The majority of clinical trials assessing mobilization and manipulation for neck pain lack a pragmatic approach: a systematic review of 174 trials

ABSTRACT

Background

Disorders of the cervical spine are some of the costliest musculoskeletal conditions to manage globally. Joint mobilization and manipulation have been shown to be an effective treatment for neck pain. However, the generalizability and clinical translation depends on the nature of the trial designs that inform its use. The extent to which randomized control trials (RCTs) assessing manual therapy treatments for cervical spine disorders fall on the efficacy (explanatory) -effectiveness (pragmatic) spectrum often informs how the findings are translated into clinical practice.

Objective

The aim of this systematic review was to determine where RCTs of manual therapy for neck disorders fall on the efficacy-effectiveness spectrum.

Methods

A search of three electronic databases including PubMed, CINAHL, and CENTRAL were completed for trials published from inception to May 2023. RCTs in which joint mobilization or manipulation were used to treat cervical spine disorders were assessed on the effectiveness-efficacy spectrum using the Rating of Included Trials on the Efficacy-Effectiveness Spectrum (RITES) tool and risk of bias using the Revised Cochrane Risk of Bias tool.

Results

A total of 174 trials met eligibility. RITES domain two trial setting (71.3% vs 16.1%), domain three flexibility of intervention(s) (62.1% vs 23%), and domain four clinical relevance of experimental and comparison intervention(s) (51.7% vs 29.3%) all favored efficacy over effectiveness. Domain one participant characteristic(s) had a slightly greater emphasis on effectiveness compared to efficacy (36.8% vs 44.8%). Most studies (96%) had at least some risk of bias.

Conclusion

Over half of the RCTs assessing the treatment effect of joint mobilization and manipulation for neck pain favor efficacy (explanatory) over effectiveness (pragmatic) designs. Future RCTs on this topic should consider a greater emphasis on pragmatic trial design components in order to better reflect real-world translation to clinical practice.

Introduction

Neck pain is one of the most common and costly musculoskeletal disorders globally, alongside low back pain (LBP), resulting in one of the highest healthcare expenditures for musculoskeletal disorders in the United States [1–5]. Although no single intervention has been shown to be superior for neck pain, manual therapy including joint mobilization and manipulation has been shown to improve neck pain [6–12]. However, the applicability of manual therapy interventions used in clinical trials can vary based on overall study design, making it challenging to determine what will work best in routine clinical practice. This variability can create confusion and challenges when attempting to replicate manual therapy interventions in clinical settings. Many randomized controlled trials (RCTs) require specific inclusion/exclusion criteria, such as female-only patients with a narrow age range [13], and use treatment approaches that may appear less relevant for real-world care settings, such as a single session joint manipulation or mobilization [14], which could be considered a sub-clinical dose in many settings [15,16]. This defined criteria can create challenges with knowledge translation when attempting to generalize findings to a broader patient population [17,18].

Clinical trial designs vary in their goals to include explanatory (e.g. efficacy) and pragmatic (e.g. effectiveness) designs. Explanatory trials emphasizing efficacy aim to explore the benefits of an intervention under ideal and highly controlled situations [9–11]. For example, Vieira-Pellenz et al. [19] focused on the explanatory factors by comparing the short-term effects of lumbar manipulation to sham manipulation. The study included a homogenous male patient population, the intervention was performed by one clinician, it implemented a single session with an immediate follow-up assessment, and there was no flexibility in the intervention delivery [19]. Although this design typically minimizes threats to internal validity, the generalizability is not ideal. In contrast, an effectiveness approach would favor external validity [20–23]. The outcomes of these interventions are examined under circumstances that more closely approximate clinical practice, including less standardized treatment protocols applied to more heterogeneous patient populations, and by a larger number of clinicians more representative of routine clinical care [20,24]. In one study, Hoving et al. [25] compared the effectiveness of manual therapy, physical therapy, and continued care by the general practitioner for patients with mechanical neck pain. This study had a heterogeneous patient population, included a long term follow-up of one year, implemented individualized and flexible interventions that allowed for tailored clinical decision making, and used multiple treating clinicians [25]. The reality is that trials in general with these designs are not commonly published, reported to be less than 2% of total RCTs based on MEDLINE searches of title and abstracts in 2010 [23]. Most studies fall somewhere on the spectrum of effectiveness (pragmatic) versus efficacy (explanatory) due to the design of the study [21]. Study designs that are more pragmatic in nature may be more useful for clinicians in that they lend themselves to applicability in a real-world setting while also guiding clinical care and changing clinical practice [26]. Clinical trials often emphasize either internal or external validity in their design; however, many factors such as the patient population, the clinician’s background, the location of treatment, and the intervention strategy all may play a role in determining where on the efficacy-effectiveness spectrum the study design falls and how it can be generalized to clinical practice [9–14].

