Low back pain (LBP) is a leading cause of activity limitation, work absence, and disability throughout the world.1–7 An estimated 80% of the population will experience LBP in their lifetime.3,5 Low back pain is most likely to occur in the third decade of life; prevalence increases with age,2,4 and it has a recurrence of up to 85% in most individuals throughout their lifetime.3,5 The majority of cases of LBP are attributed to nonspecific causes and are frequently self-limiting within a month of onset; however, an increase in the number of patients who have transitioned from acute to chronic LBP has occurred in the past several years.1–7 Chronic LBP is disabling due to a combination of the physical and psychological impacts of pain in an individual.6
A wide variety of interventions may be utilized for patients with LBP throughout the course of the condition. No consensus has been reached relative to absolute efficacy of interventions by health care providers for patients with chronic LBP. However, the most current guidelines from the Centers for Disease Control and Prevention recommend nonpharmacologic therapy and nonopioid pharmacologic therapy as the preferred management strategies for patients with chronic pain.8 If opioid analgesic medications are used, they should be combined with nonpharmacologic interventions, such as massage, acupuncture, electrical stimulation, traction, spinal mobilization or manipulation, or exercise therapy, which are all routinely administered by a physical therapist.1,2,7
In New York State (NYS), spinal mobilization and manipulation are included as a mechanical means of intervention within the legal definition of physical therapy; more specifically, all licensed physical therapists are able to perform thrust manipulation in NYS.9 However, limited indications and parameters are provided for the clinical use of mobilization and manipulation. Physical therapists may mobilize or manipulate a joint to improve range of motion, decrease pain, and improve short-term outcomes for patients with LBP. Manipulation, or high-velocity low-amplitude thrust, is an appropriate intervention for patients with evidence supporting the subgrouping of patients who may optimally respond to lumbar manipulation and exercise for LBP.10–13 Patients who meet the clinical criteria for a manipulation clinical prediction rule (CPR) are more likely to benefit from spinal thrust manipulation.10–13 A CPR is a tool designed to assist in the classification process and improve decision making using evidence to determine which patients are likely to benefit from a specific treatment strategy. Despite the evidence in support of the use of spinal thrust manipulation in the treatment of patients with LBP, many clinicians choose not to intervene in this manner, and it is generally thought to be underutilized.10–13 The decision to manipulate may be based on several factors, including the patient population at hand, precautions and contraindications, clinician training and comfort with the techniques, a lack of understanding for the indications of spinal thrust manipulation, or a lack of knowledge relative to the use of manipulation under their state practice act.
In 2012, nearly all (99%) of the entry-level physical therapy programs in the United States were teaching thrust manipulation, and 91% of the programs indicated that their students were at or above entry-level expectations for implementing thrust manipulation upon graduation.14 According to faculty, increased exposure to thrust manipulation during clinical experiences would provide the greatest additional benefits to thrust manipulation education. Other studies15,16 have shown that clinical instructor perceptions influence student knowledge and application of thrust manipulation; thus, when students learn thrust manipulation in their curriculum, the carryover into clinical internships is of equal importance. If clinical instructors are underutilizing thrust manipulation in their practice, it may have a detrimental effect on student perceptions regarding the procedure and their application of thrust manipulation in subsequent clinical experiences. Therefore, having an understanding of how clinical instructors utilize thrust manipulation in the management of patients with LBP would be helpful to determine if other methods are necessary to provide the greatest benefits to thrust manipulation education.
Therefore, the primary purpose of this study was to evaluate the utilization of spinal thrust manipulation in the management of patients with LBP among physical therapists from NYS who serve as clinical instructors, as well as to evaluate physical therapist knowledge of a lumbar spine manipulation CPR and whether their NYS practice act allows for spinal thrust manipulation to be performed. A secondary purpose of this study was to assess differences between physical therapists who performed thrust manipulation and those that did not in terms of participant demographics (eg, gender, clinical experience), knowledge of the state practice act, board certification, and factors related to postgraduate training (eg, continuing education, residency/fellowship training). We hypothesized that generally, thrust manipulation would be underutilized in the management of patients with LBP; this underutilization would not be due to the lack of knowledge regarding when thrust manipulation is indicated according to a lumbar spine manipulation CPR or concern as to whether it is allowed by their state practice act. Rather, we hypothesized that the use of thrust manipulation would be related to board certification and factors related to postgraduate training (eg, continuing education, residency/fellowship training).
