PubMed] [Google Scholar] - [16].Meister MR, Shivakumar N, et al. Physical examination techniques for the assessment of pelvic floor myofascial pain: a systematic review. Am J Obstet Gynecol. 2018;219(5):497–e1. doi: 10.1016/j.ajog.2018.06.014 [DOI] [PMC free article] [PubMed] [Google Scholar] - [17].Notenboom‐Nas FJ, Knol‐de Vries GE, Beijer L, et al. Exploring pelvic floor muscle function in men with and without pelvic floor symptoms: a population‐based study. Neurourol Urodyn. 2022;41(8):1739–1748. doi: 10.1002/nau.24996 [DOI] [PMC free article] [PubMed] [Google Scholar] - [18].Frawley H, Shelly B, Morin M, et al. An International Continence Society (ICS) report on the terminology for pelvic floor muscle assessment. Neurourol Urodyn. 2021;40(5):1217–1260. doi: 10.1002/nau.24658 [DOI] [PubMed] [Google Scholar] - [19].Davies C, Nitz AJ, Mattacola CG, et al. Practice patterns when treating patients with low back pain: a survey of physical therapists. Physiother Theory Pract. 2014;30(6):399–408. doi: 10.3109/09593985.2013.877547 [DOI] [PubMed] [Google Scholar] - [20].Liddle SD, Baxter GD, Gracey JH. Physiotherapists’ use of advice and exercise for the management of chronic low back pain: a national survey. Man Ther. 2009;14(2):189–196. doi: 10.1016/j.math.2008.01.012 [DOI] [PubMed] [Google Scholar] - [21].Aytona MC, Dudley K. Rapid resolution of chronic shoulder pain classified as derangement using the McKenzie method: a case series. J Man Manipulative Ther. 2013;21(4):207–212. doi: 10.1179/2042618613Y.0000000034 [DOI] [PMC free article] [PubMed] [Google Scholar] - [22].Clare HA, Adams R, Maher CG. Reliability of the McKenzie spinal pain classification using patient assessment forms. Physiotherapy. 2004;90(3):114–119. doi: 10.1016/j.physio.2004.05.001 [DOI] [Google Scholar] - [23].May S, Ross J. The McKenzie classification system in the extremities: a reliability study using McKenzie assessment forms and experienced clinicians. J Manipulative Physiol Ther. 2009;32(7):556–563. doi: 10.1016/j.jmpt.2009.08.007 [DOI] [PubMed] [Google Scholar] - [24].Takasaki H, Okuyama K, Rosedale R. Inter-examiner classification reliability of mechanical diagnosis and therapy for extremity problems–systematic review. Musculoskeletal Sci Pract. 2017;27:78–84. doi: 10.1016/j.msksp.2016.12.016 [DOI] [PubMed] [Google Scholar] - [25].Takasaki H, Iwasada Y, May S. Attitude towards the use of mechanical diagnosis and therapy and reliability of classification extremity problems by credentialed therapists. J Chiropr Med. 2015;14(1):32–38. doi: 10.1016/j.jcm.2014.12.002 [DOI] [PMC free article] [PubMed] [Google Scholar] - [26].Kelly E, May S, Ross J. The reliability of the McKenzie classification system using extremity McKenzie assessment forms. Int J Mech Diagn Ther. 2008;3(3):3–6. [Google Scholar] - [27].Abady AH, Rosedale R, Overend TJ, et al. Inter-examiner reliability of diplomats in the mechanical diagnosis and therapy system in assessing patients with shoulder pain. J Man Manipulative Ther. 2014;22(4):199–205. [DOI] [PMC free article] [PubMed] [Google Scholar] - [28].Willis S, Rosedale R, Rastogi R, et al. Inter-rater reliability of the McKenzie system of mechanical diagnosis and therapy in the examination of the knee. J Man Manipulative Ther. 2017;25(2):83–90. doi: 10.1080/10669817.2016.1229396 [DOI] [PMC free article] [PubMed] [Google Scholar] - [29].Gould D. Using vignettes to collect data for nursing