There is currently a limited understanding of where trial designs lie on the efficacy-effectiveness spectrum for any form of neck pain [21,27,28]. A recent scoping review investigated the reporting of manual therapy interventions in clinical trials for neck pain, but only assessed intervention delivery and not the overall level of efficacy or effectiveness of the study designs [29]. Another systematic review investigated the impact that pragmatic or explanatory interventions had on neck and LBP when comparing joint mobilization versus manipulation; however, this study again only examined the intervention component and did not assess study design aspects such as trial settings, expertise and background of clinicians, and participant characteristics [16]. A more recent systematic review assessed trial designs for manual therapy and LBP as it relates to efficacy and effectiveness [15], but is currently the only study assessing this for any musculoskeletal condition. Given the lack of assessment of pragmatism in trials for patients with neck pain and the relevance for clinical decision making, the primary objective of this systematic review was to assess manual therapy trials for neck pain using the Rating of Included Trials on the Efficacy-Effectiveness Spectrum (RITES) tool to determine where these trial designs fall on the efficacy-effectiveness spectrum. A secondary objective was to determine if patterns of trial design domains (efficacy vs effectiveness) were more likely to be associated with a treatment effect.

Methods

This systematic review was reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [30] and registered a priori (PROSPERO registration number CRD42023425928).

Search strategy

A search strategy of three databases included PubMed, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and CENTRAL (Cochrane Central Register of Controlled Trials) for studies published from inception to May 2023. The search used All Map Terms to Subject Headings, Medical Subject Headings (MeSH) terms, keywords related to neck pain, joint mobilization/manipulation, and the search term including RCTs. Our search strategy included electronic searching of databases for RCTs for individuals who received joint mobilization or manipulation used to treat neck pain and cervical related disorders (e.g. cervicogenic dizziness, cervical radiculopathy, and cervicogenic headaches). The first search used MeSH terms and keywords related to the cervical spine and neck pain in PubMed. The second search used MeSH terms and keywords related to manipulation and mobilization, and the third search used a combination of MeSH terms and keywords for RCTs. The three main search strategies were combined with the Boolean operator AND and OR to identify specific studies relevant to our research question with details provided in Appendix A. Search strategies were modified and adapted based on the requirements of each specific database.

Study selection criteria

We defined manual therapy, for the purpose of this review, as joint mobilization or manipulation in order to control heterogeneity due to the broad range of approaches that can fall under the label of manual therapy [31]. Any RCT where joint mobilization or manipulation was used to treat cervical pain was included in the review. Joint mobilization was defined as a skilled manual therapy intervention applied to a joint at varying speeds and amplitudes using accessory motion in the spine for therapeutic purposes [32]. Joint manipulation was defined as a high-velocity, low-amplitude technique performed at the pathological limit of the joint [32]. Adjunct interventions (e.g. acupuncture, massage, soft tissue mobilization, instrument-assisted soft tissue, mechanically-assisted manipulation), exercise therapy, and other interventions such as modalities, education, or advice were included as long as joint mobilization and manipulation were used and assessing the treatment effect of manual therapy was the primary objective of the research. This also included any placebo or true control group as the comparison arm of the study.

Additionally, we included studies if they: (1) were written in English, and (2) studied adults aged 18+ . We excluded trials if: (1) they focused on non-musculoskeletal related disorders (e.g. migraines and tension-type headaches) in the absence of neck pain or on post-surgical care related to neck pain, (2) the study did not focus on assessing treatment effect for neck disorders, (3) they were not peer reviewed, (4) manual therapy was not the primary focus of the study, (5) there was not enough information in the study to determine inclusion, (6) the full-text was unavailable (e.g. not available in English, protocol or abstract only), (7) subjects were treated for disorders other than the neck, (8) the study was a secondary analysis from an original study, (9) if the sample also included non-adult participants or, (10) the manual therapy assessed did not specifically include joint mobilization/manipulation.

