From the Cochrane Library:
Spinal manipulative therapy = cracking backs.
“Spinal manipulative therapy (SMT) is an intervention that is widely practiced by a variety of health care professionals worldwide. The effectiveness of this form of therapy for the management of chronic low-back pain has come under dispute.
Low-back pain is a common and disabling disorder, which represents a great burden to the individual and society. It often results in reduced quality of life, time lost from work and substantial medical expense. In this review, chronic low-back pain is defined as low-back pain lasting longer than 12 weeks. For this review, we only included cases of low-back pain that were not caused by known underlying conditions, for example, infection, tumour, or fracture. We also included patients whose pain was predominantly in the lower back, but may also have radiated (spread) into the buttocks and legs.
SMT is known as a “hands-on” treatment of the spine, which includes both manipulation and mobilisation. In manual mobilisations, the therapist moves the patient’s spine within their range of motion. They use slow, passive movements, starting with a small range and gradually increasing to a larger range of motion. Manipulation is a passive technique where the therapist applies a specifically directed manual impulse, or thrust, to a joint, at or near the end of the passive (or physiological) range of motion. This is often accompanied by an audible ‘crack’.
In this updated review, we identified 26 randomised controlled trials (represented by 6070 participants) that assessed the effects of SMT in patients with chronic low-back pain. Treatment was delivered by a variety of practitioners, including chiropractors, manual therapists and osteopaths. Only nine trials were considered to have a low risk of bias. In other words, results in which we could put some confidence.
The results of this review demonstrate that SMT appears to be as effective as other common therapies prescribed for chronic low-back pain, such as, exercise therapy, standard medical care or physiotherapy. However, it is less clear how it compares to inert interventions or sham (placebo) treatment because there are only a few studies, typically with a high risk of bias, which investigated these factors. Approximately two-thirds of the studies had a high risk of bias, which means we cannot be completely confident with their results. Furthermore, no serious complications were observed with SMT.
In summary, SMT appears to be no better or worse than other existing therapies for patients with chronic low-back pain.”
Cracking joints is nothing more than a party trick. Go to your GP and get referred to a physio and save yourself some cash.