Research Review: Validation of a Clinical Prediction Rule to Identify Patients with LBP Likely to Respond to Stabilization Exercises

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In the next instalment of my Research Review Series for MedBridge Education, we discuss a recent randomized controlled study investigating the validity of a clinical prediction rule for identifying patients with low back pain likely to respond favoribly to a spinal stabilization program.

Study Design

Randomized Controlled Trial.

Subjects

One hundred five patients diagnosed with LBP and referred to physical therapy at 1 of 5 outpatient clinics of Clalit Health Services in the Tel-Aviv metropolitan area, Israel, were recruited for this study. Of these 105 patients, 40 were positive on the Stabilization CPR and 65 were negative. The most evident difference between baseline differences of groups was age, with those in the stabilization group being significantly younger (one of the items of the CPR is < 40 years old).

Inclusion Criteria: 18 to 60 years of age, primary complaint of LBP with or without associated leg symptoms (pain, paresthesia), and had a minimum score of 24% on the Hebrew version of the modified Oswestry Disability Index (MODI) outcome measure.

Exclusion Criteria: History indicating any red flags (malignancy, infection, spine fracture, cauda equina syndrome), 2 or more signs suggesting lumbar nerve root compression (decreased deep tendon reflexes, myotomal weakness, decreased sensation in a dermatomal distribution, or a positive SLR, crossed SLR, or femoral nerve stretch test), history of corticosteroid use, osteoporosis, or rheumatoid arthritis. Additionally, patients were excluded if they were pregnant, received chiropractic or physical therapy care for LBP in the preceding 6 months, could not read or write in the Hebrew language, or had a pending legal proceeding associated with their LBP.

Methods

Outcome Measures: Hebrew version of the modified Oswestry Disability Index (MODI) and Numerical Pain Rating Scale (NPRS).

Randomization: Based on a computer-generated list of random numbers, which was then stratified by CPR status to ensure that adequate numbers of patients with a positive and a negative CPR status would be included in each intervention group.

Evaluation: A physical examination was conducted that included a neurological screen to rule out lumbar nerve root compression. Next, lumbar active motion was evaluated, during which the presence of aberrant movement, as defined by Hicks et al, was determined. Bilateral SLR range of motion, segmental mobility of the lumbar spine, and the prone instability testing was then also conducted. The patients’ status on the CPR (positive or negative) was established based on the findings of the physical examination.

Interventions: Patients in both the Lumbar Stabilization Exercise group (LSE Group) and Manual Therapy group (MT) received 11 treatments over an 8 week period and a 12 visit, which consisted of solely a re-evaluation. The LSE group was first educated on the function and common impairments related to the lumbar stabilizing musculature, they were then taught to perform an isolated contraction of the transversus abdominis and lumbar multifidus through an abdominal drawing-in maneuver (ADIM) in the quadruped, standing, and supine positions. Once the patient could successfully perform these actions, the demands on the musculature were increased by the addition of various upper and lower extremity movements. Finally, during the seventh session, functional movements were added to their program. Those patients randomized to the MT group received several thrust and non-thrust mobilization techniques to their lumbar spine in addition to manual stretching of several hip and thigh muscle groups. Each treatment session included up to three manual techniques (one of which had to be a thrust technique). With regards to exercise, those in the MT group performed active range of motion and self-stretching exercises, but did not perform isolated spinal stabilization exercises. All variations and progressions of exercises and manual therapy techniques can be seen in the appendix of the research report.

Results

With regards to MODI, clinical significance could not be determined after 2-way interaction between treatment group and CPR status was calculated (p = 0.17). That being said, individuals who were positive on the CPR did demonstrate less disability at the end of the study compared to those who were negative (p = 0.02). Furthermore, amongst patients who were positive on the CPR, those who received LSE also demonstrated less disability following treatment compared to those who received MT. When the authors introduced a modified CPR, which consisted of positive prone instability test and presence aberrant movement, they did find a significant interaction with treatment for final MODI. Those positive on the modified CPR demonstrated superior outcomes compared to the group as a whole and also showed improved outcomes when receiving LSE compared to MT (p = 0.005).

Limitations

The most prevalent limitations include an inadequate sample size, which resulted in a limited overall power of the findings as well as the retrospective nature of some of the findings (i.e. modified CPR). Additionally, this study had a high drop-out rate for a study of its size with an overall drop-out rate of 22.8% (33% in the LSE group and 14% in the MT group). The lower dropout rate in the MT group could potentially be due to an attention affect due to the manual contact required for the interventions within this group compared to the LSE group. Additionally, while short-term results are important, understanding the long-term implications of either MT or LSE is of greater importance. This study only included an 8 week follow-up and it would be beneficial to see the long-term implications with a 6 or 12 month follow-up to gauge the overall effectiveness of the CPR and associated interventions. Finally, it should be noted that status on CPR was determined prior to group determination, which introduces an additional level of bias. Future studies should look at results with CPR determination post priori or following allocation to groups.