Data management

Covidence software (Veritas Health Innovation Ltg, Melbourne, Australia) was used for all data management [33]. Title, abstracts, and full-texts were uploaded to Covidence where duplicates were removed. Two independent reviewers (KC, MS) performed the title and abstract screening in Covidence to determine eligibility for full-text reviews. Following title and abstract screening, the same two reviewers individually screened the full-text of the included studies for final eligibility. All discrepancies were reconciled by the two reviewers.

Data extraction

Details of the studies including title, year of publication, country of origin, primary author, total sample size, sample size per treatment group, and patient demographics with mean (standard deviation) or proportion were collected within Covidence from each included study. Definitions of manual therapy as defined within the trial, types of neck pain/disorders, and the follow-up time points of the trial were also collected. Information needed for the assessment of the RITES tool and risk of bias was also extracted for each included trial.

Assessment of trial design efficacy-effectiveness spectrum

The RITES tool was used to assess where each trial fell on the efficacy-effectiveness spectrum. This tool is currently underused in assessing the spectrum of trials investigating manual therapy for musculoskeletal conditions [13]. The RITES tool was developed based on categories within the Pragmatic Explanatory Continuum Indicator Summary (PRECIS) tool [34], used to help design trials, and is scored on a 5-point Likert scale within four domains that include participant characteristics, trial setting, flexibility of interventions, and clinical relevance of experimental and comparison interventions [21]. Scoring is completed as one to two being more explanatory, three showing a balance between explanatory and pragmatic, four to five being more pragmatic, and not applicable (N/A) where information was not available [21]. The RITES tool is used to determine the level of efficacy and effectiveness in each study, which was the primary objective of the review [15]. In-depth descriptors for efficacy and effectiveness adapted from Wieland et al. [21] and Maddox et al. [15] are provided in Table 1.

Table 1.

Ratings of included trials on the efficacy-effectiveness spectrum tool domains and descriptors.

	Emphasis on Efficacy	Emphasis on Effectiveness
Domain	Description	Description
Participant characteristics	Participants different than those seen in usual care Restrictive inclusion and exclusion criteria Recruitment process different than what is seen in usual care Homogenous patient population	Similar patients to those likely to receive intervention in usual care Heterogeneous patient population Recruitment consistent with usual care Diverse with parameters that reflect adherence
Trial setting	Single center Specialized/academic setting Additional training or certifications Only one individual providing intervention	Multiple settings Conducted within clinical settings Variety of experience and certifications More than one individual providing intervention
Flexibility of intervention(s)	Less flexible with a strict protocol Other co-interventions discouraged	Interventions performed based on examination findings Minimal-to-no controls over other interventions Advice and education provided with intervention
Clinical relevance of experimental and comparison intervention(s)	Interventions not typical of usual care Immediate follow-up designs Contains a placebo/control group Ineffective interventions performed	Intervention considered best practice Study duration and follow-up typical of usual care Treatment groups optimal for each group

Based on a 5-point Likert scale, each domain rated as follows: 1 = strong emphasis on efficacy, 2 = rather strong emphasis on efficacy, 3 = balanced emphasis on both efficacy and effectiveness, 4 = rather strong emphasis on effectiveness, 5 = strong emphasis on effectiveness, or N/A = information not available. Table adapted from Wieland et al. [21] and Maddox et al. [15]

Risk of bias

Risk of bias for each trial was analyzed by two reviewers (KC, MS) using the Cochrane Collaboration of Risk-of-Bias Tool for Randomized Trials (RoB 2) [35]. The RoB 2 tool assesses bias in five domains including randomization process, deviations from the intended interventions, missing outcome data, measurement of the outcome, and selection of the reported result [35]. A score of low, high, or some concerns was assigned for each domain [36].

Data synthesis and analysis

To ensure consistency in the data extraction process, the two independent reviewers (KC, MS) planned to extract data independently for iterations of 20 studies until a minimum agreement of 80% was reached. The level of agreement was initially 84.4% within the first 20 studies for data items extracted. An additional nine studies were reviewed for additional consistency with data extraction, RITES scores, and risk of bias scores. The remaining studies were divided, and data was then extracted independently by the two reviewers. After the four domains of the RITES tool were scored for each trial, results were reported descriptively by domain. For each RITES domain, the proportion of all trials that focused more on efficacy (explanatory) compared to effectiveness (pragmatic) was determined, as well as those that were balanced between efficacy and effectiveness.

Each reviewer completed the RoB 2 for all studies individually where a consensus was made on each item afterward. After RoB judgments were determined for each trial, count and percentage data were calculated based on the number of trials having low, high, or some concerns for risk of bias.

