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

Are Small Effects for Back Pain Interventions Really Surprising?

There is reasonably strong evidence that some physical therapy interventions are effective (compared to minimal or no intervention) for patients with low back pain (LBP); however, the effect sizes are typically small. Many clinicians argue that this evidence is at odds with their daily clinical experience. There are several reasons that likely contribute to small effects in clinical trials of LBP and other musculoskeletal conditions. In this Viewpoint, the authors look at which of these reasons are beyond our control as clinicians and simply need to be acknowledged and understood, and which may provide insights into improving the design of future clinical trials of LBP and ultimately delivering better care to our patients. J Orthop Sports Phys Ther 2016;46(5):317-319. doi:10.2519/jospt.2016.0604.

Motor control exercise for acute non-specific low back pain

BACKGROUND

Motor control exercise (MCE) is used by healthcare professionals worldwide as a common treatment for low back pain (LBP). However, the effectiveness of this intervention for acute LBP remains unclear.

OBJECTIVES

To evaluate the effectiveness of MCE for patients with acute non-specific LBP.

SEARCH METHODS

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), four other databases and two trial registers from their inception to April 2015, tracked citations and searched reference lists. We placed no limitations on language nor on publication status.

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) examining the effectiveness of MCE for patients with acute non-specific LBP. We considered trials comparing MCE versus no treatment, versus another type of treatment or added as a supplement to other interventions. Primary outcomes were pain intensity and disability. Secondary outcomes were function, quality of life and recurrence.

DATA COLLECTION AND ANALYSIS

Two review authors screened for potentially eligible studies, assessed risk of bias and extracted data. A third independent review author resolved disagreements. We examined MCE in the following comparisons: (1) MCE versus spinal manipulative therapy; (2) MCE versus other exercises; and (3) MCE as a supplement to medical management. We used the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach to assess the quality of evidence. For missing or unclear information, we contacted study authors. We considered the following follow-up intervals: short term (less than three months after randomisation); intermediate term (at least three months but within 12 months after randomisation); and long term (12 months or longer after randomisation).

MAIN RESULTS

We included three trials in this review (n = 197 participants). Study sample sizes ranged from 33 to 123 participants. Low-quality evidence indicates no clinically important differences between MCE and spinal manipulative therapy for pain at short term and for disability at short term and long term. Low-quality evidence also suggests no clinically important differences between MCE and other forms of exercise for pain at short or intermediate term and for disability at intermediate term or long term follow-up. Moderate-quality evidence shows no clinically important differences between MCE and other forms of exercise for disability at short term follow-up. Finally, very low-quality evidence indicates that addition of MCE to medical management does not provide clinically important improvement for pain or disability at short term follow-up. For recurrence at one year, very low-quality evidence suggests that MCE and medical management decrease the risk of recurrence by 64% compared with medical management alone.

AUTHORS' CONCLUSIONS

We identified only three small trials that also evaluated different comparisons; therefore, no firm conclusions can be drawn on the effectiveness of MCE for acute LBP. Evidence of very low to moderate quality indicates that MCE showed no benefit over spinal manipulative therapy, other forms of exercise or medical treatment in decreasing pain and disability among patients with acute and subacute low back pain. Whether MCE can prevent recurrences of LBP remains uncertain.

Multiplanar lumbopelvic control in patients with low back pain: is multiplanar assessment better than single plane assessment in discriminating between patients and healthy controls?

OBJECTIVES

Patients with low back pain (LBP) commonly have lumbopelvic control deficits. Lumbopelvic assessment during sagittal motion is incorporated into commonly used clinical examination algorithms for Treatment Based Classification. The purpose of this study was to investigate whether combined assessment of lumbopelvic control during sagittal and frontal plane motion discriminates between people with and without LBP better than single plane assessment alone.

METHODS

Nineteen patients with LBP and 18 healthy control participants volunteered for this study. The active straight leg raise (ASLR) and active hip abduction (AHAbd) tests were used to assess lumbopelvic control during sagittal and frontal plane motion, respectively. The tests were scored as positive or negative using published scoring criteria. Contingency tables were created for each test alone and for the combined tests (both positive/both negative) with presence/absence of LBP as the reference standard to calculate accuracy statistics of sensitivity (sn), specificity (sp), likelihood (+LR and -LR), and diagnostic odds ratios (OR).