Clinical Implications

Manual therapy and spinal stabilization are two very common interventions utilized by physical therapists when treating low back pain. As manual therapy is common amongst clinicians and generally considered an effective treatment option, it provides an excellent reference value in the validation of the stabilization CPR. Unfortunately, the utility of the CPR as it was constructed could not be validated based on the findings of this study. Several factors could have played into this discrepancy including attention effect by those in the MT group, small sample size, and large dropout percentage. While the original CPR could not be validated, retrospectively an abbreviated CPR was identified and ‘validated’ based on the findings of the 2-way interaction between treatment group and modified CPR status. So, while this study seems like a knock to the current lumbar stabilization CPR, the study design and execution of the study cannot allow the CPR to be disregarded as all of the aforementioned limitations may have played a significant role in the study’s results. Additionally, the creation of an abridged CPR may have more value to clinicians long-term as it provided superior results and requires less factors to be evaluated by the clinician. However, the results must be taken with a grain of salt as a prospective evaluation of the modified CPR must be conducted in order to determine its utility. Clinical prediction rules and the effectiveness of spinal stabilization are polarizing issues within the physical therapy community and this study debatably provides support to the use of spinal stabilization and indicates that future research is needed to clear up the murkiness of the current stabilization CPR. When treating the lumbar spine, no treatment should be provided with every patient and Chad Cook, PT, PhD, FAAOMPT goes into great detail in his course, “Evidence-Based Treatment of the Lumbar Spine”, with regards to the use of spinal stabilization within the Treatment-Based Classification system.

Rabin A, Shashua A, Pizem K, Dickstein R, Dar G. A Clinical Prediction Rule to Identify Patients With Low Back Pain Who Are Likely to Experience Short-Term Success Following Lumbar Stabilization Exercises: A Randomized Controlled Validation Study. Journal of Orthopaedic & Sports Physical Therapy. 2014; 44(1): 6–18, B1–13. 

Effectiveness of Manual Therapy for Knee Pain

The following is another article written for the online, video-based physical therapy continuing education company MedBridge Education

Knee osteoarthritis (Knee OA) is one of the most prevalent and debilitating orthopedic complaints for 28% of adults over 45 years old and 37% of those over 65 years old in the United States. In addition, 1.6% of adults over the age of 60 have undergone total knee arthroplasty (Dillon et al). Improving the underlying mobility, strength, pain, and functional limitations associated with this pathology is a critical component of patient care. There are a number of interventions employed by physical therapists for individuals suffering from knee pain – some more effective than others. Amongst one of the more common, albeit controversial, is the use of manual therapy, or more specifically, joint mobilization.

In 2000, Deyle et al published an initial investigation into the potential effectiveness of manual therapy techniques in combination with exercise in the treatment of knee OA. In this randomized controlled trial, patients in the intervention group received manual therapy techniques based on their specific impairments, which potentially included passive physiologic and accessory joint movements, muscle stretching, and soft-tissue mobilization, applied primarily to the knee. However, if any additional deficits were found in other regions (i.e. hip, foot/ankle, lumbar spine), manual therapy techniques were directed at these areas. At the completion of the study, the intervention group achieved significant improvements in 6-minute walk distance and WOMAC score at 4 weeks and 8 weeks. Additionally, only 5% of those in the intervention group underwent total knee arthroplasty (TKA) in comparison to 20% in the control group. This study was a great first step, however as the control group only received subtherapeutic ultrasound for 10 minutes to the area of knee symptoms, further investigation was warranted.

Later in 2005, Deyle et al conducted a similar study with a control group, which included a standardized home exercise program. In this study, patients in the intervention group received 8 sessions of manual therapy treatment, which consisted of passive physiological and accessory movements, manual muscle stretching, and soft-tissue mobilization. These techniques were primarily applied to structures in the knee region opposed to the holistic approach previously used in the 2000 study. At the 4 week follow-up, WOMAC scores had improved by 52% in the clinic treatment group compared to 26% in the home exercise group, whereas both groups improved by approximately 10% in their 6-minute walk distances. Additionally, at the one-year follow-up, there was no significant difference between groups in either measure. This study gives credence to short-term functional improvements for manual therapy techniques, but not necessarily walking speed or capacity. While this does offer some evidence to support the inclusion of manual therapy, it also puts into question whether a home exercise program is an adequate comparison group.

