Year 2021
September 2021


Abstract Title
The Inter-rater Reliability of a Revised Classification for Metatarsalgia to Guide Orthotic Intervention



Tan Tock Seng Hospital1, Woodlands Health2

Background & Hypothesis

Metatarsalgia is defined as pain under the second to fourth metatarsophalangeal joints. The prevailing classification divides Metatarsalgia into Primary (arising from anatomic abnormalities), Secondary (arising from abnormal forces through indirect mechanisms) and Iatrogenic aetiologies. This classification loosely delineates biomechanical risk factors leading to confusion in classifying individual cases. This subsequently hinders clear consideration for timely and appropriate orthotic intervention. Thus, we aim to develop and test the inter-rater reliability of a revised classification to better classify Metatarsalgia and accurately direct management.



An expert panel of three podiatrists formulated a classification system consisting of two classes (Mechanical and Non-mechanical), based on the presence or absence of abnormal biomechanics contributing to Metatarsalgia. This was tested against the current classification for the level of concordance using Fleiss’ Kappa amongst six experienced podiatrists (> six years of working experience with varied background of training) for ten anonymised cases of Metatarsalgia.


The current classification demonstrated fair agreement (K = 0.385, P < 0.001) amongst the raters whilst the proposed classification demonstrated moderate agreement (K = 0.577, P < 0.001). Furthermore, the proposed classification achieved perfect agreement for 70% of the cases as compared to just 30% of cases for the current classification.

Discussion & Conclusion

The proposed classification yielded better agreement amongst experienced podiatrists compared to the current classification. This may improve standardisation of orthotic interventions. Compared to other classifications, the proposed classification also addresses the presence of concurrent biomechanical risk factors. Future work could employ larger study designs with clinicians across different experience levels.