MATERIALS AND METHODS
This cross-sectional study explored the extent to which spinal thrust manipulation was utilized in the management of patients with LBP among NYS physical therapists through survey-based inquiry. The 25-item survey collected information on physical therapist demographics, the use of classification schemes and thrust manipulation in the treatment of patients with LBP, knowledge of a manipulation CPR, and their understanding of the NYS physical therapy practice act and its ability to allow physical therapists to perform spinal thrust manipulation (Appendix, Supplemental Digital Content 1, http://links.lww.com/JOPTE/A51). The lead author, who is a physical therapist and an attorney for the past 25 years with expertise in medical legal aspects of practice, initially developed the survey used in this study. The questions on the survey were consistent with previous survey-based literature in this area.17–20 The survey was then passed on to 3 content experts who were board certified and fellowship trained in orthopedic manual physical therapy with expertise in spinal thrust manipulation and survey-based research for pilot testing and review for item clarity and content. Their feedback was incorporated into the final draft of the survey. One content expert has been treating patients with orthopaedic dysfunction for 12 years and has been teaching orthopaedic content as a full-time faculty member for 7 years. He has published and presented research in the area of spinal disorders. The second content expert has 36 years of clinical experience specializing in orthopedics and orthopedic research, more than 20-peer reviewed publications in that area, and served as the director of a manual therapy fellowship for the past 10 years. The third content expert had 26 years of clinical experience specializing in orthopedics and orthopedic research with more than 50 peer-reviewed publications in that area.
We invited the 300 physical therapy clinics from NYS who serve as clinical instruction sites for the Department of Physical Therapy at the Daemen College in Amherst, NY, to participate in this survey-based study. The physical therapy clinics were mailed 1 envelope (via US Mail) that included a cover letter explaining the following: 1) the study's purpose, 2) the anonymous nature of the survey, 3) voluntary participation, 4) instructions on survey completion, and 5) return instructions. Three surveys and 3 return envelopes were also provided. The cover letter requested the survey be provided to 3 physical therapists who had treated patients with LBP within the past 6 months. Physical therapy clinics were initially contacted in May 2016, and surveys returned within 6 months were included in the analysis. Prior to recruiting physical therapists to participate, the study was approved by the Human Subjects Research Review Committee at Daemen College in Amherst, New York.
Statistical analyses were performed using the Statistical Package for the Social Sciences program (SPSS) for Windows, version 23 (IBM Corporation, Chicago, IL). For each variable, descriptive statistics were calculated as appropriate (frequencies for categorical data and means and SD for continuous data). Differences between physical therapists who performed thrust manipulation and those who did not were identified for the different variables using chi-square tests for categorical data and analysis of variance, with post hoc testing, and t tests for continuous data. The alpha level was set at P < .05.
We received 193 completed surveys from 105 clinics. Forty-three respondents were excluded from the data analysis for not having treated patients with LBP in the past 6 months. Thus, 150 surveys were used for data analysis (Table 1). Of the respondents, 54.4% (n = 81) were female and 45.3% (n = 68) were male (1 respondent did not answer). The mean number of years of physical therapy practice of the participants was 13.3 ± 9.9 years (range, 1–44 years). Table 1 presents data pertaining to clinical caseload, LBP continuing education attendance, achievement of American Board of Physical Therapy Specialties clinical specialist certification, or completion of an American Board of Physical Therapy Residency and Fellowship Education accredited orthopaedic/manual therapy residency or fellowship. Table 2 includes data pertaining to overall knowledge of the NYS physical therapy practice act. When asked if the NYS practice act allows physical therapists to perform spinal thrust manipulation, 63.9% (n = 92) of subjects correctly answered this question.