More recently, Abbott et al conducted a randomized controlled trial comparing manual therapy, exercise, and combined manual therapy and exercise, and a usual care group in the treatment of hip and knee OA. The findings of this study were interesting, at the one year follow-up, both the manual therapy and exercise groups achieved statistically significant improvements with regards to reduction in WOMAC scores. Whereas, combined manual therapy and exercise did not meet this same significant improvement. Along with these findings, following the intention to treat analysis, all intervention groups improved but only usual care plus manual therapy and usual care plus exercise therapy achieved clinically significant reductions of >28 WOMAC points from baseline. Once again, manual therapy and exercise plus usual care improved, but did not meet the 28-point improvement threshold. In a secondary analysis of this trial by Pinto et al, it was determined that within the New Zealand healthcare system, both manual therapy and exercise offer a significant cost savings over usual care for OA treatment.

With this recent research, there does seem to be a fairly significant benefit to the utilization of manual therapy, however a multi-modal program consisting of manual therapy and exercise seems to be less effective than manual therapy in isolation. It should be taken into consideration that this conclusion was derived from one study and may not be a true representation of the patient population as a whole. In agreement with the benefits of manual therapy found by Abbott et al, a systematic review published by Jansen et al found a greater effect size with manual therapy and exercise (0.69) in comparison to either exercise therapy (0.38) or strength training (0.34) in isolation. Additionally, recent works by Rhon et al and Ko et al found significant increases in proprioception and functional performance when manual therapy was combined with exercise and perturbation exercises, respectively.

In addition to the varying degrees of effectiveness found in the aforementioned studies, it must be considered that not every patient with knee OA will respond similarly to any given therapeutic intervention. In order to help delineate those patients with knee OA who will respond favorably to hip mobilization, Currier et al proposed a Clinical Prediction Rule (CPR) to make this distinction. This particular study found that of those individuals who 2+ of the 5 variables present, following hip mobilization, the positive likelihood ratio was 12.9 and probability of success was 97% (success defined as a decrease of at least 30% on composite Numerical Pain Rating Scale score obtained during functional tests or a Global Rating of Change Scale score of at least 3). This CPR should be used with caution, however, as no validation study has been conducted to this date. While this CPR provides some idea as to which patients will respond favorably to manual therapy interventions, it should be understood that this decision must be made in conjunction with sound clinical reasoning following a thorough patient history and physical examination.

Alexis Wright, PT, PhD, DPT, FAAOMPT goes into great detail with regards to evidence-based decision making when deciding whether joint mobilization or manipulation will benefit your patient in her course, “Evidence-Based Examination of the Hip“. So, while the research is far from definitive regarding this specific intervention, manual techniques do appear to provide significant improvements in proprioceptive capacity, perceived physical disability, and pain levels for patients presenting with knee osteoarthritis.

Research Review: Manual Physical Therapy and Perturbation Exercises in Knee Osteoarthritis

Rhon et al, 2013

Study Design

Prospective, observational cohort study.

Subjects

Fifteen participants (7 male, 8 female) with a mean age of 55 years old were recruited from a convenience sample of consecutive patients evaluated for knee osteoarthritis (OA) at the Physical Therapy Clinic, Brooke Army Medical Center, San Antonio, Texas. With regards to severity, ten patients had bilateral symptoms, all 15 patients had radiographic signs of knee OA, and 10 had visible boney enlargement of the knee joint. Additionally, four of the included patients were active duty military personnel.

Inclusion Criteria: Utilizing criteria proposed by Altman (1991) and Altman et al (1986), the participants were included if they met at least one of the following three clinical clusters.

1. Knee pain for most days of the prior month: AND Crepitus with active motion and Morning stiffness in knee 38 years
2. Knee pain for most days of the prior month: AND Crepitus with active motion and Morning stiffness in knee > 30 minutes and Bony enlargement
3. Knee pain for most days of the prior month: AND No crepitus and Bony enlargement

Additional inclusion criteria include being eligible for care in a military medical treatment facility, minimum age 38 years old, and the ability to read, write, and speak sufficient English to complete the outcome tools.

Exclusion Criteria: Only periarticular pain or pain referred from another region (no joint pain), injections to the knee within the last 30 days, history of knee joint replacement surgery on involved limb, evidence of other systemic rheumatic condition (lupus, rheumatoid arthritis, psoriasis, or gout), and balance deficits from other non-musculoskeletal conditions (neurologic impairments, diabetic neuropathy, cerebellar disorders, or Parkinson disease)

Methods

Outcome Measures: The Western Ontario and McMaster Universities arthritis index (WOMAC), Global Rating of Change (GROC), Functional Squat Test (FST) evaluated with numerical pain rating scale (NPRS) and range of motion (ROM), and the Step-Up Test (SUT). Additionally, tolerance to treatment was determined by asking the participants a series of questions regarding whether their symptoms had gotten significantly worse at five different time points since their last visit. Time points included were immediately following treatment, several hours following treatment, that evening prior to bed, the following morning, and from the following morning until the follow-up (approximately 72 hours later).

