A total of 2.7 million patients present to US emergency departments annually for management of low back pain (LBP). Despite optimal medical therapy, more than 50% remain functionally impaired 3 months later. We performed a systematic review to address the following question: Among patients with nonchronic LBP, does spinal manipulation, massage, exercise, or yoga, when combined with standard medical therapy, improve pain and functional outcomes more than standard medical therapy alone?We used published searches to identify relevant studies, supplemented with our own updated search. Studies were culled from the Cochrane Register of Controlled Trials, Medline, EMBASE, CINAHL, and the Index to Chiropractic Literature. Our goal was to identify randomized studies that included patients with nonradicular LBP of <12 weeks' duration that compared the complementary therapy to usual care, sham therapy, or interventions known not to be efficacious, while providing all patients with standard analgesics. The outcomes of interest were improvement in pain scores or measures of functionality.We identified 2 randomized controlled trials in which chiropractic manipulation + medical therapy failed to show benefit vs medical therapy alone. We identified 4 randomized controlled trials in which exercise therapy + medical therapy failed to show benefit vs medical therapy alone. We did not identify any eligible studies of yoga or massage therapy.In conclusion, for patients with nonchronic, nonradicular LBP, available evidence does not support the use of spinal manipulation or exercise therapy in addition to standard medical therapy. There is insufficient evidence to determine if yoga or massage is beneficial.