An observational study in Achilles Tendinopathy (AT), sponsored by University Hospital, Ghent. Not yet recruiting at 1 site in Belgium. Open to participants aged 18 Years to 55 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-09.
Sponsored by University Hospital, Ghent · Observational
Study type: Observational study
Aim: To assess intratendinous pressure in individuals with and without midportion Achilles tendinopathy and investigate its correlation with tendon structure, patient characteristics, and pain symptoms.
Intervention: This is a non-interventional, observational study. Intratendinous pressure is measured using an invasive measurement method (e.g., Compass Universal Hg), used in accordance with its intended purpose.
Participants: Adults aged 18-55, both male and female, including patients with clinically diagnosed Achilles tendinopathy and healthy control participants.
Outcome measures:
Secondary:
Discussion: The study seeks to better understand whether intratendinous pressure is increased in symptomatic Achilles tendons compared to healthy individuals. It also examines whether there is an association with structural tendon changes, a range of patient-related factors and the clinical symptoms experienced by the patient. The findings may help refine the pathophysiological understanding of Achilles tendinopathy and support the development of future treatment strategies.
Achilles tendinopathy is a debilitating injury that is common among athletes, especially those involved in running sports. Around 30% of all runners exhibit Achilles tendinopathy with an annual incidence of 7-9%. Despite its high prevalence, the underlying pathophysiological mechanisms of Achilles tendinopathy remain incompletely understood. An emerging concept is the potential role of impaired intratendinous pressure homeostasis in the onset and progression of tendinopathy. A substantial body of in vitro and in vivo research concerning intratendinous pressure has already been conducted by Dr. Lauren Pringels, yet important knowledge gaps remain.
This observational study aims to investigate whether intratendinous pressure differs between individuals with and without Achilles tendinopathy. A secondary aim is to explore whether the intratendinous pressure correlates with tendon structure, patient characteristics, and pain symptoms.
Participants will be divided into two groups: patients clinically diagnosed with midportion Achilles tendinopathy, and asymptomatic healthy controls. The study aims to include approximately 25-30 participants per group. Participants will be recruited through sports physicians, physiotherapists, social media and study advertisements. All participants will undergo a standardized evaluation consisting of questionnaires, intratendinous pressure measurement, clinical examination and imaging assessments.
Patient-reported outcome measures will include:
Patient characteristics such as age, sex, height, weight, BMI, activity level, and symptom duration will be recorded.
Intratendinous pressure measurement will be performed using a simple, directly invasive measurement method (e.g., Compass Universal Hg), in accordance with its intended clinical use. The patient is positioned prone on the examination table, with the foot supported in 30° plantar flexion. In this position, the tension on the tendon is virtually zero, representing the resting condition. The invasive measurement method is introduced under ultrasound guidance and the pressure is determined at the center of the tendon. Needle positioning is done at a 30° angle, in a distal direction and parallel to the collagen fibrils, to minimize tissue trauma.
In patients with Achilles tendinopathy, intratendinous pressure is measured at the point where the tendon is most swollen. In asymptomatic individuals, intratendinous pressure is measured at a fixed point.
Imaging assessments include B-mode ultrasound and MRI scans to assess tendon structure, including tendon thickness, cross-sectional area and tendon volume.
397 studies on the registry are indexed under Tendinopathy; 77 are open to participants now.
This study's planned enrollment of 60 is close to the median of 61 across 50 observational studies indexed under Tendinopathy.
Browse Tendinopathy studies →University Hospital, Ghent is the lead sponsor of 689 studies on the registry; 160 are open to participants now.
Of its 5 completed or terminated interventional studies of FDA-regulated products, 4 (80%) have results posted.
Counted across the registry records on this site, refreshed daily.
Participants will be recruited from the outpatient clinics of UZ Gent and on the UGent campus, as well as through local physiotherapy practices and orthopedic clinics in the surrounding region. Recruitment methods include distribution of flyers, social media posts and direct referrals from healthcare providers. The study population consists of adults aged 18-55 years, including individuals with clinically diagnosed midportion Achilles tendinopathy and asymptomatic healthy controls.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria healthy controls:
Inclusion Criteria patients with achilles tendinopathy:
Exclusion Criteria patients with achilles tendinopathy:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Individuals without achilles tendinopathy
Diagnostic Test: Intratendinous pressure measurement
Patients with midportion achilles tendinopathy
Diagnostic Test: Intratendinous pressure measurement
Intratendinous pressure measurement will be performed using a simple, directly invasive measurement method (e.g., Compass Universal Hg), in accordance with its intended clinical use. The patient is positioned prone on the examination table, with the foot supported in 30° plantar flexion. In this position, the tension on the tendon is virtually zero, representing the resting condition. The invasive measurement method is introduced under ultrasound guidance and the pressure is determined at the center of the tendon. Needle positioning is done at a 30° angle, in a distal direction and parallel to the collagen fibrils, to minimize tissue trauma.
Intratendinous pressure
Intratendinous pressure in the achilles tendon (mm Hg)
Time frame: Single measurement at baseline
Patient reported outcome measures
VISA-A (Victorian Institute of Sport Assessment - Achilles) questionnaire ; score from 0-100 (higher score is better with 100 = no dysfunction, no pain)
Time frame: Single measurement at baseline
Patient reported outcome measures
TENDINS-A (TENDINopathy Severity Assessment - Achilles) questionnaire ; score ranging from 0-100 (higher score is worse with 0 = no dysfunction, no pain)
Time frame: Single measurement at baseline
Patient characteristics
Collection of demographic and clinical variables including: age in years
Time frame: Recorded at baseline
Patient characteristics
Collection of demographic and clinical variables including: sex (M/V/X)
Time frame: Recorded at baseline
Patient characteristics
Collection of demographic and clinical variables including: height in cm
Time frame: Recorded at baseline
Patient characteristics
Collection of demographic and clinical variables including: weight in kg
Time frame: Recorded at baseline
Patient characteristics
Collection of demographic and clinical variables including: weight and height will be combined to report BMI in kg/m²
Time frame: Recorded at baseline
Patient characteristics
Collection of demographic and clinical variables including: profession
Time frame: Recorded at baseline
Patient characteristics
Collection of demographic and clinical variables including: physical activity level (using a 6-point likert scale)
Time frame: Recorded at baseline
Patient characteristics
Collection of demographic and clinical variables including: duration of symptoms in weeks
Time frame: Recorded at baseline
Tendon structure
Assessment of tendon characteristics using ultrasound including: tendon thickness (anteroposterior diameter in cm)
Time frame: Single measurement at baseline
Tendon structure
Assessment of tendon characteristics using ultrasound including: cross-sectional area (cm²)
Time frame: Single measurement at baseline
Tendon structure
Assessment of tendon characteristics using ultrasound including: vascularity (color and power doppler signal)
Time frame: Single measurement at baseline
Tendon structure
Assessment of tendon characteristics using ultrasound including: tendon thickening (= anteroposterior diameter at thickest part of the tendon (cm) - anteroposterior diameter at 2cm proximal from calcaneal notch (cm))
Time frame: Single measurement at baseline
Tendon structure
Assessment of tendon characteristics using MRI including: tendon volume (cm²)
Time frame: Single measurement at baseline
Tendon structure
Assessment of tendon characteristics using MRI including: T2/T2\* mapping
Time frame: Single measurement at baseline
Perfusion pressure
Assessment of blood pressure to calculate perfusion pressure: ((diastolic pressure + 1/3 × \[systolic pressure - diastolic pressure\]) - intratendinous pressure)
Time frame: Single measurement at baseline
Plan to share: No
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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