RESULTS

Active straight leg raise and AHAbd tests alone had sn of 0·63, 0·74, respectively, sp of 0·61, 0·50, respectively, and OR of 2·7, 2·8, respectively. The combined tests had sn = 0·89, sp = 0·60, and OR = 12·0. Forty percent of patients with LBP had control deficits in both planes of motion.

DISCUSSION

The AHAbd and ALSR tests appear to have greater diagnostic discrimination when used in combination than when used independently. A percentage of patients with LBP had control deficits in both planes, while others demonstrated uniplanar deficits only. These findings highlight the importance of multiplanar assessment in patients with LBP.

Motor control exercise for chronic non-specific low-back pain

BACKGROUND

Non-specific low back pain (LBP) is a common condition. It is reported to be a major health and socioeconomic problem associated with work absenteeism, disability and high costs for patients and society. Exercise is a modestly effective treatment for chronic LBP. However, current evidence suggests that no single form of exercise is superior to another. Among the most commonly used exercise interventions is motor control exercise (MCE). MCE intervention focuses on the activation of the deep trunk muscles and targets the restoration of control and co-ordination of these muscles, progressing to more complex and functional tasks integrating the activation of deep and global trunk muscles. While there are previous systematic reviews of the effectiveness of MCE, recently published trials justify an updated systematic review.

OBJECTIVES

To evaluate the effectiveness of MCE in patients with chronic non-specific LBP.

SEARCH METHODS

We conducted electronic searches in CENTRAL, MEDLINE, EMBASE, five other databases and two trials registers from their inception up to April 2015. We also performed citation tracking and searched the reference lists of reviews and eligible trials.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that examined the effectiveness of MCE in patients with chronic non-specific LBP. We included trials comparing MCE with no treatment, another treatment or that added MCE as a supplement to other interventions. Primary outcomes were pain intensity and disability. We considered function, quality of life, return to work or recurrence as secondary outcomes. All outcomes must have been measured with a valid and reliable instrument.

DATA COLLECTION AND ANALYSIS

Two independent review authors screened the search results, assessed risk of bias and extracted the data. A third independent review author resolved any disagreement. We assessed risk of bias using the Cochrane Back and Neck (CBN) Review Group expanded 12-item criteria (Furlan 2009). We extracted mean scores, standard deviations and sample sizes from the included trials, and if this information was not provided we calculated or estimated them using methods recommended in the Cochrane Handbook. We also contacted the authors of the trials for any missing or unclear information. We considered the following time points: short-term (less than three months after randomisation); intermediate (at least three months but less than 12 months after randomisation); and long-term (12 months or more after randomisation) follow-up. We assessed heterogeneity by visual inspection of the forest plots, and by calculating the Chi(2) test and the I(2) statistic. We combined results in a meta-analysis expressed as mean difference (MD) and 95% confidence interval (CI). We assessed the overall quality of the evidence using the GRADE approach.

MAIN RESULTS

We included 29 trials (n = 2431) in this review. The study sample sizes ranged from 20 to 323 participants. We considered a total of 76.6% of the included trials to have a low risk of bias, representing 86% of all participants. There is low to high quality evidence that MCE is not clinically more effective than other exercises for all follow-up periods and outcomes tested. When compared with minimal intervention, there is low to moderate quality evidence that MCE is effective for improving pain at short, intermediate and long-term follow-up with medium effect sizes (long-term, MD -12.97; 95% CI -18.51 to -7.42). There was also a clinically important difference for the outcomes function and global impression of recovery compared with minimal intervention. There is moderate to high quality evidence that there is no clinically important difference between MCE and manual therapy for all follow-up periods and outcomes tested. Finally, there is very low to low quality evidence that MCE is clinically more effective than exercise and electrophysical agents (EPA) for pain, disability, global impression of recovery and quality of life with medium to large effect sizes (pain at short term, MD -30.18; 95% CI -35.32 to -25.05). Minor or no adverse events were reported in the included trials.