A logistic regression was used to model the relationship between each of the four efficacy-effectiveness spectrum domains in RITES score (one through five) and the study treatment effect (positive versus null trial). For the model, a score of one or two was considered a study with higher efficacy, a score of three was a neutral study, and a score of four or five was a study with higher effectiveness. Each of the four domains was assessed in a separate model. All statistical analyses were performed using IBM SPSS Statistics (Version 28; Chicago, IL) [37].

Results

The initial search identified 4063 studies. A total of 1266 duplicates were removed resulting in 2797 studies for title and abstract screening. After title and abstract screening, 2412 studies were excluded followed by another 211 after full-text review resulting in a final total of 174 [7,8,13,14,25,38–206]. Figure 1 provides reasons for exclusion during full-text screening. There was moderate agreement between reviewers for title and abstract screening (k = .52) and substantial agreement for full-text review (k = .66).

Figure 1.

Preferred reporting items for systematic reviews and meta-analyses (PRISMA) flow diagram.

A total of 117 (67.2%) studies in this review investigated nonspecific neck pain. Additionally, we identified 15 (8.6%) studies specific to cervical radiculopathy, 19 (10.9%) to cervicogenic headaches, 8 (4.6%) to cervicogenic dizziness with neck pain, 4 (2.3%) to whiplash associated disorder, and 11 (6.6%) as other including neck strain, cervical osteoarthritis/spondylosis, etc. Spain (20.1%, n = 35), United States (16.7%, n = 29), and Australia (7.5%, n = 13) were the top three countries publishing manual therapy trials for neck pain. Regarding follow-up within each trial, 20.7% (n = 36) of trials assessed outcomes immediately post treatment, 30.9% (n = 54) assessed them within one month, 20.7% (n = 36) assessed them after one month and up to three months, 8.6% (n = 15) assessed them from three to six months, and 11.6% (n = 20) assessed them beyond six months. A total of 7.5% (n = 13) of trials did not specify length of follow-up.

RITES scores

A significant proportion of studies had an emphasis on efficacy (scores of one or two) over effectiveness (scores of four or five) for the four domains of the RITES tool (Figure 2). Participant characteristics (RITES domain one) was the only domain with a slightly greater emphasis on effectiveness compared to efficacy. Individual RITES scores can be found in Figure 4.

Figure 2.

RITES scoring of included trails (by percentage and count). Abbreviation: RITES, ratings of included trials on the efficacy-effectiveness spectrum.

Figure 4.

RITES scores for trails included in systematic review.

Participant characteristics (RITES domain one)

For this domain, we identified 19 trials (10.9%) with strong efficacy, 45 (25.9%) with rather strong efficacy, 31 (17.8%) were balanced between the two, 57 (32.8%) with rather strong effectiveness, and 21 (12.1%) with a strong emphasis on effectiveness. A total of 64 (36.8%) trials had strong or rather strong emphasis on efficacy, whereas 78 (44.8%) had strong or rather strong emphasis on effectiveness. One study (0.6%) out of the 174 was judged as N/A as there was not enough information within the study to make a determination about this domain.

Trial setting (RITES domain two)

For this domain, we identified 84 trials (48.3%) with strong efficacy, 40 (23%) with rather strong efficacy, 13 (7.5%) were balanced between efficacy and effectiveness, 7 (4%) with rather strong effectiveness, and 21 (12.1%) with an emphasis on strong effectiveness. A total of 124 (71.3%) had strong or rather strong emphasis on efficacy, whereas 28 (16.1%) had strong or rather strong emphasis on effectiveness. Nine studies (5.2%) out of the 174 were judged as N/A as there was not enough information within the study to make a determination about this domain.

Flexibility of interventions (RITES domain three)

We identified 72 trials (41.4%) with strong efficacy, 36 (20.7%) with rather strong efficacy, 26 (14.9%) were balanced, 17 (9.8%) with rather strong effectiveness, and 23 (13.2%) with strong effectiveness. A total of 108 (62.1%) had strong or rather strong emphasis on efficacy, whereas 40 (23%) had strong or rather strong emphasis on effectiveness. No studies in this domain were judged as N/A.

Clinical relevance of experimental and comparison intervention(s) (RITES domain four)

For this domain, we identified a total of 55 (31.6%) trials with strong efficacy, 35 (20.1%) with rather strong efficacy, 33 (19%) were balanced, 27 (15.5%) with rather strong effectiveness, and 24 (13.8%) with strong effectiveness. A total of 90 (51.7%) had strong or rather strong emphasis on efficacy, whereas 51 (29.3%) had strong or rather strong emphasis on effectiveness. No studies in this domain were judged as N/A.

