Sensitivity and Tests for Evaluation of Plantar Fasciopathy

Overview

Plantar fasciopathy (PF), one of the leading causes of foot pain, affects up to one in ten individuals in their lifetime. Characterized by pain and structural alterations at the proximal insertion of the plantar fascia on the calcaneus, the term "PF" has replaced "plantar fasciitis," as degenerative tissue changes predominate over inflammatory processes. The pathogenesis of PF remains incompletely understood but appears to involve the gastrocnemius muscle, which is part of an integrated biomechanical unit including the calcaneus and the plantar fascia. Diagnosis is primarily based on clinical history and physical examination, while imaging modalities such as ultrasound and magnetic resonance imaging assist in excluding differential diagnoses. A simple clinical test to distinguish PF from other causes of heel pain, such as plantar fat pad syndrome or Baxter's nerve entrapment, could improve diagnostic efficiency. Given the biomechanical relationship between the Achilles tendon and the plantar fascia, and their shared association with gastrocnemius tightness, a clinical test adapted from Achilles tendon assessment may be useful for diagnosing PF. In 2003, the Royal London Hospital proposed a diagnostic approach for Achilles tendinopathy based on pain reduction during active ankle dorsiflexion, which reduces tension in the tendon. The same concept could be applied, with appropriate modifications, to PF. The present study aims to evaluate the sensitivity, specificity, reproducibility, and predictive value of localized tenderness at the medial calcaneal tuberosity and of a modified version of the Royal London Hospital Test in patients with PF. Secondarily, it will assess the reproducibility and prevalence of the Silfverskiöld test, supporting the concept of a biomechanical unit involving the triceps surae, calcaneus, and plantar fascia. Aim of this study is to evaluate the sensitivity, specificity, reproducibility, and predictive value of tenderness at the medial calcaneal tuberosity and of a modified version of the Royal London Hospital Test in patients presenting with clinical signs of PF. The modified version of the Royal London Hospital Test for PF has not yet been formally validated in the literature. However, the study was designed following the methodology adopted by Prof. Maffulli for the validation of the original test. Therefore, this is an exploratory study aimed at collecting preliminary data on this new diagnostic test. The secondary objectives of this study is to evaluate the reproducibility and prevalence of the Silfverskiöld test in the study population.

Detailed description

Plantar fasciopathy (PF) is one of the most common causes of foot pain, affecting a substantial proportion of the population במהלך their lifetime. It is characterized by pain and structural alterations at the proximal insertion of the plantar fascia on the calcaneus. The term "plantar fasciopathy" is preferred over "plantar fasciitis," as degenerative tissue changes and thickening are considered to predominate over inflammatory processes.

The pathogenesis of PF remains incompletely understood but is thought to involve the gastrocnemius muscle within an integrated biomechanical unit that includes the triceps surae complex, the calcaneus, and the plantar fascia. PF has a relevant clinical and socioeconomic impact, affecting quality of life and functional capacity, particularly in individuals exposed to prolonged standing or weight-bearing activities. Although most patients respond to conservative treatment, a subset develops persistent or refractory symptoms.

Diagnosis is primarily clinical, based on patient history and physical examination. Imaging modalities such as ultrasound and magnetic resonance imaging are mainly used to exclude alternative causes of heel pain. However, the relationship between imaging findings and symptom severity remains inconsistent, and there is currently no simple, standardized clinical test with established diagnostic accuracy for PF. The availability of a reliable bedside test capable of distinguishing PF from other causes of heel pain would improve diagnostic efficiency and clinical decision-making.

Given the anatomical and biomechanical relationship between the Achilles tendon and the plantar fascia, and their shared association with gastrocnemius tightness, adapting a clinical test originally developed for Achilles tendon assessment may provide a useful diagnostic approach. A method based on pain modification during active ankle dorsiflexion, which alters mechanical tension, may be transferable to the plantar fascia with appropriate modification.

This study is designed as an exploratory diagnostic investigation aimed at evaluating the performance of two clinical assessments: localized tenderness at the medial calcaneal tuberosity and a modified version of the Royal London Hospital Test adapted for PF. The study focuses on assessing diagnostic accuracy in terms of sensitivity, specificity, reproducibility, and predictive values in patients presenting with clinical signs consistent with PF. The modified test has not yet undergone formal validation, and this investigation is intended to provide preliminary evidence regarding its clinical applicability.