Evaluation: The initial evaluation included a detailed history, review of systems, and physical examination. The history included questions regarding the duration, severity, location, and distribution of symptoms. The physical examination included functional tests, palpation of bony landmarks, ROM measurement, muscle length tests, and manual assessment of the joints and soft tissues of the lower extremity.

Interventions: Each patient was treated two times per week for four weeks and received both manual therapy and perturbation interventions. Visits included joint and soft-tissue mobilization, which was supplemented with stretching, ROM, and strengthening exercises. Additionally, each patient was provided with a home exercise program targeting their specific functional limitations. The manual therapy techniques were tailored to the impairments of each individual patient, however these interventions included varying grades of knee flexion, knee extension, and patella mobilizations. With regards to perturbation training, each patient was progressed based upon clinical reasoning and as tolerated by the individual patient. Each program generally started with more emphasis on manual therapy interventions and towards the end of the program, the focus switched to perturbation exercises.

Results

WOMAC: The mean WOMAC score demonstrated a statistically significant improvement from baseline to 6 months with a 46% improvement, which was well above the minimal clinically important difference (MCID) of 12%. Additionally, the total WOMAC score was significantly improved at the end of the 4 week intervention period and remained improved at the 6 month follow-up. Finally, the only WOMAC sub-scale that did not remain improved at the 6 month follow-up was the ‘Stiffness’ sub-scale.

GROC: At the one month follow-up, 87% of patients reached the 3 point change in GROC to identify a clinically important change. Changes decreased over time with 80% of patients still maintaining this threshold of change at 3 months and only 60% at the final 6 month follow-up. Additionally, and probably more importantly, 47% of patients met the threshold for ‘dramatic change’ (GROC > 6) at all time points.

FST: Following the 4 week intervention period, statistically significant improvements in NPRS and ROM during the FST were documented. An average decrease from 5 to 3 on the NPRS and an improvement from 29° to 35° with regards to ROM.

SUT: The Step-Up Test values also significantly improved at the 4 week evaluation with a mean improvement of 4-5 steps during the 15 second test. This translated to an average increase from 9 to 14 steps completed during the test.

Limitations

Due to the prospective cohort design of this study, no comparison group was included, thus no cause and effect relationship can be identified. Additionally, some of the improvements seen in this study could be attributed to other medical treatment many of the patients received. By 6 months five patients had received knee joint injections of either corticosteroid or viscosupplementation and two of those same patients received arthroscopic surgery. Of these patients receiving either injection or arthroscopic surgery, none reported improvement in symptoms immediately following the aforementioned procedures. Pain medication was used by 12 patients initially (10 patients daily; 2 patients as needed), including non-steroidal anti-inflammatory drugs and/or acetaminophen. However, it should be pointed out that at each of the follow-up points, fewer patients were taking medications than at baseline.

Clinical Implications

While no cause and effect relationship can be determined, this study does demonstrate theoretical effectiveness of a combined manual therapy and perturbation training approach to the treatment of knee osteoarthritis. This approach was associated with significant improvements in pain, function, and balance measures. There were several limitations evident within the study, however the potential positive impact of the interventions provided add to the current literature supporting perturbation and manual therapy techniques for patients suffering from knee osteoarthritis.

Rhon D, et al. Manual physical therapy and perturbation exercises in knee osteoarthritis. Journal of Manual & Manipulative Therapy. 2013; 21(4): 220–228.

Research Review: Validation of a Clinical Prediction Rule to Identify Patients with LBP Likely to Respond to Stabilization Exercises

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Study Design

Randomized Controlled Trial.

Subjects

One hundred five patients diagnosed with LBP and referred to physical therapy at 1 of 5 outpatient clinics of Clalit Health Services in the Tel-Aviv metropolitan area, Israel, were recruited for this study. Of these 105 patients, 40 were positive on the Stabilization CPR and 65 were negative. The most evident difference between baseline differences of groups was age, with those in the stabilization group being significantly younger (one of the items of the CPR is < 40 years old).

Inclusion Criteria: 18 to 60 years of age, primary complaint of LBP with or without associated leg symptoms (pain, paresthesia), and had a minimum score of 24% on the Hebrew version of the modified Oswestry Disability Index (MODI) outcome measure.

