After reviewing the literature, we included three randomised controlled studies on the efficacy of manual therapy or osteopathy for infantile asymmetries of the head and neck. Haugen et al. showed that physiotherapy and manual therapy produced a change in symptoms similar to that seen with physiotherapy alone (17). Cabrera-Martos et al. suggested that manual therapy targeting the cervical spine may shorten treatment duration in infants with head asymmetries undergoing treatment with an orthotic helmet, but methodological limitations raise doubts about the result (18). Philippi et al. showed that a complex osteopathic intervention may potentially counteract asymmetry in infants with postural asymmetry, but found no differences between the osteopathy and placebo groups in defecation patterns, eating habits, sleep, mood and crying (19). We were unable to find any studies that examined the efficacy of chiropractic, or that investigated the risk of injury in a systematic manner.
Osteopathy and manual therapy have many common features, but there are key differences in the comparisons made by the efficacy studies in this review. Osteopathy was compared with placebo (19). Manual therapy was compared with conservative measures, but whereas Haugen et al. (17) designed their study to test the efficacy of manual therapeutic manipulation in isolation, Cabrera-Martos et al. (18) examined a more complex manual therapeutic approach. These differences mean that we were unable to combine the results in a meta-analysis, but the studies should nevertheless be considered in association with one another. One possible interpretation is that conventional physiotherapy and osteopathy both promote symmetrical development, but the specific manipulation or impulse technique used is not crucial to the end result.
The results we report in this article are consistent with other reviews on the topic (26–28), but some uncertainty remains over the conclusions. The small number of studies and participants means that there is uncertainty as to the true effect estimates. It could be argued that studies with alternative designs should also have been included. However, as infantile asymmetries often resolve spontaneously, uncontrolled studies would not provide reliable answers with respect to the issue of efficacy (29, 30).
There is anecdotal evidence that manipulation treatment has led to adverse events in adult patients (31). Adverse events have also been reported in children, but in the context of manipulation treatment performed on patients who had received an inadequate work-up (24, 25). Effective diagnosis and work-up are important to avoid delays in treatment and to prevent exacerbation of underlying disease (32, 33).
Irrespective of the risk of serious adverse events, it is important to consider whether treatment may cause the patient discomfort. In a survey of Norwegian manual therapists who treat infants, 25 % reported that children often begin to cry in association with treatment (3). It is ethically problematic to offer treatment of unproven efficacy to children, especially if the treatment entails discomfort (34). However, it is also important to be aware that not all infants taken to manual therapists, chiropractors or osteopaths due to asymmetries receive treatment with manipulation techniques (3). Half of Norwegian manual therapists report, for example, that they never manipulate the spine when treating infants, and that parental guidance is by far the most commonly used measure (3).
Data from Statistics Norway and the Norwegian Health Economics Administration show that approximately 8 % of all Norwegian infants are taken to manual therapists in their first year, often because of infantile asymmetry (3). This is in addition to treatments by chiropractors, osteopaths and other therapists. Why so many parents of infants seek help is unclear, but many may feel compelled to act if they perceive that their child differs from what is considered normal. A Finnish study showed that many concerns related to infantile asymmetries could probably be avoided if the parents receive good information and guidance when the child is born (35).
New parents are highly receptive to advice, and healthcare professionals should ensure that the advice given to parents, and the treatment given to children, is evidence-based and well-established. No causal relationship has been established between functional disorders of the neck and infantile asymmetries, and there is no reliable research to support the claim that untreated functional disorders of the neck give rise to complications and impairments later in life. This article, too, shows that the use of manipulation techniques to treat infantile asymmetries lacks evidence from research. Since the current evidence base consists of a small number of studies with few participants, it is difficult to draw firm conclusions, but our findings do not support the use of manipulation techniques in the treatment of infantile asymmetry.