The use of acupuncture for back pain is one of the most researched conditions in western medicine and the NHS UK website has the following to say (below).  It refers to 'western medical acupuncture. but applies equally to a trained British Acupuncture Council acupuncturist.

Western medical acupuncture is the use of acupuncture after a proper medical diagnosis. It is based on scientific evidence that shows the treatment can stimulate nerves under the skin and in muscle tissue.
This results in the body producing pain-relieving substances, such as endorphins. It is likely these substances are responsible for any beneficial effects seen with this form of acupuncture.

Lower and upper back pain can be managed, reduced and often eliminated with proper used of acupuncture, usually over a course of treatments.  

Having been a back pain sufferer myself I know the restrictions it can impose and the stress it can cause.  I work sensibly with my patients to form a realistic treatment plan and keep good track of progress. I also refer to colleagues within the Albany Street Clinic but also in other treatment centres (see my recommendations page).