Exclusion Criteria: History indicating any red flags (malignancy, infection, spine fracture, cauda equina syndrome), 2 or more signs suggesting lumbar nerve root compression (decreased deep tendon reflexes, myotomal weakness, decreased sensation in a dermatomal distribution, or a positive SLR, crossed SLR, or femoral nerve stretch test), history of corticosteroid use, osteoporosis, or rheumatoid arthritis. Additionally, patients were excluded if they were pregnant, received chiropractic or physical therapy care for LBP in the preceding 6 months, could not read or write in the Hebrew language, or had a pending legal proceeding associated with their LBP.

Methods

Outcome Measures: Hebrew version of the modified Oswestry Disability Index (MODI) and Numerical Pain Rating Scale (NPRS).

Randomization: Based on a computer-generated list of random numbers, which was then stratified by CPR status to ensure that adequate numbers of patients with a positive and a negative CPR status would be included in each intervention group.

Evaluation: A physical examination was conducted that included a neurological screen to rule out lumbar nerve root compression. Next, lumbar active motion was evaluated, during which the presence of aberrant movement, as defined by Hicks et al, was determined. Bilateral SLR range of motion, segmental mobility of the lumbar spine, and the prone instability testing was then also conducted. The patients’ status on the CPR (positive or negative) was established based on the findings of the physical examination.

Interventions: Patients in both the Lumbar Stabilization Exercise group (LSE) and Manual Therapy group (MT) received 11 treatments over an 8 week period and a 12 visit, which consisted of solely a re-evaluation. The SG group was first educated on the function and common impairments related to the lumbar stabilizing musculature, they were then taught to perform an isolated contraction of the transversus abdominis and lumbar multifidus through an abdominal drawing-in maneuver (ADIM) in the quadruped, standing, and supine positions. Once the patient could successfully perform these actions, the demands on the musculature were increased by the addition of various upper and lower extremity movements. Finally, during the seventh session, functional movements were added to their program. Those patients randomized to the MT group received several thrust and non-thrust mobilization techniques to their lumbar spine in addition to manual stretching of several hip and thigh muscle groups. Each treatment session included up to three manual techniques (one of which had to be a thrust technique). With regards to exercise, those in the MT group performed active range of motion and self stretching exercises, but did not perform any exercises that included significant activation of the trunk musculature. All variations and progressions of exercises and manual therapy techniques can be seen in the appendix of the research report.

Results

With regards to MODI, clinical significance could not be determined after 2-way interaction between treatment group and CPR status was calculated (p = 0.17). That being said, individuals who were positive on the CPR did demonstrate less disability at the end of the study compared to those who were negative (p = 0.02). Furthermore, amongst patients who were positive on the CPR, those who received LSE also demonstrated less disability following treatment compared to those who received MT. When the authors introduced a modified CPR, which consisted of positive prone instability test and presence aberrant movement, they did find a significant interaction with treatment for final MODI. Those positive on the modified CPR demonstrated superior outcomes compared to the group as a whole and also showed improved outcomes when receiving LSE compared to MT (p = 0.005).

Limitations

The most prevalent limitations include an inadequate sample size, which resulted in a limited overall power of the findings and the retrospective nature of some of the findings (i.e. modified CPR). Additionally, this study had a high drop-out rate for a study of its size with an overall drop-out rate of 22.8% (33% in the LSE group and 14% in the MT group). The lower dropout rate in the MT group could potentially be due to an attention affect due to the manual contact required for the interventions within this group compared to the LSE group. Finally, while short-term results are important, understanding the long-term implications of either MT or LSE. This study only included an 8 week follow-up and it would be beneficial to see the long-term implications with a 6 or 12 month follow-up to gauge the overall effectiveness of the CPR and associated interventions.

Clinical Implications

Manual therapy and spinal stabilization are two very common interventions utilized by physical therapists when treating low back pain. As manual therapy is common amongst clinicians and generally considered an effective treatment option, it provides an excellent reference value in the validation of the stabilization CPR. Unfortunately, the utility of the CPR as it was constructed could not be validated based on the findings of this study. Several factors could have played into this discrepancy including attention effect by those in the MT group, small sample size, and large drop-out percentage. While the original CPR could not be validated, retrospectively a abbreviated CPR was identified and ‘validated’ based on the findings of the 2-way interaction between treatment group and modified CPR status. So, while this study seems like a knock to the current lumbar stabilization CPR, the study design and execution of the study cannot allow the CPR to be disregarded as all of the aforementioned limitations may have played a significant role in the study’s results. Additionally, the creation of an abridged CPR may have more value to clinicians long-term as it provided impressive results and requires less factors to be evaluated by the clinician. However, the results must be taken with a grain of salt as a prospective evaluation of the modified CPR must be conducted in order to determine its utility. Clinical prediction rules and the effectiveness of spinal stabilization are polarizing issues within the physical therapy community and this study debatably provides support to the use of spinal stabilization and future direction needed to clear up the murkiness of the current stabilization CPR.