In addition, the study explores the role of gastrocnemius tightness within the proposed biomechanical framework by assessing the reproducibility and prevalence of the Silfverskiöld test in the same population.

The study adopts a controlled design with blinded assessment by multiple examiners under standardized conditions. Repeated evaluations within the same day are performed to assess intra- and inter-observer reliability. This methodological approach is intended to ensure robustness in the evaluation of diagnostic performance and to minimize measurement bias.

Overall, the study aims to contribute to the development and validation of simple, clinically applicable diagnostic tools for plantar fasciopathy, with potential implications for improving early diagnosis and optimizing patient management.

Interventions

• Diagnostic test Gastroc Sign
  Modified Version of the Royal London Hospital Test (Gastroc Sign) After identifying tenderness at the medial calcaneal tuberosity with the ankle in a neutral or slightly plantarflexed position, participants are asked to actively perform ankle dorsiflexion and plantarflexion with the knee extended. If the tenderness identified in the initial phase decreases or disappears during active dorsiflexion, the test is considered positive.
• Diagnostic test Tenderness at the Medial Calcaneal Tuberosity
  Palpation is performed with the ankle in a neutral position or slight plantarflexion, gently pressing the medial aspect of the plantar heel region starting from the palpable medial calcaneal tuberosity. Participants are asked to report whether tenderness is present or absent.
• Diagnostic test Silfverskiöld Test
  The Silfverskiöld test \[20\] is performed with the patient in the supine position. The examiner uses both hands: one stabilizes and locks the subtalar joint in a neutral position, while the other stabilizes the midtarsal joint and forefoot in supination, ensuring that movement is isolated to the tibiotalar joint. Tibiotalar dorsiflexion is measured under two conditions: * With the knee fully extended * With the knee flexed at 90 degrees Limited dorsiflexion in both positions indicates soleus

Primary outcome measures

• sensitivity [Time frame: from the morning to the afternoon of Day 1 - baseline]
• Specificity [Time frame: from the morning to the afternoon of Day 1 - baseline]
• Reproducibility (Reliability) [Time frame: from the morning to the afternoon of Day 1 - baseline]
• Predictive Value [Time frame: from the morning to the afternoon of Day 1 - baseline]

Secondary outcome measures (1)

• Reproducibility of the Silfverskiöld Test [Time frame: from the morning to the afternoon of Day 1 - baseline]

Eligibility criteria

Inclusion criteria

• PF group:

• Patients on the waiting list at Clinic I of the Rizzoli Orthopaedic Institute for surgical intervention with a diagnosis of recalcitrant PF lasting at least 12 months
• Age >18 years
• MRI of the foot and ankle negative for other local causes of pain included in the differential diagnosis of PF
• Negative electromyography for tarsal tunnel syndrome
• Control group:

• Age >18 years
• Outpatients followed at Clinic I for conditions unrelated to the foot and ankle, with no clinical history of foot pain or pathology in the preceding 12 months

Exclusion criteria

• PF and control groups:

• Minor patients
• Patients with diagnosed rheumatologic diseases currently under pharmacological treatment
• Patients with diabetes or diabetic neuropathy
• Pregnant women

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Diagnostic

Study locations

Italy · 1 center

• IRCCS Istituto ortopedico Rizzoli — Bologna

Publications

• Bolivar YA, Munuera PV, Padillo JP. Relationship between tightness of the posterior muscles of the lower limb and plantar fasciitis. Foot Ankle Int. 2013 Jan;34(1):42-8. doi: 10.1177/1071100712459173. PMID 23386760
• Nakale NT, Strydom A, Saragas NP, Ferrao PNF. Association Between Plantar Fasciitis and Isolated Gastrocnemius Tightness. Foot Ankle Int. 2018 Mar;39(3):271-277. doi: 10.1177/1071100717744175. Epub 2017 Dec 4. PMID 29198141
• Monteagudo M, de Albornoz PM, Gutierrez B, Tabuenca J, Alvarez I. Plantar fasciopathy: A current concepts review. EFORT Open Rev. 2018 Aug 29;3(8):485-493. doi: 10.1302/2058-5241.3.170080. eCollection 2018 Aug. PMID 30237906

Identifiers

NCT: NCT07567807 · 100/2025/Sper/IOR

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