Effect of Foot Position During Rehabilitation of Achilles Tendinopathy on Tendon Mechanics and Symptoms.

NCT07623408 | Recruiting

• 1 other identifier: S68515
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

This study will investigate whether a 12-week load-based exercise program performed with an externally rotated foot position ("toes-out") leads to different changes in intra-tendinous sliding, symptoms, and function compared to a standard exercise program performed with a neutral foot position in individuals with mid-portion Achilles tendinopathy. In addition, physical activity will be monitored during and after the intervention to examine how daily loading patterns relate to symptoms and functional recovery over a 6-month period.

Conditions

Achilles Tendinopathy (AT)

Keywords

Achilles Tendinopathy; Exercise therapy program; Achilles Tendon; Rehabilitation; Foot position; homogeneous motions

Outcome Measures

Primary Outcomes (4)

• Intra-tendinous sliding between Achilles tendon layers (derived from ultrasound imaging and analyzed using a speckle tracking algorithm)

  Ultrasound images of the Achilles tendon will be recorded using a probe (Hitachi L64, Tokyo, Japan) put in an external probeholder during multiple rehabilitation exercises: Birise Bidrop Standing, Unirise Unidrop Standing Knee Extended, Unirise Unidrop Standing Knee Bent and squat. The device we will use is the Arietta 650, FUJIFILM, which allows to record B-mode ultrasound images. The probe will be placed distally on the Achilles tendon, just above the calcaneal insertion (used as reference point). Using a speckle tracking algorithm in Matlab, the displacement of 6 rows within the Achilles tendon is calculated. Intra-tendinous sliding is calculated as the relative difference between the displacement of the superficial and deep border.

  Measured during the pre and posttest, respectively the week before and after the 12-week exercise therapy program

• Clinical outcomes after Achilles Tendinopathy rehabilitation: Achilles Tendinopathy symptoms based on VISA-A questionnaire

  At pretest, 3, 6, 9, posttest, 15, 18, 21, and 24, the VISA-A questionnaire will be completed online. During the pre- and post-test assessments, participants will complete the questionnaire on a laptop provided in the lab, ensuring it is administered online and in the same manner as throughout the intervention, where they fill it in at home. The VISA-A questionnaire is an 8-item survey used to assess the severity of Achilles tendinopathy. It evaluates pain, daily functional activities, and sporting ability, with scores ranging from 0 to 100, where a score of 100 indicates no symptoms.

  Pretest (one week before the 12-week program), Posttest (one week after the 12-week program), and at week 3,6,9,15,18,21 and 24.

• Clinical outcomes after Achilles Tendinopathy rehabilitation: Achilles Tendon functionality based on heel-rise test

  Heel-rise test: participants perform as many heel-raises as possible at a frequency of 25 per minute (controlled by a metronome). The test will be discontinued when the participant does not reach maximum height, cannot keep the frequency, cannot keep the knee straight or stops due to pain or fatigue. By using an application, the foot will be filmed and heel work will be calculated.

  Pretest (one week before the 12-week program) and Posttest (one week after the 12-week program)

• Clinical outcomes after Achilles Tendinopathy rehabilitation: Achilles Tendon functionality based on hopping till pain test

  • Hopping till pain: the participant hops on a single leg at a pace of 2 jumps per second (controlled by a metronome) where the goal is to achieve 25 pain-free hops, but the test will be stopped when the participant starts to experience pain.

  pretest (one week before the 12-week program) and posttest (one week after the 12-week program)

Secondary Outcomes (9)

• Questionnaire Data: Quality of Life (SF-12 questionnaire)

  Pretest (one week before the 12-week training program), Posttest (one week after the 12-week training program), week 3,6,9,15,18,21,24

• Doppler Vascularity

  Pretest and posttest, respectively one week before and after the 12-week exercise therapy program

• Morphological features of the Achilles tendon (free Achilles tendon length and volume)

  Pretest and posttest, respectively one week before and after the 12-week exercise therapy program

• Lower extremity biomechanics during rehabilitation exercises: kinematics, kinetics, muscle activations, muscle forces and cumulative Achilles Tendon load through musculoskeletal modeling (assesed with 3D motion and ground reaction force capturing)

  During the pretest and posttest in the lab, respectively one week before and after the 12-week training program

• Physical activity throughout the training program

  Daily for 6 months: 12 weeks during the training program and 12 weeks after the training program.

Study Arms (2)

Toes-out Training Group

EXPERIMENTAL

Patients in this group will perform the 12-week load-based exercise program, and will execute all exercises daily througout the full program with toes-out (the feet horizontally outwards rotated). For this toes-out angle, their individual, most comfortable angle is chosen.

Other: 12-week adaptive, load-based exercise therapy protocol for Achilles Tendinopathy

Neutral Training Group

ACTIVE COMPARATOR

Patients in this group will perform the 12-week load-based exercise program, and will execute all exercises daily througout the full program with a neutral foot position.