Rabin A, Shashua A, Pizem K, Dickstein R, Dar G. A Clinical Prediction Rule to Identify Patients With Low Back Pain Who Are Likely to Experience Short-Term Success Following Lumbar Stabilization Exercises: A Randomized Controlled Validation Study. Journal of Orthopaedic & Sports Physical Therapy. 2014; 44(1): 6–18, B1–13. 

Research Review: Effect of Manual Therapy on Vertebral and Internal Carotid Blood Flow

In the next installment of my Research Review series for MedBridge Education, we will discuss a recent study that appeared in Physical Therapy Journal conducted by Thomas et al. The authors investigated the changes in vertebral and internal carotid blood flow during selective positions that are commonly associated with manual therapy techniques were assumed. This study provides additional evidence toward understanding the role of neck position on blood inflow to the brain.

Study Design

Experimental, observational magnetic resonance imaging (MRI) study.

Subjects

Twenty participants (10 male, 10 female) with a mean age of 33.1 years were recruited into the study. All participants had normal anatomy of their craniocervical arterial circulation, however three participants (15%) had dominance of one vertebral artery.

Inclusion Criteria: Healthy subjects, between the ages of 18 and 65 years old, no reported mechanical neck pain or headache.

Exclusion Criteria: Diagnosed inflammatory joint disease, any history of serious cervical spine trauma (i.e. fractures), any congenital disorder recognized as being associated with hypermobility or instability of the upper cervical spine, diagnosed vertebrobasilar artery insufficiency (VBI), claustrophobia or discomfort in confined spaces (standard contraindication for MRI), and any contraindication identified by the local health authority MRI safety screening questionnaire.

Methods

Experimental Conditions: While the MRI was being performed, the patients’ cervical spine was positioned in 9 distinctly different positions that simulate positions used in manual therapy techniques. These positions included: neutral position, left rotation, right rotation, left rotation with distraction, right rotation with distraction, left rotation localized to C1–C2, right rotation localized to C1–C2, distraction, and post-test neutral.

Outcome Measures: Blood flow in craniocervical arteries was measured with MRI using a phase-contrast flow quantification sequence. The arterial plane of section was selected to intersect the top of the atlas loop of the vertebral arteries at the level of the C1 vertebra, with imaging extending to just below the atlas loop. Average blood flow volume measured in milliliters per second was used as the primary test variable and was analyzed in neutral and each of the neck positions for each artery. The average blood flow volume in each artery then was compared between the neutral position and each of the experimental neck positions. Additionally, total blood supply to the brain was determined from the sum of average flow volume (mL/s) in both vertebral and both internal carotid arteries. A meaningful difference between the neutral position and any of the experimental conditions was determined to be > 10%.

Results

Average inflow to the brain in neutral was 6.98 mL/s and was not significantly changed by any of the test positions. According to the data collected, the lowest total blood inflow level was recorded during left rotation (6.52 mL/a). There was no significant difference in flow in any of the 4 arteries in any position from neutral, despite large individual variations. Although mean values of average flow volume were not significant for any position, there were certain individuals with marked flow changes in some positions. Flow generally decreased slightly for both the end-range rotation and distraction positions but increased in the other positions in comparison to neutral. Flow changes were all less than 10%, which is considered to be the normal variation for cerebral inflow.

Limitations

Secondary to restraints of the MRI and positioning of patients, full end-range rotation may not have been achieved. Additionally, some of the hand positions had to be altered from typical manual therapy techniques due to the constraints of the MRI set-up. None of the tested positions also included the thrust manipulation commonly used concurrently during a manual therapy procedure. Most notably, the results of this study should be cautioned as no subjects were included that presented with neck pain and/or headache symptoms.

Clinical Implications

Cervical manipulation is a polarizing topic amongst physical therapists and healthcare professionals as a whole. Many believe the risks are not worth the clinical benefits it provides to individuals suffering from mechanical neck pain. This study investigated blood flow to the brain during positions commonly associated with manipulative techniques and found only marginal changes in blood flow with multiple positions. What this study is not able to do (and wasn’t designed to do) is confirm the utility of positional tests for identifying those with blood flow restrictions or confirm that cervical thrust procedures do not involve blood flow changes (the subjects were healthy and there was no thrust used in this study). This sophisticated study adds nicely to the literature but clinicians still face the conundrum of identifying who may and my not be at risk during a thrust manipulation. Prior to intervening with cervical manipulative techniques, clinicians are urged to follow a thorough evaluation framework similar to that proposed by Flynn et al and the International Federation of Orthopaedic Manipulative Physical Therapists. Cervical manipulation should be implemented with caution and following a thorough subjective and physical examination when indicated by individual patient presentation.

