Pain Threshold Tests in Patients with Heel Pain Syndrome

Background: Pressure pain threshold (PPT) is a useful tool for evaluating mechanical sensitivity in patients suffering from various musculoskeletal disorders. However, no previous study has investigated PPT in the heel of patients experiencing plantar heel pain syndrome (PHPS). The aim of this study was to compare PPT levels and topographic presentation of sensitivity in the heel of patients with PHPS and in healthy controls. Methods: The reliability of PPT testing in patients with PHPS was assessed for intra- and interrater recordings. The PPT levels of 40 feet in each group were then assessed on 5 predetermined sites in the heel using a standardized measurement protocol. Patient functional status (FS) as measured by the Foot & Ankle Computerized Adaptive Test was employed as an external reference. Results: Multivariate analysis of covariance revealed no group differences for PPTs at all sites (P =.406). Age (P =.099) or BMI (P =.510) did not affect PPT values, although there was an effect on gender (P =.006). The analysis revealed significant differences between sites (P <.001) demonstrating a diverse topographic distribution. In the PHPS group, PPT levels at the anterior/medial, posterior/medial and central sites were significantly lower than at the posterior/lateral and anterior/lateral sites (P <.05). For the control group, PPT levels at the anterior/medial site were significantly lower than all other sites (P <.001). Conclusion: No significant differences were found between PPT of the PHPS patients and controls, therefore, PPT cannot be recommended as an assessment tool for these patients. The topographic distribution indicated low PPT levels at the anterior/medial area of the heel in patients with PHPS and controls. Level of Evidence: Level II, comparative study.