First metatarsophalangeal joint dorsiflexion resistance in individuals with plantar fasciopathy

Introduction

Plantar fasciopathy is a common foot-related musculoskeletal disorder. It has been hypothesized that this disorder could be linked to a dysfunctional windlass mechanism. However, no study to date has quantified this link to validate or refute this hypothesis. The first metatarsophalangeal joint (1st MPJ) dorsiflexion resistance test is a reliable test to evaluate the force required to initiate the windlass mechanism. Comparing the results of this test in individuals with and without plantar fasciopathy will allow for a better understanding of the relationship between plantar fasciopathy and the windlass mechanism. Thus, this study aimed to compare 1st MPJ dorsiflexion resistance in individuals with plantar fasciopathy and healthy controls. Additionally, this study aimed to explore the correlations between 1st MPJ dorsiflexion resistance and other commonly used foot orthopedic tests, specifically the supination resistance test and the Foot Posture Index.

Material and methods

Twenty participants with plantar fasciopathy and 20 healthy controls were recruited in this case-control study. First MPJ dorsiflexion resistance was quantified and compared between groups and between feet using a repeated measures ANOVA with one within-subject factor with two levels and one between-subject factor with two levels. It was also correlated with supination resistance and the Foot Posture Index.

Results

There were no significant differences in 1st MPJ dorsiflexion resistance between injured and healthy feet as well as control and plantar fasciopathy groups. There was a moderate to strong correlation (r = 0.674 to 0.891) between 1st MPJ dorsiflexion resistance and supination resistance in both groups. There was no significant correlation between 1st MPJ dorsiflexion resistance and the Foot Posture Index.

Conclusions

The lack of alterations in 1st MPJ dorsiflexion resistance among individuals with plantar fasciopathy implies a potential need to reconsider the biomechanical model, proposing that a dysfunctional windlass mechanism is associated with the development of plantar fasciopathy, may need reconsideration.