Thomas LC, Rivett DA, Bateman G, Stanwell P, Levi CR. Effect of Selected Manual Therapy Interventions for Mechanical Neck Pain on Vertebral and Internal Carotid Arterial Blood Flow and Cerebral Inflow. Physical Therapy. 2013; 93(11): 1563–1574.

Research Review: Cervical Mobilization & Thoracic Manipulation versus Cervical Mobilization Alone

RR3

A randomized clinical trial recently published in the Journal of Orthopaedic & Sports Physical Therapy by Masaracchio et al evaluated the effectiveness of adding thoracic spine thrust manipulation to a program consisting of cervical spine non-thrust mobilization and cervical ROM exercises in the treatment of mechanical neck pain. While this study only looked into the short-term impact of this intervention strategy, it does provide some very important data that should help to guide our selection of manual techniques when treating these patients… [Continue Reading]

Cervical Manipulation… Is the Juice Worth the Squeeze? (Part 2)

In Part 1, the relative risks and important screening areas prior to cervical manipulation were discussed. In this second installment, the effectiveness and a theoretical framework for utilizing cervical manipulation will be laid out.

According to the Neck Pain Guidelines published by Cleland et al, manual therapy (mobilization and manipulation) was graded both an ‘A’ (strong evidence) and a ‘1’ (evidence from high-quality RCT, prospective, or diagnostic studies) in the treatment of neck pain. These guidelines advocate both manipulative and lower grade mobilization in reducing neck pain and cervicogenic headache symptoms. Published in the same year as the clinical guidelines, Walker et al conducted a RCT looking into the effectiveness of manual therapy and exercise in the management of mechanical neck pain. Those randomized to the manual therapy and exercise group (MTE) received treatments that ranged from cervical manipulation to soft-tissue mobilization and every technique in between. The intervention period lasted for 3 weeks with a total of 6 treatment sessions during this timeframe. At the conclusion of the study, those patients in the MTE group demonstrated statistically superior improvements in NDI scores at all 3 follow-ups, pain reduction at 3 and 6 weeks, perceived patient improvement on the GRC at all follow-ups, and overall treatment success rates were almost two-times as large for the MTE group in comparison to the minimal intervention group. These results bode well for a comprehensive manual therapy approach, but is there evidence to support the use of cervical manipulation in isolation?

Saavedra-Hernández et al recently published a RCT investigating the short-term effects of spinal manipulation in individuals suffering from chronic neck pain. In this study, patients were either randomized to an isolated cervical manipulation program (CMP) or a comprehensive manipulation program (cervical spine, cervicothoracic junction, and thoracic spine). After treatment (7 day follow-up), those in the CMP program demonstrated a decrease in pain from 4.8 to 2.7, NDI from 23.7 to 16.8, and increased ROM in all planes. While these values did reach statistical significance and this does lend evidence in support of cervical manipulation, those in the comprehensive program did achieve a greater reduction in disability than the CMP group. This lends support to a thorough manual therapy approach, but does not necessarily discredit the use of manipulation. With so many options available to the treating clinician, how do we know when to use manipulation?

Tseng et al investigated what predictors helped to identify those patients who would demonstrate immediate reduction in pain intensity, significant perceived improvement, and/or a high satisfaction level following cervical manipulation. After analyzing the outcomes of the 100 patients included and grouping them into either the ‘responder’ or ‘non-responder’ group, 6 variables were determined to be predictors of a positive response. These variables included initial scores on Neck Disability Index < 11.5, having a bilateral involvement pattern, not performing sedentary work greater than 5 h/day, feeling better while moving the neck, did not feel worse when extending the neck, and the diagnosis of spondylosis without radiculopathy. If 4 of these variables were present, the probability of success increased from 60% to 89% following manipulation. More recently, Puentedura et al conducted a similar study attempting to develop a clinical prediction rule identifying those who would respond favorably to cervical manipulation. Eighty-two consecutive patients presenting to an outpatient physical therapy clinic received manipulation of the cervical spine. Of the patients in this study, only 32/82 (39%) reported a favorable outcome. However, of those 32 who met the criteria for a favorable response, there were 4 variables that proved to be predictive. These items included symptom duration less than 38 days, positive expectation that manipulation will help, side-to-side difference in cervical rotation range of motion of 10° or greater, and pain with posteroanterior spring testing of the middle cervical spine. When > 3 of the 4 variables were present, the likelihood of a positive response increased from 39% to 90%. These are overwhelmingly positive findings, but it must be noted that these are merely preliminary findings and further supplemental research needs to be conducted in order to validate Puentedura and colleagues’ findings.