Of the 150 respondents, 41.3% (n = 62) answered “yes” to performing spinal manipulation on patients with LBP, and the majority of those physical therapists (77.4%) use the intervention between 0% and 25% of the time (Table 3). The primary reasons for physical therapists not performing spinal manipulation included a lack of experience or confidence with the techniques (n = 35), manipulation not being applicable to their patient population (n = 21), preference for only using nonthrust techniques (n = 6), and other treatments being more effective (n = 5). In terms of years of clinical practice and answering “yes” to performing spinal manipulation, physical therapists with fewer years of clinical experience were significantly more likely to utilize spinal thrust manipulation (Tables 3 and 4). For example, when compared with physical therapists with more than 20 years of experience, those with 1–5 years of clinical experience were significantly more likely to answer “yes” to performing spinal manipulation (53.5% vs 25.0%; P = .013). Physical therapists who held an American Board of Physical Therapy Specialties clinical specialist certification in orthopedics (P = .005) or had completed an American Board of Physical Therapy Residency and Fellowship Education accredited orthopaedic/manual therapy residency or fellowship (P = .03) were significantly more likely to perform thrust manipulation than those who were not (Table 4). Physical therapists who understood the NYS physical therapy practice act in terms of performing thrust manipulation (P = .014), attended continuing education regarding the management of patients with LBP (P = .007), and were male (P < .00001) were also significantly more likely to perform thrust manipulation for patients with LBP (Table 4).
Fifty-three percent (n = 80) of clinicians reported using a classification scheme when managing patients with LBP; the remainder of the respondents (46.7%, n = 70) reported that they did not use a classification scheme. When asked what classification scheme was utilized, 71 respondents (88.8%) used the McKenzie Method of Mechanical Diagnosis and Therapy21 and 9 respondents (11.3%) used the Treatment Based Classification Scheme.13 Further analysis demonstrated that respondents who answered “yes” to performing spinal manipulation on patients with LBP were significantly more likely to report using a classification scheme than those who did not report using manipulation (61.3% vs 44.3%; P = .04).
Thirty-seven percent (n = 23) of clinicians who reported manipulating patients with LBP reported using a CPR to determine candidates for manipulation; the remainder of the respondents (63%, n = 39) did not provide an answer or were unsure. When asked what CPR was utilized to determine candidates for manipulation, 18 respondents (78.3%) referred to the CPR developed by Flynn et al12; 3 respondents (13%) used the McKenzie Method of Mechanical Diagnosis and Therapy,21 and 2 (8.7%) reported using the work by Laslett et al.22
The primary purpose of this study was to evaluate the utilization of spinal thrust manipulation in the management of patients with LBP among physical therapists from NYS who serve as clinical instructors; we hypothesized that thrust manipulation would be generally underutilized in the management of patients with LBP. This hypothesis was based on the reports of prior studies that many clinicians choose not to utilize thrust manipulation in the treatment of patients with LBP.10–13 Mafi et al23 recently determined that the management of patients with LBP has relied increasingly on care that is not consistent with current clinical practice guidelines, which is also associated with an increased risk for prolonged disability and invasive procedures.24–27 Well-established clinical practice guidelines for routine LBP stress conservative management include the use of nonsteroidal anti-inflammatory drugs or acetaminophen, advice to stay active, and physical therapy, while avoiding early imaging or other aggressive treatments except in rare cases such as those demonstrating acute neurological compromise or other “red flags” such as a history of malignancy. One aspect of physical therapy management that has been supported by current clinical practice guidelines is spinal thrust manipulation. Our results somewhat reflect the guideline discordant care referred to by Mafi et al.23 For example, only 41.3% of respondents are performing spinal manipulation on patients with LBP, and for those who are using spinal thrust manipulation, the majority (77.4%) are using it less than 25% of the time with their patients. Therefore, despite emerging evidence to support the use of spinal thrust manipulation in the management of patients with LBP, our results suggest that the utilization of spinal thrust manipulation among physical therapists still remains relatively low. Thus, our hypothesis was supported.