research studies: how valid are the findings? J Clin Nurs. 1996;5(4):207–212. doi: 10.1111/j.1365-2702.1996.tb00253.x [DOI] [PubMed] [Google Scholar] - [30].Peabody JW, Luck J, Glassman P, et al. Comparison of vignettes, standardized patients, and chart abstraction: a prospective validation study of 3 methods for measuring quality. JAMA. 2000;283(13):1715–1722. doi: 10.1001/jama.283.13.1715 [DOI] [PubMed] [Google Scholar] - [31].Rotondi MA, Donner A. A confidence interval approach to sample size estimation for interobserver agreement studies with multiple raters and outcomes. J Clin Epidemiol. 2012;65(7):778–784. doi: 10.1016/j.jclinepi.2011.10.019 [DOI] [PubMed] [Google Scholar] - [32].Kilpikoski S, Airaksinen O, Kankaanpää M, et al. Interexaminer reliability of low back pain assessment using the McKenzie method. Spine (Phila Pa 1976). 2002;27(8):E207–E214. doi: 10.1097/00007632-200204150-00016 [DOI] [PubMed] [Google Scholar] - [33].Razmjou H, Kramer JF, Yamada R. Intertester reliability of the McKenzie evaluation in assessing patients with mechanical low back pain. J Orthop Sports Phys Ther. 2000;30(7):368–389. doi: 10.2519/jospt.2000.30.7.368 [DOI] [PubMed] [Google Scholar] - [34].Hallock JL, Handa VL. The epidemiology of pelvic floor disorders and childbirth: an update. Obstet Gynecol Clin North Am. 2016;43(1):1–13. doi: 10.1016/j.ogc.2015.10.008 [DOI] [PMC free article] [PubMed] [Google Scholar] - [35].Siracusa G, Sparacino A, Lentini VL. Neurogenic bladder and disc disease: a brief review. Curr Med Res Opin. 2013;29(8):1025–1031. doi: 10.1185/03007995.2013.807788 [DOI] [PubMed] [Google Scholar] - [36].Wnuk NM, Alkasab TK, Rosenthal DI. Magnetic resonance imaging of the lumbar spine: determining clinical impact and potential harm from overuse. Spine J. 2018;18(9):1653–1658. doi: 10.1016/j.spinee.2018.04.005 [DOI] [PubMed] [Google Scholar] - [37].Rosedale R, Rastogi R, Kidd J, et al. A study exploring the prevalence of Extremity Pain of Spinal Source (EXPOSS). J Man Manipulative Ther. 2020;28(4):222–230. doi: 10.1080/10669817.2019.1661706 [DOI] [PMC free article] [PubMed] [Google Scholar] - [38].May SJ, Rosedale R. A survey of the McKenzie classification system in the extremities: prevalence of mechanical syndromes and preferred loading strategies. Phys Ther. 2012;92(9):1175–1186. doi: 10.2522/ptj.20110371 [DOI] [PubMed] [Google Scholar] - [39].May S, Rosedale R. An international survey of the comprehensiveness of the McKenzie classification system and the proportions of classifications and directional preferences in patients with spinal pain. Musculoskeletal Sci Pract. 2019;39:10–15. doi: 10.1016/j.msksp.2018.06.006 [DOI] [PubMed] [Google Scholar] - [40].Evans SC, Roberts MC, Keeley JW, et al. Vignette methodologies for studying clinicians’ decision-making: validity, utility, and application in ICD-11 field studies. Int J Clin Health Phychol. 2015;15(2):160–170. doi: 10.1016/j.ijchp.2014.12.001 [DOI] [PMC free article] [PubMed] [Google Scholar] - [41].Werneke MW, Hart DL, Deutscher D, et al. Clinician’s ability to identify neck and low back interventions: an inter-rater chance-corrected agreement pilot study. J Man Manipulative Ther. 2011;19(3):172–181. doi: 10.1179/2042618611Y.0000000001 [DOI] [PMC free article] [PubMed] [Google Scholar] Associated Data This section collects any data citations, data availability statements, or supplementary materials included in this article.