Effectiveness of muscle energy technique in patients with nonspecific low back pain: a systematic review with meta-analysis

Low back pain (LBP) is a major cause of physical disability in the world. The origin of this condition can be due to differents causes, with a specific cause or of unknown mechanical origin,being characterized as unspecific. In this case a physical therapy treatment approach with manual therapy is relevant, which includes the muscle energy technique (MET) classified as a common conservative treatment for pathologies of the spine, mainly in LBP and disability. This study assessed the effectiveness of the muscle energy technique on nonspecific low back pain.

Patients with acute, subacute or chronic non-specific low back pain. The primary outcomes were pain and disability. This study was designed by a systematic review and meta-analysis, registered in PROSPERO (CRD42020219295). For the report and methodological definitions of this study, the recommendations of the PRISMA protocol and the Cochrane collaboration, were followed, respectively.

The search yielded 164 citations, which 19 were eligible randomised trials were included in the review (N.=609 patients with low back pain). The methodological quality of the studies averaged 4.2 points, with an interval of 2 to 7 points. Three RCTs showed satisfactory methodological quality (PEDro Score ≥6). For patients with chronic LBP, a significant result on pain (but with a small and clinically unimportant effect) in favor of MET versus other (MD=-0.51 [95% CI,-0.93 to -0.09] P=0.02, N.=376, studies=11, I2=80%). In patients with subacute LBP, MET enabled a significant and moderate effect to reduce pain intensity when compared to the control group (MD=-1.32 [95% CI,-2.57 to -0.06] P=0.04, N.=120, studies=3, I²=88%). No significant effects were observed for the disability.

MET is not considered an efficient treatment to improve the incapacity of the lumbar spine, but it may be beneficial in reducing the intensity of LBP, although showing a small clinical effect in chronic LBP and a moderate effect in subacute LBP.