Back pain is one of the most common health problems in the industrialized world, with estimates that between 60% and 85% of the population will experience it at some point in their lives. Laboratory trials suggest that the use of shoe insoles might be beneficial in the prevention and treatment of back pain, by absorbing the shock of the foot striking the ground and supporting the foot in proper alignment. There are a variety of insoles available.
We included six trials that studied populations who did extensive standing and walking in the course of their daily jobs. Three prevention studies (2061 participants) examined the effects of both customized and non-customized insoles for the prevention of back pain. Three studies with mixed populations (256 participants) examined the effects of customized insoles for back pain without being clear whether they were aimed at primary or secondary prevention or treatment. None of the studies showed that insoles prevented back pain. No included trials assessed insoles exclusively for treatment for back pain.
Although half of the trials were of high methodological quality and therefore had a low potential for bias, the results should still be read with caution. Most of the trials examined specific young, highly active male populations. Finally, no long-term treatment and prevention data are available.
In conclusion, there is strong evidence that insoles do not prevent back pain, while the current evidence on insoles as treatment for low-back pain does not allow any conclusions. Better trials assessing the association between insoles and back pain are required before professional recommendation for the use of insoles become standard.
There is strong evidence that insoles are not effective for the prevention of back pain. The current evidence on insoles as treatment for low-back pain does not allow any conclusions.
High quality trials are required for stronger conclusions.
There is lack of theoretical and clinical knowledge of the use of insoles for prevention or treatment of back pain. The high incidence of back pain and the popularity of shoe insoles call for a systematic review of this practice.
To determine the effectiveness of shoe insoles in the prevention and treatment of non-specific back pain compared to placebo, no intervention, or other interventions.
We searched the following databases: The Cochrane Back Group Trials Register and The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL to October 2008; reviewed reference lists in review articles, guidelines and in the included trials; conducted citation tracking; contacted individuals with expertise in this domain.
We included randomised controlled trials that examined the use of customized or non-customized insoles, for the prevention or treatment of back pain, compared to placebo, no intervention or other interventions. Study outcomes had to include at least one of the following: self-reported incidence or physician diagnosis of back pain; pain intensity; duration of back pain; absenteeism; functional status. Studies of insoles designed to treat limb length inequality were excluded.
One review author conducted the searches and blinded the retrieved references for authors, institution and journal. Two review authors independently selected the relevant articles. Two different review authors independently assessed the methodological quality and clinical relevance and extracted the data from each trial using a standardized form.
Six randomised controlled trials met inclusion criteria: Three examined prevention of back pain (2061 participants) and three examined mixed populations (256 participants) without being clear whether they were aimed at primary or secondary prevention or treatment. No treatment trials were found. There is strong evidence that the use of insoles does not prevent back pain. There is limited evidence that insoles alleviate back pain or adversely shift the pain to the lower extremities.
Limitations
This review largely reflects limitations of the literature, including low quality studies with heterogeneous interventions and outcome measures, poor blinding and poor reporting.