Assessment of RITES scores on outcomes of trial

Most RITES trial domains that favored effectiveness were more likely to be null trials, for trial setting (OR = 0.38, 95% CI 0.17–0.88; p = .02), flexibility of interventions (OR = 0.36, 95% CI 0.17–0.77; p = .01), and clinical relevance of experimental and comparison interventions (OR = 0.39, 95% CI 0.18–0.78; p = .01). The only domain where there was no significant difference in trial outcome was the domain of participants (OR = 1.46, 95% CI 0.74–2.89; p = .28).

Risk of bias (RoB 2)

The majority of trials had at least some risk or high risk of bias (Figure 3). The most common reasons were concerns identified with the patient using patient-reported outcomes (e.g. Neck Disability Index) as the primary outcome, handling of missing data, and not registering the trial a priori. A total of 136 (78.2%) trials were judged as having some concerns of bias, 31 (17.8%) demonstrated an overall high risk of bias, and only 7 (4%) demonstrated a low risk of bias. See Appendix B for individual risk of bias scores for each trial. All risk of bias figures and appendixes were created using an online risk of bias visualization tool called ROBVIS [207].

Figure 3.

Aggregate risk of bias summary across all studies in this review.

Discussion

This review, to our knowledge, is the first to specifically evaluate the designs of clinical trials assessing manual therapy treatment for neck pain on the efficacy-effectiveness spectrum. Three out of the four RITES domains favored efficacy over effectiveness for the RCTs included within this review. Within the domain of participant characteristics, clinical trials marginally favored effectiveness over efficacy, while the remaining three domains, including trial setting, flexibility of intervention(s), and clinical relevance of experimental and comparison intervention(s), favored efficacy, consistent with our hypothesis that the majority of RCTs would have less pragmatic designs. These findings are consistent with studies assessing this same question in trials for low back pain [15].

For the trial setting domain, some examples of explanatory characteristics included the RCT being conducted within university settings, having only one treatment provider or using specialized provider(s) with advanced post-professional training, and including only one clinical setting. In one study, a fully registered trained osteopathic practitioner with ten years of clinical and academic experience provided the treatment conducted within a university setting [173]. Common reasons trials were explanatory in the domain of flexibility of intervention(s) include examples of strict criteria of intervention(s) set forth within the methods (e.g. performing three sets of one-minute lateral glide), no ability to modify location or intervention(s) based on patient findings, and participants being prohibited on other co-interventions such as medication and exercise. Saavedra-Hernandez et al. [169] used an intervention group where a mid-cervical spine manipulation technique was directed at C3 in supine and a C7-T1 manipulation technique was performed in prone for each patient regardless of presentation. For the domain of clinical relevance of experimental and comparison intervention(s), the most common examples of how RCTs favored explanatory designs were due to not performing a clinically relevant or current best practice treatment and the study duration being shorter than the minimum length of treatment in usual care (e.g. immediate follow-up, one treatment session). For example, Yung et al. [195] had a short-term follow-up of two days following intervention using only non-thrust mobilizations without other adjunct treatment or education provided.

The discussion of efficacy (explanatory) and effectiveness (pragmatic) designs in clinical trials is not a new topic, with literature dating as far back as the late 1960s [208]. Maddox et al. [15] was the first to assess the effectiveness versus efficacy nature of studies for joint mobilization and manipulation in the treatment of generalized LBP, finding over half the trial designs favoring efficacy consistent with this study’s findings. We included trials of different health professionals beyond physical therapists treating neck pain with manual therapy for greater generalizability as we hypothesized a lower number of studies of neck trials compared to LBP [15]. No other studies have assessed the efficacy-effectiveness spectrum of manual therapy trials for other body regions beyond the lumbar spine.

Our findings suggest more manual therapy trial designs with effectiveness (pragmatic) approaches are needed to to better assist with knowledge translation into real-world clinical settings. However, development of trial designs with this in mind can be challenging. One way to assist with development of pragmatic trials prospectively is the Pragmatic-Explanatory Continuum Indicator Summary (PRECIS-2) tool. This tool can assist researchers in prospectively designing RCTs with a pragmatic emphasis [34]. The PRECIS-2 tool contains nine domains to consider when designing a specific study including eligibility, recruitment, setting, organization, delivery and adherence to interventions, follow-up, primary analysis, and primary outcome [21,34]. Using these nine domains, researchers can be more explicit with their trial design development to best fit their primary outcome focusing on a effectiveness (pragmatic) approach [34].

