Back manipulation is a technique commonly used for lower back pain relief.
There is however, another very commonly used technique called joint mobilisation. Mobilisation is a technique used by physiotherapists .
Both types of techniques can be effective when used appropriately. It is likely that they:
A (not so )recent study (reference 2. below) looked at whether spinal manipulation was effective for lower back pain relief in acute back pain.
The title of the study is a bit misleading as it actually looked at back mobilisation techniques not manipulation. The results were surprising, the treatment made no difference at all!
Bear in mind that this study was only looking at people who had back pain for a very short time. There is no evidence that it does or does not work with chronic lower back pain.
A further meta analysis (1) looking at manipulation for chronic (longstanding) low back pain has also found limited evidence that its helpful - the authors state:
"High quality evidence suggests that there is no clinically relevant difference between Spinal Manipulative Therapy and other interventions for reducing pain and improving function in patients with chronic low-back pain"
1.Rubinstein SM, van Middelkoop M, Assendelft WJJ, de Boer MR, van Tulder MW. Spinal manipulative therapy for chronic low-back pain. Cochrane Database of Systematic Reviews 2011, Issue 2.
2. Hancock, M., Maher, P. C., Latimer, P. J., Prof Andrew, J. M., Cooper, M. C., Prof Richard, O. D., Spindler, M., & McAuley, P. J. "Assessment of diclofenac or spinal manipulative therapy, or both, in addition to recommended first-line treatment for acute low back pain: vol. 370, p. 1638.