PT Critically Appraised Topics

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Critically Appraised Topic

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Clinical Scenario

The patient who led us to pursue this question was a 62 year old female with a medical diagnosis of piriformis syndrome and gait abnormality. The medical treatment to date included prescribed medications and physician’s advice. The physical therapy diagnosis was low back pain (LBP), bilateral lower extremity (LE) pain, poor balance, and gait abnormality. The patient responded well to the McKenzie extension approach at the first visit and was instructed to perform extension-in-lying 10 times every 2-3 hours at home. At her next visit, two weeks later, she had improved slightly and responded to manual overpressure performed by the physical therapist with increased motion and decreased pain. Two weeks later, however, her symptoms had worsened and she reported that she had returned to the physician and is scheduled to have an MRI.

Clinical Question

Is the McKenzie method or manual therapy a more effective intervention for the treatment of working adults experiencing LBP to decrease pain and improve function at the completion of treatment and at one year follow-up as measured by the Effect Size, Number Needed to Treat (NNT), Visual Analogue Scale (VAS), and a standardized functional outcome assessment tool such as the Oswestry Disability Index (ODI), Patient Specific Functional Scale (PSFS), or the Roland-Morris Questionnaire (RMQ)?

Clinical Bottom Line

Based on the results of the outcomes from Paatelma et al., Petersen et al., and Schenk et al. there is weak evidence in support of treating LBP with the McKenzie method, as compared to manual therapy. Though subjects treated with either method experienced decreased pain as well as functional improvement, those in the McKenzie group had better outcomes overall. This evidence included an effect size of 0.33 favoring the McKenzie method in functional improvements, according to the Paatelma, et al. study. A NNT of 8.89 for the McKenzie group was found for functional improvements in the Petersen et al. study. Finally, the Schenk et al. study found a NNT of 2.33 for the McKenzie group in decreased pain. The internal validity of the studies was good, with the main uncontrolled threat being extraneous variables. One of the studies also lacked power due to having a small sample size. We feel confident that we can generalize the results to our patient population because overall the studies included subjects similar in age to our clinical population with acute, subacute, and chronic LBP. On the other hand, convenience sampling was used for all of the studies, resulting in a less diverse patient population. Because manual therapy is such a broad category of treatment, we would be unable to replicate the progression of techniques used by the clinicians in these studies. Further research should be done comparing the McKenzie method to a specific approach of manual therapy, such as the Maitland Approach.