title: The effectiveness of low-level laser therapy for nonspecific chronic low back pain: a systematic review and meta-analysis.
abstract: BACKGROUND
  In recent decades, low-level laser therapy (LLLT) has been widely used to relieve pain caused by different musculoskeletal disorders. Though widely used, its reported therapeutic outcomes are varied and conflicting. Results similarly conflict regarding its usage in patients with nonspecific chronic low back pain (NSCLBP). This study investigated the efficacy of low-level laser therapy (LLLT) for the treatment of NSCLBP by a systematic literature search with meta-analyses on selected studies.
  
  
  METHODS
  MEDLINE, EMBASE, ISI Web of Science and Cochrane Library were systematically searched from January 2000 to November 2014. Included studies were randomized controlled trials (RCTs) written in English that compared LLLT with placebo treatment in NSCLBP patients. The efficacy effect size was estimated by the weighted mean difference (WMD). Standard random-effects meta-analysis was used, and inconsistency was evaluated by the I-squared index (I(2)).
  
  
  RESULTS
  Of 221 studies, seven RCTs (one triple-blind, four double-blind, one single-blind, one not mentioning blinding, totaling 394 patients) met the criteria for inclusion. Based on five studies, the WMD in visual analog scale (VAS) pain outcome score after treatment was significantly lower in the LLLT group compared with placebo (WMD = -13.57 [95 % CI = -17.42, -9.72], I(2) = 0 %). No significant treatment effect was identified for disability scores or spinal range of motion outcomes.
  
  
  CONCLUSIONS
  Our findings indicate that LLLT is an effective method for relieving pain in NSCLBP patients. However, there is still a lack of evidence supporting its effect on function.
authors.affiliation: Department of Orthopedic Surgery, West China Hospital, West China Medical School, Sichuan University, No. 37 Wainan Guoxue Road, Chengdu, Sichuan Province, People's Republic of China. Zey.huang@gmail.com.|Duke Molecular Physiology Institute, Duke University School of Medicine, Duke University, PO Box 104775, Room 51-205, Carmichael Building, 300 North Duke Street, Durham, 27701-2047, NC, USA. Zey.huang@gmail.com.
authors.forename: ZeYu
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Orthopedic Surgery, West China Hospital, West China Medical School, Sichuan University, No. 37 Wainan Guoxue Road, Chengdu, Sichuan Province, People's Republic of China. dr.majun@foxmail.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.affiliation: West China School of Stomatology, Sichuan University, No. 14, Third Section, Renmin Road South, Chengdu, 610041, Sichuan Province, People's Republic of China. sallychen.jc@gmail.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Orthopedic Surgery, West China Hospital, West China Medical School, Sichuan University, No. 37 Wainan Guoxue Road, Chengdu, Sichuan Province, People's Republic of China. 492385233@qq.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Shen
authors.affiliation: Department of Orthopedic Surgery, West China Hospital, West China Medical School, Sichuan University, No. 37 Wainan Guoxue Road, Chengdu, Sichuan Province, People's Republic of China. peifuxing1951@163.com.
authors.forename: FuXing
authors.initials: F
authors.lastname: Pei
authors.affiliation: Duke Molecular Physiology Institute, Duke University School of Medicine, Duke University, PO Box 104775, Room 51-205, Carmichael Building, 300 North Duke Street, Durham, 27701-2047, NC, USA. vbk@duke.edu.|Division of Rheumatology, Department of Medicine, Duke University School of Medicine, Durham, NC, 27710, USA. vbk@duke.edu.
authors.forename: Virginia Byers
authors.initials: VB
authors.lastname: Kraus
mesh_terms: D059350:Chronic Pain / Q000601:surgery; D006801:Humans; D017116:Low Back Pain / Q000601:surgery*; D028022:Low-Level Light Therapy / Q000379:methods*