AUTHORS' CONCLUSIONS

There is very low to moderate quality evidence that MCE has a clinically important effect compared with a minimal intervention for chronic low back pain. There is very low to low quality evidence that MCE has a clinically important effect compared with exercise plus EPA. There is moderate to high quality evidence that MCE provides similar outcomes to manual therapies and low to moderate quality evidence that it provides similar outcomes to other forms of exercises. Given the evidence that MCE is not superior to other forms of exercise, the choice of exercise for chronic LBP should probably depend on patient or therapist preferences, therapist training, costs and safety.

Trunk motor control deficits in acute and subacute low back pain are not associated with pain or fear of movement

BACKGROUND CONTEXT

A subgroup of patients with acute to subacute low back pain (LBP) presenting with trunk movement control deficits, pain provocation with segmental testing, and segmental hypermobility have been clinically identified as having movement coordination impairments (MCIs) of the trunk. It is hypothesized that these patients have proprioceptive, postural, and movement control impairments of the trunk associated with LBP. Although trunk control impairments have been identified in patients with chronic LBP, they have not been investigated in this subgroup or closer to symptom onset.

PURPOSE

The purpose of the study was to identify trunk motor control (postural control and movement precision) impairments in a subgroup of patients with acute to subacute LBP who have been clinically identified to have MCIs and determine association of these impairments with pain and fear of movement.

STUDY DESIGN/SETTING

The study design includes observational design, university biomechanics laboratory, and clinical practice.

PATIENT SAMPLE

Thirty-three patients with acute to subacute LBP presenting with trunk MCIs and 33 healthy controls matched with gender, age, and body mass index were identified.

OUTCOME MEASURES

Self-report measures included Numeric Pain Rating Scale, Oswestry Disability Index Questionnaire, and Fear-Avoidance Beliefs Questionnaire and physiologic measures included postural control and movement precision.

METHODS

Center-of-pressure movement was measured while subjects attempted to volitionally control trunk posture and movement while sitting on a platform with a hemisphere mounted underneath. This created an unstable surface that required coordinated trunk control to maintain an upright seated posture. Postural control was tested using eyes-open and -closed balance protocols. Movement precision was tested with a dynamic control test requiring movement of the center of pressure along a discrete path. Group trunk motor control performance was compared with analysis of variance and t test. Performance association with pain and fear of movement were assessed with Pearson correlations.

RESULTS

Patients' postural control in the eyes-closed condition (p=.02) and movement precision (p=.04) were significantly impaired compared with healthy controls, with moderate-to-large group difference effect sizes. These trunk motor control impairments were not significantly associated with the patients self-reported pain characteristics and fear of movement.

CONCLUSIONS

Patients with clinical identification of trunk MCIs demonstrated decreased trunk motor control, suggesting that impairments in proprioception, motor output, or central processing occur early in the back pain episode. This information may help to guide interventions to address these specific limitations, improving delivery of care.

Baseline Examination Factors Associated With Clinical Improvement After Dry Needling in Individuals With Low Back Pain

STUDY DESIGN

Quasi-experimental.

OBJECTIVES

To explore for associations between demographic, patient history, and physical examination variables and short-term improvement in self-reported disability following dry needling therapy performed on individuals with low back pain (LBP).

BACKGROUND

Dry needling is an intervention used with increasing frequency in patients with LBP; however, the characteristics of patients who are most likely to respond are not known.

METHODS

Seventy-two volunteers with mechanical LBP participated in the study. Potential prognostic factors were collected from baseline questionnaires, patient history, and physical examination tests. Treatment consisted of dry needling to the lumbar multifidus muscles bilaterally, administered during a single treatment session. Improvement was based on percent change on the Oswestry Disability Index at 1 week. The univariate and multivariate associations between 33 potential prognostic factors and improved disability were assessed with correlation coefficients and multivariate linear regression.

RESULTS

Increased LBP with the multifidus lift test (rpb = 0.31, P = .01) or during passive hip flexion performed with the patient supine (rpb = 0.23, P = .06), as well as positive beliefs about acupuncture/dry needling (rho = 0.22, P = .07), demonstrated univariate associations with Oswestry Disability Index improvement. Aggravation of LBP with standing (rpb = -0.27, P = .03), presence of leg pain (rpb = -0.29, P = .02), and any perception of hypermobility in the lumbar spine (rpb = -0.21, P = .09) were associated with less improvement. The multivariate model identified 2 predictors of improved disability with dry needling: pain with the multifidus lift test and no aggravation with standing (R(2) = 0.16, P = .01).

