Spine-related pain is a leading cause of disability and a major socioeconomic burden worldwide [1, 2]. In the United States, low back and neck pain account for more healthcare spending than any other condition [3]. People experiencing back or neck pain often seek care from complementary and alternative providers such as chiropractors [4]. Spinal manipulative therapy (SMT) is a commonly-used treatment technique employed by chiropractors that often involves a high-velocity, low-amplitude (HVLA) thrust [5]. The intended outcome is to restore motion of the affected joints, thereby decreasing pain levels and associated disability [6]. SMT is now often recommended as a viable option for conservative management of spinal pain [7].
While great strides have been made to better understand exactly how SMT decreases pain and improves function [8], the exact underlying mechanism remains unclear [9]. The benefits of SMT are likely multifactorial and include some combination of biomechanical, neurophysiological, and contextual components [10]. Biomechanical factors include the amount of force and speed produced by the thrust, resulting in movement of facet joints and changes in muscular reflex [6]. The fact that SMT also results in a neural response, both centrally and peripherally, is now widely accepted [11]. In addition to biomechanical and neurophysiological factors, it is likely that contextual factors such as the doctor-patient relationship can also have an impact on treatment outcomes associated with SMT [12].
Lack of a clear underlying mechanism for SMT leads to the possibility of misconceptions surrounding its utilization and effectiveness. For example, the audible pop, or cavitation, that often occurs results from HVLA thrust manipulation is often perceived as a benchmark of a successful intervention [13]. Evans and Lucas proposed a novel definition of SMT which includes the production of cavitation as a requirement for an intervention to be considered SMT [14]. Despite this, a recent systematic review found that the presence of an audible pop does not appear to impact the hypoalgesic effect attributed to SMT [15].
Similarly, it is common practice to select a specific target site for SMT via static or motion palpation of bony landmarks or joint segments. An attempt is then often made to deliver a specific thrust to that target site. Recent research, however, suggests that these aspects of the treatment might not be of particular importance. The delivery of SMT typically results in motion of multiple joint segments, and there seems to be no difference in clinical outcomes when considering a targeted versus a general thrust [16]. Few studies have explored the perceptions of patients and practitioners regarding what is valued during treatment sessions that include SMT. Maiers et al. [17, 18] used a qualitative approach to explore patients’ perceptions of chiropractic treatment for back and neck pain that included SMT. The researchers concluded that relationship dynamics between doctor and patient could be a key factor in perceiving benefit and satisfaction with treatment.
Similarly, Plank et al. [19] used semi-structured interviews to explore patients’ perceptions and expectations of various manual therapy treatments. They found that patients’ expectations of treatments were heavily influenced by their previous experiences and social environments, including interactions with the practitioner administering the treatment. These findings highlight the importance of the explanation of SMT that is given to the patient, which should align with their understanding of pain and be delivered in a reassuring way.
From an educational standpoint, there is wide variation in how SMT is taught within chiropractic institutions [20]. Stainsby et al. conducted a best-evidence synthesis to evaluate the effectiveness of various teaching methods on learning SMT [21]. The researchers found that a variety of simulation methods, including manikins and force-measuring devices, showed promise. However, the transferability of these skills and their relevance to clinical outcomes in patient populations remains unknown.
Additionally, there seems to be a weak association between subjective and objective measures of performance when evaluating trainees’ skills related to SMT. Pasquier et al. evaluated the relationship between biomechanical parameters, such as force-sensing tables, paired with direct observation from clinicians and feedback from recipients of SMT [22]. Their findings indicate that there seems to be some discrepancy between subjective assessments of performance and the objective measures that were used.
Despite this discrepancy, there is general consensus as to the key characteristics that should be included in the effective delivery of certain SMT procedures [23]. However, there exists a lack of agreement regarding best educational practices in relation to SMT. This lack of agreement could create obstacles when it comes to optimizing the teaching methods employed when advising trainees as to how best perform this skill.
Pinpointing the exact underlying mechanisms by which the therapeutic effects of SMT are produced, and which types of patients will have a favorable response to the treatment has been the focus of ongoing research. Additionally, it has proven to be a difficult endeavor. Gorell et al. attempted to synthesize quantifiable kinetic factors of SMT, such as preload and peak force, rate of force application, and thrust duration [24]. The researchers found that there is wide variability in these characteristics, likely due to individuality of clinicians and differences in measurement techniques.
In a recent individual participant data meta-analysis, researchers attempted to identify patient characteristics that might modify the treatment effects of SMT. However, they were unable to identify any such characteristics that would indicate that a patient is more likely to benefit from SMT compared to other treatments [25]. Future studies intend to explore variables associated with central sensitization, and what role those variables might play in the patient’s response to SMT [26]. In addition to quantitative measures of the effects associated with SMT, qualitative data could be useful to elucidate what treatment variables patients, experienced practitioners, and students learning to use SMT find important to achieve the desired outcome when working with patients experiencing spine-related pain.
Despite the progress that has been made to better understand the potential mechanisms of SMT and its treatment effects, a knowledge gap continues to exist when it comes to identifying the specific factors that contribute to the effective utilization of SMT. It is possible that this lack of understanding of the factors that contribute to the perceived treatment effect of SMT could lead to misconceptions regarding its utilization and benefits. This could affect teaching practices related to SMT, as well as implementation of the treatment into clinical practice. It is possible to illuminate this topic using qualitative research to explore the perceptions of various stakeholders involved in the utilization and education of SMT, including patients, interns, and clinicians. Therefore, the problem to be addressed in this study was the lack of a clear understanding of the factors that contribute to the perceived effect of SMT and the uncertainty surrounding how best to teach this skill.
The purpose of this study was to explore the perceptions of chiropractic clinicians, interns, and patients regarding what factors during a doctor-patient encounter contribute to the perceived treatment effect associated with SMT. This study provided the opportunity to achieve greater insight into the factors that contribute to the treatment effects associated with SMT by involving multiple stakeholders in the process, including clinicians, interns, and patients. This could help inform both educational practices and utilization in clinical practice.
This study sought to answer two research questions. First, what factors from the doctor-patient interaction contribute to the perceived effect of spinal manipulative therapy in patients with spine pain during a treatment visit that includes SMT? Secondly, how does the importance of these factors vary among the stakeholders involved, including patients, interns, and clinicians?