Previous researchers have evaluated how frequently manipulation has been used in the management of patients with LBP. Freburger et al28 surveyed individuals with chronic LBP and determined that 29.7% had seen a physical therapist in the previous year; only 10.4% of patients received manipulation. More recently, Rhon et al29 examined the use of manipulative treatment for patients with LBP among various provider types during a 1-year period. They determined that 27.8% of all patients with lumbar disorders received manipulative treatment during the 1-year period and that 38.1% of these patients received their manipulative treatment from a physical therapist. In general, chiropractors used manipulation the most, and physical therapists the least. Adams and Sim30 surveyed physical therapists in the United Kingdom about their current practice of manipulation and determined that 86% identified themselves as “users” of manipulation. Mikhail et al20 had physical therapists describe their treatment practices for a typical patient with LBP and determined that the prevalence of use of interventions with strong or moderate evidence of effectiveness was 68%; however, only 3% of physical therapists reported that they would use spinal thrust manipulation. Interestingly, 90–96% of therapists reported that they would use interventions for which research evidence was limited or absent. Although the optimal rate for the use of spinal thrust manipulation is not known, it is reasonable to expect that the use of manipulation would exceed that of interventions with limited or absent supporting evidence, if physical therapists are choosing to practice in an evidence-based manner.31 In this present study, 41.3% of respondents reported using spinal manipulation on patients with LBP. Comparison between studies is challenging due to different study designs and methodologies, as well as varying physical therapist and patient populations. Nonetheless, it appears as if manipulation is being used with greater frequency as an intervention for patients with LBP by physical therapists in NYS; however, data from other studies suggest that manipulation is underutilized in comparison to other interventions with similar or lower levels of effectiveness.20,28
There are several reasons that manipulation may be underutilized in comparison to other interventions with similar or lower levels of effectiveness. Adams and Sim30 determined that anxiety about possible complications was a prominent reason for physical therapist's avoidance of manipulative procedures. Attitudes toward manipulation were generally positive, although overall respondents were uncertain as to whether its benefits outweighed its risks. In this current study, the most frequent reason cited by physical therapists for not using spinal thrust manipulation was a lack of experience or confidence with the techniques. Additionally, almost 40% of respondents in our study did not know that the NYS practice act allows physical therapists to perform spinal manipulation. Further efforts should be made to educate physical therapists on the utilization and performance of spinal thrust manipulation, and the low risk and complication rate associated with the techniques especially when patients are properly screened for the intervention. Also, a greater effort should be made to ensure that physical therapists are properly educated on their state practice act, especially when it relates to techniques or procedures that physical therapists are uncertain as to whether the benefits outweigh the risks. Perhaps passing a NYS jurisprudence examination prior to receiving a license to practice, as is done in 29 states, may assist in physical therapists better understanding their state's practice act.9
Researchers have identified the extent of thrust manipulation integration into entry-level physical therapy program curricula in 200432 and then again in 2012.14 Since the study in 2004,32 it was determined that the physical therapy profession had more clearly defined terminology associated with thrust manipulation, demonstrated integration of thrust manipulation into the curriculum, and optimized thrust manipulation instructional methods with clearer expectations for student competence.14 In 2012, nearly all (97%) of entry-level physical therapy programs believed that thrust manipulation was an entry-level skill, a considerable increase compared with 2004, when only 47% of faculty shared that belief.32 The results of our study may reflect the enhanced integration of thrust manipulation into educational curricula. For example, 53.5% of physical therapists with 1–5 years of experience in our study had integrated manipulation into their practice, compared with only 25% of physical therapists with more than 20 years of experience. Nonetheless, almost half of physical therapists with 1–5 years of experience in our study had not integrated manipulation into their practice. Physical therapist rationale for not using spinal thrust manipulation was a lack of experience or confidence. Perhaps, these results reflect the considerable variation in the number of hours allotted for thrust joint manipulation curricula and instruction regarding implementation of thrust manipulation into routine treatment planning, as well as how students are being assessed in entry-level educational curricula.14 Additionally, these results may be due to the limited availability and varied scope of clinical educational opportunities for entry-level students that include thrust manipulation.33 Because physical therapists tend to practice based on the knowledge gained in their professional training, integration of thrust manipulation into entry-level education program curricula, supplemented with appropriate clinical education opportunities, may offer the best opportunity to successfully increase the use of thrust manipulation.31
