1 d he paper by Irving et al.1 in this issue is an xtensive, well-presented and constructive systemtic literature review in an area where there are any theories, yet little conclusive work comleted. Chronic plantar heel pain (CPHP) is a ommon musculoskeletal condition often seen by ealth care professionals. A number of risk facors have been reported in the literature and have ncluded overuse, over-training, excessive body eight, biomechanical changes to the properties f the soft tissue and/or altered biomechanics in articular excessive foot pronation. Occupations hat require extended periods of weight-bearing ave also been reported with the development of PHP. Irving et al. report that previous literature on PHP offers only a descriptive comparison between roups, limiting the statistical interpretation of he differences. Limited research has specifically ested risk factors by using appropriate statistial analysis for prediction. Irving et al. have synunderstand the impact of the major risk factors associated with this chronic condition. The authors postulate that, where such analyses have been applied, statistical assumptions and power standards have often been violated, especially with respect to determining appropriate sample sizes. A methodological quality assessment tool enabled the authors to evaluate key papers systematically and therefore to ensure internal and external validity and thus determine a minimum quality threshold for the selection of studies for the review. Although there is insufficient empirical evidence regarding validity of the application of a scoring system, a basic scoring system does give the reader a global picture of the quality of each study. Irving et al. go on to state that dynamic foot motion is not associated with chronic plantar heel pain and only a weak association was found with decreased first metatarsophangeal joint extension hesised the data by calculating the effect size nd odds ratios. Effect size is simply a way of uantifying the effectiveness of a particular risk actor. The use of Tables (2—7) helps the reader (Table 5). However, the concept of excessive foot motion, in particular rearfoot pronation, in the development of chronic plantar heel pain is a popular belief among clinicians and is commonly cited a r f