Many clinicians will argue that cervical manipulation should be abandoned in favor of less ‘dangerous’ interventions. The justification is primarily due to a lack of overwhelmingly superior outcomes compared to thoracic manipulation and/or cervical mobilization. While theoretically, these may be considered more conservative, are the outcomes really the same? Puentedura et al evaluated the outcomes of cervical manipulation versus those of thoracic manipulation in a small RCT. At the conclusion of the study, patients randomized to the cervical manipulation + exercise (CME) group demonstrated superior improvement in pain and disability in comparison to the thoracic manipulation + exercise group (TME). Additionally, there were no serious adverse events reported for either group, however the TME group reported significantly more side effects than the CME group (8 side effects versus 1). So, can we honestly say thoracic manipulation is safer and equally effective? This study seems to disagree. While this was a very small study (n = 24) and all subjects were treated by one clinician, it still offers sufficient evidence to compare the two interventions.

The second intervention that is typically used in place of manipulation is a lower grade joint mobilization (grades I-IV). Dunning et al set out to determine whether a combination of thoracic and cervical thrust manipulation was more effective than non-thrust techniques. At follow-up (48 hours post intervention), those in the manipulation group demonstrated superior improvements in disability, pain, atlatoaxial ROM, and motor performance of the deep neck flexor musculature. While this study only included data immediately following treatment, the benefits of manipulation seem to outweigh those of joint mobilization (in the short-term at least). This study is in agreement with an older study (Cassidy et al) that directly compared the short-term effects of cervical manipulation to mobilization. Both groups demonstrated similar improvements in ROM, but the manipulation group yielded superior improvements in pain intensity. However, contrary to the findings of these two studies, there have also been several studies that have found a lack of significant improvements between manipulation and mobilization. Hurwitz et al, Boyles et al, and Leaver et al all found a lack of discernible improvement in patient outcomes between manipulation and mobilization. Additionally, Saavedra-Hernández et al conducted a RCT comparing the effects of cervical manipulation to those of Kinesiotape in patients with mechanical neck pain. Both groups had similar reductions in neck pain and cervical ROM… This does not lend supporting evidence to Kinesiotape, rather it provides evidence against manipulation. Understandably, it is easy to use the findings of these studies as evidence to support the avoidance of manipulation, but what key concept are all of these studies lacking?

Cervical manipulation, actually manipulation in general, is not an intervention that should be used with every patient presenting with a particular diagnosis. There are specific sub-groups where manipulation is highly beneficial and then there are patients that will show no improvement with its use. Look at the Cochrane Review published on spinal manipulation for low back pain (LBP)… It was determined that, when analyzing all of the data, manipulation was no better than other inert interventions. However, based on the most recent developments in sub-grouping and treatment-based classification, matched treatment with regards to manipulation results in a positive likelihood ratio of 13.2. This is why one of the caveats included within the Cochrane Review is that more research needs to be done looking into the benefits of sub-grouping within this patient population. This is the route that cervical manipulation and its subsequent research needs to take (recent studies by Puentedura et al are a step in the right direction). As seen by the early results (improving probability of benefit from 39% to 90%), those patients who are likely to respond deserve to be provided the appropriate intervention. Not all patients need manipulated. In fact, not very many will need cervical manipulation at all, but to eliminate the intervention from those who will likely benefit seems counterproductive to me.

Based on the risk (albeit very minimal) and similar therapeutic effects from other seemingly less provocative interventions, I propose that cervical manipulation should be a potential intervention, but only for specific patient presentations. In general, I believe if you have exhausted other typical treatment approaches and the patient has not responded adequately, it may be time to consider more aggressive methods. My treatments are determined based on patient presentation and response to treatment, but if possible I try to progress from distal to proximal and from low grade to high velocity low amplitude in terms of manual therapy interventions. In addition, motor control, stabilization, and direction preference exercises must not be left out. As seen in several studies throughout this article, benefits are far superior when coupled with appropriate therapeutic exercise… This is further supported by a systematic review conducted by Gross et al who found combined treatment (manual therapy + exercise) to be superior to any treatment in isolation. It is our job as clinicians to develop and implement a comprehensive program utilizing manual therapy, exercise, pain modulation, and our patient’s beliefs and experiences. Use best evidence and clinical reasoning to determine an appropriate plan of care and your patient will demonstrate far superior outcomes compared to any intervention in isolation.

Thoracic Manipulation → Cervicothoracic Manipulation → Cervical Mobilization (Grade III/IV) → Meet CPR? → Cervical Manipulation (Grade V)

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