We found that if a trial design had a greater focus on effectiveness in the RITES domains of trial setting, flexibility of intervention(s), or clinical relevance of experimental and comparison intervention(s), it had decreased odds of showing a treatment effect. However, we recommend caution when interpreting these findings. Many of the studies within this systematic review had great variability in what was included in each comparison group. Comparison groups for studies considered to favor effectiveness often included manipulation and/or mobilization for treatment of neck pain, as well as other clinically relevant treatment interventions. For example, Karas et al. [108] compared flexion-biased versus extension-biased thoracic manipulation with pragmatic exercise prescription by each PT finding no differences between groups. Further research is necessary before any definitive conclusions are made.

There are some limitations in this review. Several common cervical disorders were poorly represented (e.g. whiplash associated disorder, cervicogenic dizziness, and cervical radiculopathy), which was due to few trials assessing the effect of manual therapy for these conditions. Second, while limiting the manual therapy interventions to only joint mobilization and manipulation techniques, some techniques that may not traditionally be known in some settings as joint mobilization and manipulation, including Chuna manual therapy, bone setting, Mulligan mobilization, instrument-assisted manual manipulation (e.g. Activator), and naprapathic manual therapy, were included. These treatment interventions all met the criteria established to define manual therapy techniques as those consisting of joint mobilization and manipulation [31,32]. Lastly, no meta-analysis was conducted as that was not the intent of this review, and therefore treatment effects of manual therapy for neck pain could not be determined.

Conclusion

Over half (55.5%) of the clinical trials assessing joint mobilization and manipulation for neck pain favored efficacy (explanatory) over effectiveness (pragmatic) trial designs. Trials designed to have a greater focus on effectiveness (pragmatic) were less likely to find a treatment effect. Additional trials are needed with a greater focus on effectiveness designs to better facilitate generalizability and knowledge translation. Researchers should also considers including the use of multiple centers to conduct trials, implementation beyond university settings, using a variety of treating clinicians with various experience and specialties, properly explaining the influence of sample heterogeneity on the conclusions that can be made when presenting results of the trial, not restricting groups from other real world co-treatments they may be receiving, allowing clinicians to deliver interventions similar to how they would be delivered in real world settings, and extending time of follow-up beyond the immediate or short-term. Although we found that three of four domains that favored effectiveness over efficacy had decreased odds of showing a treatment effect, the results should be interpreted cautiously. Trials are designed to ask unique questions. The nature of those questions could be explored in more depth when designing trials, with tools like the PRECIS-2 checklist [34], based on the desired intent and impact of the study question.

Biographies

Kyle Cottone PT, DPT, OCS, FAAOMPT is an assistant professor and core faculty in the Bradley University DPT program in Peoria, IL. He is a Board-Certified Orthopaedic Clinical Specialist through the American Physical Therapy Association and Fellow of the American Academy of Orthopaedic Manual Physical Therapy.

Matthew Schumacher PT, DPT, OCS, FAAOMPT is an assistant professor and core faculty in the University of Mary Physical Therapy program in Bismarck, ND. He is a Board-Certified Orthopaedic Clinical Specialist through the American Physical Therapy Association and Fellow of the American Academy of Orthopaedic Manual Physical Therapy.

Jodi Young is the Director of Research in the Bellin College DSc in Physical Therapy Program. She is a Fellow of the American Academy of Orthopaedic Manual Physical Therapy. She completed her PhD through the University of Newcastle in Australia researching physical therapy dosing in patients with lower extremity injuries.

Dan Rhon is a clinician and active health services researcher. He has a Masters and Doctor of Science in Physical Therapy from Baylor University, a Doctorate of Physical Therapy from Temple University and a PhD from the University of Newcastle. He completed a clinical fellowship at Brooke Army Medical Center (Orthopaedic Manual Physical Therapy) and a postdoctoral research fellowship at the University of Utah.

Funding Statement

The authors report there is no funding associated with the work featured in the article.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions statement

KC and MS all developed the final study protocol, designed, and analyzed the data, and wrote the initial draft of the manuscript. DR and JY conceived the study idea, assisted with interpretation of results, provided feedback for drafts of the manuscript, and helped supervise the project process. All authors approved of the final version.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10669817.2024.2327127