J Manipulative Physiol Ther 2008 (Jul); 31 (6): 419–423 ~ FULL TEXT
Joyce E. Miller, DC, Kate Benfield, MChiro
Senior Clinic Tutor,
Lead Tutor MSc Advanced Chiropractic Pediatric Practice,
Anglo-European College of Chiropractic,
13-15 Parkwood Road,
Bournemouth, BH5 2DF
OBJECTIVE: The purpose of this study is to identify any adverse effects to chiropractic care occurring in the pediatric patient and to evaluate the risk of complications arising in the pediatric patient resulting from chiropractic care.
METHODS: A 3-year retrospective study of pediatric case files from the Anglo-European College of Chiropractic (AECC) (Bournemouth, England) teaching clinic practice in Bournemouth, England. All files (n = 781) of pediatric patients younger than 3 years of age were selected manually in sequential order from current files stored in the AECC clinic presenting to the AECC clinic during a specific period. Most (73.5%) patients presenting were 12 weeks of age or younger (n = 574).
RESULTS: Six hundred ninety-seven children received a total of 5242 chiropractic treatments, with 85% of parents reporting an improvement. Seven parents reported an adverse effect. There was a reaction rate of approximately 1 child in 100, or one reaction reported for every 749 treatments. There were no serious complications resulting from chiropractic treatment (reactions lasting >24 hours or severe enough to require hospital care).
CONCLUSIONS: This study shows that for the population studied, chiropractic manipulation produced very few adverse effects and was a safe form of therapy in the treatment of patients in this age group.
From the Full-Text Article:
The design of the study does not provide information on the effectiveness of pediatric chiropractic treatment but only documents the type of treatment given, parent perception of improvement in the child's condition, and reaction to treatment.
Although no parents reported a worsening of their child's presenting symptoms, 7 parents expressed that they believed their child had an adverse effect to the treatment they received for their child.
Six of these reported reactions involved increased crying after the treatment. Because it is known that adults may have mild reactions to SMT with increased soreness,  it is entirely plausible that infants (even with PSMT forces reduced relative to the patient's size and weight) may experience soreness that may increase irritability. It is difficult to compare these adverse reaction risk assessments with already published work in the literature as there have been no similar studies. The single systematic review  shows a very low risk of severe reactions to chiropractic PSMT (9 cases in a 30-year period). Our study showed no severe reactions and only 4 actual mild reactions.
It is also difficult to precisely compare these pediatric adverse effect rates to those of adults, as the negative side effects experienced by adults are different. The adverse reactions reported in the present study consisted of increased crying time and restlessness in 6 of 7 complaints. In adults, the range of mild side effects is reported to include local discomfort, headache, tiredness, and radiating discomfort.  The similarities are that the discomfort occurs the same day or one day after treatment and lasts a short period—less than 2 days in adults and less than 24 hours in infants. In children, there was no loss in activity of daily living as they could continue with normal mobility including sucking and eating. In adults, 11% of those with an adverse effect experienced loss in activity of daily living. 
Although this study has strengths, such as the large number of patients, there are also many weaknesses. For example, 2 patients were lost to follow-up. There was no long-term follow-up on 3 of the patients who had a mild reaction to treatment. It is also noted that many parents may not report reactions either because they may not recognize it as such, or they may be satisfied with the care and choose not to report after treatment. In effect, parental report has limitations. Furthermore, the records may not be totally reliable, and all reactions may not be reported. Because of these weaknesses, it is likely that there is underreporting of reactions to care in this population.
Furthermore, this is a difficult age group on which to collect accurate data. Data were collected only on the youngest of pediatric patients who cannot describe a negative effect for themselves. This is a difficult group to study, but essential, because they are generally left out of such studies merely because of inability to report. It is important this population affords the same respect as other patients who are old enough to complain. Parents are astute readers of infant's body language and its meaning, and their opinion must be accepted in such a study.
If the results of this study can be extrapolated to the wider infant and toddler population that presents to chiropractors, a parental report of an adverse reaction is likely to occur at the rate of approximately 1 for every 100 children presented to a chiropractic office for treatment. The actual rate of adverse reactions is expected to be about 1 case in approximately 1300 chiropractic treatments.
Application to Practice
Our findings suggest that when parents present their child for chiropractic care, the doctor of chiropractic must ensure that the parents understand that increased crying time after treatment may be a temporary reaction to care and can be expected to subside in less than 24 hours. This can be seen as a normal (but rare) reaction to treatment. This practice of informing the parent of a potential reaction has been instituted at the teaching clinic. Providers are also educated to be proactive and request information about any possible reaction to the last treatment in the routine history-taking in each visit. Furthermore, the Chiropractic Reporting and Learning System  developed as a part of clinical risk management to report all patient safety incidents has been expanded to include parent's reports of side effects to treatment. This has been instituted to prospectively collect all parental reports of negative reactions to pediatric treatment. This will result in a more accurate accounting of adverse reactions to treatment in our clinic.
More research is required into the issue of adverse effects occurring in all age groups of children who are treated by chiropractors. Adverse effects are best collected prospectively. Prospective investigations into the frequency and types of negative side effects are essential to document safety of chiropractic treatment for this age group and to gain knowledge of the types of reactions young children experience. This will allow chiropractors to inform parents of what is a normal reaction to chiropractic treatment and to detect any risks of our treatment in pediatric care. This study provides evidence that chiropractic treatment is a safe form of therapy for children younger than the age of 3 and documents that there were no serious complications resulting from chiropractic manipulation in this group of children of this age range.
Safety of chiropractic treatment for infants and children is under appropriate scrutiny.
Based on this analysis of 697 pediatric patients undergoing 5242 treatments, chiropractic manipulation resulted in very few adverse effects and is safe for young children and infants.