CONCLUSION

Increased LBP with the multifidus lift test was the strongest predictor of improved disability after dry needling, suggesting that the finding of pain during muscle contraction should be studied in future dry needling studies.

LEVEL OF EVIDENCE

Prognosis, level 1b.

External validation of a clinical prediction rule to predict full recovery and ongoing moderate/severe disability following acute whiplash injury

STUDY DESIGN

Retrospective secondary analysis of data.

OBJECTIVES

To investigate the external validity of the whiplash clinical prediction rule (CPR).

BACKGROUND

We recently derived a whiplash CPR to consolidate previously established prognostic factors for poor recovery from a whiplash injury and predicted 2 recovery pathways. Prognostic factors for full recovery were being less than 35 years of age and having an initial Neck Disability Index (NDI) score of 32% or less. Prognostic factors for ongoing moderate/severe pain and disability were being 35 years of age or older, having an initial NDI score of 40% or more, and the presence of hyperarousal symptoms. Validation is required to confirm the reproducibility and accuracy of this CPR. Clinician feedback on the usefulness of the CPR is also important to gauge acceptability.

METHODS

A secondary analysis of data from 101 individuals with acute whiplash-associated disorder who had previously participated in either a randomized controlled clinical trial or prospective cohort study was performed using accuracy statistics. Full recovery was defined as NDI score at 6 months of 10% or less, and ongoing moderate/severe pain and disability were defined as an NDI score at 6 months of 30% or greater. In addition, a small sample of physical therapists completed an anonymous survey on the clinical acceptability and usability of the tool. Results The positive predictive value of ongoing moderate/severe pain and disability was 90.9% in the validation cohort, and the positive predictive value of full recovery was 80.0%. Surveyed physical therapists reported that the whiplash CPR was simple, understandable, would be easy to use, and was an acceptable prognostic tool.

CONCLUSION

External validation of the whiplash CPR confirmed the reproducibility and accuracy of this dual-pathway tool for individuals with acute whiplash-associated disorder. Further research is needed to assess prospective validation, the impact of inclusion on practice, and to examine the efficacy of linking treatment strategies with predicted prognosis.

LEVEL OF EVIDENCE

Prognosis, level 1b.

An exploratory examination of the association between altered lumbar motor control, joint mobility and low back pain in athletes

Background:

Low back pain (LBP) is a common cause of lost playing time and can be a challenging clinical condition in competitive athletes. LBP in athletes may be associated with joint and ligamentous hypermobility and impairments in activation and coordination of the trunk musculature, however there is limited research in this area.

Objectives:

To determine if there is an association between altered lumbar motor control, joint mobility and low back pain (LBP) in a sample of athletes.

Materials and Methods:

Fifteen athletes with LBP were matched by age, gender and body mass index (BMI) with controls without LBP. Athletes completed a questionnaire with questions pertaining to demographics, activity level, medical history, need to self-manipulate their spine, pain intensity and location. Flexibility and lumbar motor control were assessed using: active and passive straight leg raise, lumbar range of motion (ROM), hip internal rotation ROM (HIR), Beighton ligamentous laxity scale, prone instability test (PIT), observation of lumbar aberrant movements, double leg lowering and Trendelenburg tests. Descriptive statistics were compiled and the chi square test was used to analyze results.

Results:

Descriptive statistics showed that 40% of athletes with LBP exhibited aberrant movements (AM), compared to 6% without LBP. 66% of athletes with LBP reported frequently self-manipulating their spine compared to 40% without LBP. No significant differences in motor control tests were found between groups. Athletes with LBP tended to have less lumbar flexion (63 ± 11°) compared to those without LBP (66 ± 13°). Chi-Square tests revealed that the AM were more likely to be present in athletes with LBP than those without (X2 = 4.66, P = 0.03).

Conclusions:

The presence of aberrant movement patterns is a significant clinical finding and associated with LBP in athletes.