The association between plantar fasciitis and isolated gastrocnemius tightness

Abstract

Background: Plantar fasciitis is a painful inflammatory condition affecting the plantar aponeurosis of the foot. An association between plantar fasciitis and isolated gastrocnemius tightness has been postulated in published literature; however there have been few studies to prove this relationship. The aim of this study was to determine the association between plantar fasciitis and isolated gastrocnemius tightness. Material and Methods: This was a prospective cross-sectional cohort study over a three-month period comprising three groups: 45 patients with plantar fasciitis, 117 patients with foot and ankle pathology other than plantar fasciitis and 61 patients without foot and ankle pathology. Patients were examined for the presence of isolated gastrocnemius tightness using the Silfverskiӧld test. The data were analysed using STATA version 14. Statistical tests included the chi-square test, Student’s t-test and analysis of variance (ANOVA). Statistical tests were two-sided at α = 0.05. Results: Overall, 101/223 (45.3%) patients had isolated gastrocnemius tightness, 36/45 (80%) in the plantar fasciitis group, 53/117 (45.3%) in the other foot and ankle pathology group and 12/61 (19.7%) in the group without foot and ankle pathology. The difference in the prevalence of isolated gastrocnemius tightness amongst the three groups was statistically highly significant at p < 0.001. The prevalence of isolated gastrocnemius tightness was similar between acute and chronic symptoms of plantar fasciitis at 78.9% and 80.6%, respectively. Conclusion: There is a very strong association between plantar fasciitis and isolated gastrocnemius tightness, OR 16.3, 95% CI (6.1 – 42.5); p < 0.001 as well as a strong association between foot and ankle pathology other than plantar fasciitis and isolated gastrocnemius tightness, OR 3.4, 95% CI (1.6 – 7.0); p = 0.001 using the group without foot and ankle pathology as reference.

Level of Evidence: Level 2, Cross-sectional Cohort Study Key words: Plantar fasciitis, Silfverskiӧld test, Isolated gastrocnemius tightness