Previously, it has been difficult for clinicians to identify those individuals with LBP who will respond to thrust manipulation. However, emerging evidence suggests that we can identify individuals with LBP who respond to thrust manipulation with increasing certainty.10–13 Flynn et al12 developed a CPR, that was later validated,10 for identifying patients with LBP who are likely to respond rapidly to manipulation. The following 5 factors formed the CPR: 1) symptom duration of less than 16 days, 2) a score on the work subscale of the Fear-Avoidance Beliefs Questionnaire of less than 19, 3) hypomobility of the lumbar spine as assessed with posterior-to-anterior pressure, 4) internal rotation of at least 1 hip greater than 35°, and 5) symptoms not extending distal to the knee. When 4 of these 5 factors were present, patients were highly likely to improve (positive likelihood ratio = 24), whereas the presence of 2 or fewer factors was almost always associated with a failure to improve (negative likelihood ratio = 0.09). Therefore, if it is assumed that approximately 50% of all patients with LBP would improve with thrust manipulation, the likelihood of improvement would increase to 97% when at least 4 factors from the CPR were present and decrease to 9% when 2 or fewer factors from the CPR were present.12 Further study demonstrated that just 2 factors from the CPR (ie, symptom duration of less than 16 days and no symptoms extending distal to the knee) were associated with a good outcome with spinal manipulation (positive likelihood ratio = 7.2).34 Given the low risk related to manipulation of the lumbar spine35 and the likelihood of improvement in patients who meet the CPR, an attempt at spinal thrust manipulation clearly seems justified. Thirty-seven percent (n = 23) of clinicians in this study who reported manipulating patients with LBP reported using a CPR to determine candidates for manipulation; when asked what CPR was utilized to determine candidates for manipulation, the majority of respondents (78.3%) referred to the CPR by Flynn et al.12 However, the remainder of the respondents (63%, n = 39) in our study did not use a CPR to determine candidates for manipulation. Further research is necessary to assess the clinical decision making of clinicians who do not use a CPR to determine the patients likely to benefit from spinal thrust manipulation.
There were several limitations to this study that should be considered. This study evaluated whether physical therapists used spinal thrust manipulation as an intervention for patients with LBP. We did not assess psychomotor skills or the clinical decision making (beyond determining if a CPR was used) associated with the utilization and integration of spinal thrust manipulation, both of which could potentially influence patient outcome. Furthermore, we did not assess how many physical therapists used spinal nonthrust manipulation as an intervention for patients with LBP. This may have important implications because some authors have suggested that patients with LBP may benefit as much from nonthrust manipulation as from thrust manipulation.36,37 The physical therapists who participated in this study were a convenience sample of clinical instructors from NYS who were affiliated with a physical therapy program from a college in NYS. We had 150 participant surveys that were used for data analysis. There are 18,721 physical therapists licensed in NYS, suggesting that we sampled a very small percentage of physical therapists from NYS in this study.38 Thus, although our results are in general agreement with prior studies,20,28,29 they may not necessarily accurately represent physical therapists not affiliated with the college or others practicing in NYS. The survey was developed by one of the authors. The information included was based on the previous reports in the literature.17–20 Although the survey may appear to be generally valid on its face, it is not known if the results of this study accurately portray participants' actual clinical practice patterns. Furthermore, experts outside of the authorship team did not validate the survey. Our data may also reflect a response bias; perhaps, respondents with a special interest in manipulation were more likely to complete our survey. Despite these limitations, the findings offer a novel representation of the use of spinal thrust manipulation, and the factors that may potentially influence its utilization.
Despite emerging evidence to support the use of thrust manipulation in the management of patients with LBP, utilization of thrust manipulation among physical therapists still remains relatively low. Physical therapists who are board certified in orthopedics and/or residency/fellowship trained, attend continuing education, and better understand the NYS physical therapy practice act are more likely to perform thrust manipulation. The results of this study may have important implications for professional development and educational efforts regarding the training of physical therapists in the utilization of thrust manipulation. Also, a greater effort should be made to ensure that physical therapists are properly educated on their state practice act.
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