The Audrey Long article is commonly cited as one of the landmark articles for those of us that treat spines utilizing directional preference and centralization. As well it should be! The results are unbelievable. This researcher…I take that back…clinician performing research in the clinic published an article that, up until this time, was only speculation. How could patients not get better using evidence based practice? For a long time, the evidence was based on expert opinion and not really research. I enjoy reading the publications on spine and it is interesting to read the changes in the Clinical Practice Guidelines for Low Back, published in JOSPT over the years. Prior to the most recent publication, flexion based exercises were the rage and directional preference was only moderately supported. Thanks to clinicians such as Audrey Long, this type of treatment has gained more support in the practice guidelines. When I was in PT school (I sound like an old man, and year to year this is true, but not yet) this was a very small talking point in our curriculum. Students now come out of school with a better awareness, though not a true understanding, of the concept of directional preference.
A Critical Appraisal of Directional Preference Exercises Compared to Two Other Exercise Paradigms
P: For patients with low back pain, with or without leg pain, demonstrating a directional preference
I: is treatment with a directional preference
C: as compared to treatment in the opposite direction of the directional preference or an evidence based approach
O: more beneficial when compared with subjective outcome measures
Vincent Gutierrez, PT, MPT, cert. MDT
Pedro.org with the keyword terms “directional preference and low back pain”. Nine results were found and the article with the highest score was chosen.
Date of Search: February 15,2014
Long A, Donelson R, Fung T. Does it Matter Which Exercise? A Randomized Control Trial of Exercise for Low Back Pain. Spine 2004;29(23):2593-2602.
Eleven clinics, from five separate countries, participated in the study. Consecutive patients presenting for treatment of LBP, with or without leg pain, were asked to participate in the study. The inclusion criteria is as follows: consecutive patients with low back pain, with or without one neurological sign, age 18-65 years and demonstrating a directional preference. The exclusion criteria is as follows: cauda equina, two or more neurological signs, spinal fractures, post surgical, off work for one year or more due to low back pain, medical causes, uncontrolled medical conditions, pregnancy, inability to read English (except for those from Germany), patients with prior knowledge of, or specific physician referral for, the Mckenzie method, or no directional preference (DP) elicited.
Therapists credentialed or diplomaed in the McKenzie method performed the assessments. The directional preference was noted as either extension, flexion or lateral, but the subjects were shielded from the significance of directional preference. The subjects were then randomized to one of three groups: matched directional preference exercises, opposite directional preference (ODP) exercises, or evidence-based care (EBC). There were no baseline differences among the groups regarding demographics
The subjects attended at least three and no more than six sessions over the course of two weeks. Those in the DP group received exercises that matched the DP and were instructed to avoid all activities that increase intensity or radiation of symptoms. Those in the ODP group received exercises that were opposite to the DP, and the EBC group performed mid-range exerices and stretches for the hips and thighs. The final two groups also were instructed to return to remain active.
The outcome measures utilized in the study are as follows: back and leg pain intensity ratings using an 11 point visual analogue scale, the Roland Morris Disability Questionnaire (RMDQ), and medication use.
Five hundred three subjects were assessed and 230 demonstrated a DP as follows: 83% extension, 7% flexion and 10% lateral. Twenty-nine dropped out of the study at two weeks, and the remaining 201 were eligible for analysis. There were 36 withdrawals, which indicated that the subjects worsened or had no change in symptoms and were transitioned to alternative care. None of the DP group withdrew, but 16 in the ODP and 20 in the EBC withdrew. All outcome measures improved in the three groups over the course of two weeks, with the DP group demonstrating significant improvement compared to the ODP and EBC.
The authors satisfied eight of the ten questions regarding the Quality Appraisal Checklist. The subjects’ group design was not blinded to those enrolling the subjects and this was a comparison study of varying interventions, which indicates that a true control group was absent.
This study will have a direct impact for clinical therapists. Because this study compared three different interventions, opposed to identifying the efficacy of a single intervention compared to a control group, it mimicked clinical practice. The authors compared evidence based care with a directional preference treatment paradigm, which would be similar to a question asked in clinical practice.
Directional preference exercises are superior to performing exercises opposite to the directional preference or “evidence based care”. Patients that demonstrate a directional preference and are treated accordingly perform significantly better in outcomes measured in this study. There appears to be no harm in treating a patient with directional preference exercises, but the same does not hold true for performing exercises opposite of the directional preference or “evidence based care”.
The following is breakdown of the systems involved in “assessing” research articles.
- Were the subjects randomly assigned into groups?
Yes. The subjects were randomly assigned to one of three groups.
- Was each subject’s group assignment concealed from the people enrolling individuals in the study?
No. Because the study is a multi-centered study in outpatient practice, it was not acceptable to the authors to have patients drop out of the study due to changing therapists.
- Did groups have similar characteristics at the start of the study?
Yes. The authors note that there were “no differences among the three treatment groups in any baseline demographic characteristics or outcome measures.”
- Were subjects masked or blinded to their group assignment?
Yes. Although subjects couldn’t be blinded to the treatment, they were unaware of the specific grouping (i.e. matched vs unmatched vs EBP)
- Were clinicians and/or outcome assessors blinded to the subjects group assignment?
No and yes. Although the clinicians were not blinded, which is common in practice, the assessors of the outcome measures were blinded. The outcome measures were subjective measurements in order to minimize therapist bias.
- Did the investigators manage all of the groups in the same way except for the experimental investigation?
No. Because this is an intervention study in patient’s seeking treatment, it was impossible to withhold treatment to establish a true control group. The types of treatment for the opposite direction and EBP groups were vaguely described.
- Did the investigators apply the study protocol and collect follow-up data on all subjects over a time frame long enough for the outcomes of interest to occur?
No. There was a 12% dropout rate, which was anticipated by the authors when determining the number of patients needed to maintain a power of .90. Thirty-eight patients withdrew from the study, as opposed to dropped out, due to no improvement or worsening of symptoms in the EBP and unmatched group. Two weeks was long enough in order to assess change.
- Did subject attrition occur over the course of the study?
Yes. Twenty-nine subjects dropped out of the study, with 12 of the 29 dropping out due to no change or worsening of symptoms. Although these participants did not “drop out”, indicating that follow-up information was unattainable, 36 subjects withdrew early due to no change or worsening of symptoms. No subjects from the matched group withdrew. Those that withdrew completed the outcome measures prior to 2 weeks in order to seek alternative care.