Other: 12-week adaptive, load-based exercise therapy protocol for Achilles Tendinopathy

Interventions

12-week adaptive, load-based exercise therapy protocol for Achilles Tendinopathy OTHER

A 12-week progressive, load-based exercise program was developed, consisting of four daily exercises with gradually increasing tendon load over time. The program was based on the exercise battery and according Achilles Tendon loading index described by Baxter et al. (2021) and included a wide variety of 30 exercises (heel raise variations, step exercises, squats, lunges, jump variations, ...). A new exercise was introduced every four days, while weekly supervised sessions ensured correct execution and allowed for adjustments based on patient tolerance (e.g., excessive knee loading, too high pain scores during specific exercises, …). This flexible approach enabled gradual progression of each participant's daily load index according to individual capacity. An estimated time of 20-30 minutes daily is needed to execute all the daily exercises.

Neutral Training Group; Toes-out Training Group

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• PATIENTS WITH ACHILLES TENDINOPATHY:
• Voluntary written Informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures.
• Age between 18 and 65 years old
• BMI between 18.5-30
• Showing history of intermittent episodes of Achilles tendon pain lasting more than 3 consecutive weeks within the past 6 months.
• Presenting palpable focal thickening of the Achilles tendon.
• Having pain originating from the Achilles tendon on palpation of thickened tendon and on loading activities (such as running, jumping).
• Showing sonographic evidence of tendinopathy, i.e. focal thickening and hypoechocity, consistent with previously reported sonographic characteristics diagnosed of tendinopathy.

Sponsors & Collaborators

• KU Leuven: lead
• Universitaire Ziekenhuizen KU Leuven: collaborator

Study Sites (1)

KU Leuven

Leuven, Vlaams-Brabant, 3000, Belgium

RECRUITING

Related Publications (23)

• Lecompte L, Crouzier M, Bogaerts S, Scheys L, Vanwanseele B. Reduced Intratendinous Sliding in Achilles Tendinopathy During Active Plantarflexion Regardless of Horizontal Foot Position. Scand J Med Sci Sports. 2024 Jun;34(6):e14679. doi: 10.1111/sms.14679.

  PMID: 38898554 BACKGROUND

• Lecompte L, Crouzier M, Bogaerts S, Vanwanseele B. Patients with Achilles Tendinopathy Show Reduced Intratendinous Sliding during Dynamic Exercises. Med Sci Sports Exerc. 2026 Jun 1;58(6):1149-1158. doi: 10.1249/MSS.0000000000003942. Epub 2026 Jan 22.

  PMID: 41572520 BACKGROUND

• de Vos RJ, van der Vlist AC, Zwerver J, Meuffels DE, Smithuis F, van Ingen R, van der Giesen F, Visser E, Balemans A, Pols M, Veen N, den Ouden M, Weir A. Dutch multidisciplinary guideline on Achilles tendinopathy. Br J Sports Med. 2021 Oct;55(20):1125-1134. doi: 10.1136/bjsports-2020-103867. Epub 2021 Jun 29.

  PMID: 34187784 BACKGROUND

• Turner J, Malliaras P, Goulis J, Mc Auliffe S. "It's disappointing and it's pretty frustrating, because it feels like it's something that will never go away." A qualitative study exploring individuals' beliefs and experiences of Achilles tendinopathy. PLoS One. 2020 May 29;15(5):e0233459. doi: 10.1371/journal.pone.0233459. eCollection 2020.

  PMID: 32469914 BACKGROUND

• Thorpe CT, Udeze CP, Birch HL, Clegg PD, Screen HR. Specialization of tendon mechanical properties results from interfascicular differences. J R Soc Interface. 2012 Nov 7;9(76):3108-17. doi: 10.1098/rsif.2012.0362. Epub 2012 Jul 4.

  PMID: 22764132 BACKGROUND

• Tardioli A, Malliaras P, Maffulli N. Immediate and short-term effects of exercise on tendon structure: biochemical, biomechanical and imaging responses. Br Med Bull. 2012 Sep;103(1):169-202. doi: 10.1093/bmb/ldr052. Epub 2012 Jan 25.

  PMID: 22279080 BACKGROUND

• Slane LC, Thelen DG. Non-uniform displacements within the Achilles tendon observed during passive and eccentric loading. J Biomech. 2014 Sep 22;47(12):2831-5. doi: 10.1016/j.jbiomech.2014.07.032. Epub 2014 Aug 8.

  PMID: 25150898 BACKGROUND

• Sancho I, Willy RW, Morrissey D, Malliaras P, Lascurain-Aguirrebena I. Achilles tendon forces and pain during common rehabilitation exercises in male runners with Achilles tendinopathy. A laboratory study. Phys Ther Sport. 2023 Mar;60:26-33. doi: 10.1016/j.ptsp.2023.01.002. Epub 2023 Jan 10.

  PMID: 36640640 BACKGROUND

• Robinson JM, Cook JL, Purdam C, Visentini PJ, Ross J, Maffulli N, Taunton JE, Khan KM; Victorian Institute Of Sport Tendon Study Group. The VISA-A questionnaire: a valid and reliable index of the clinical severity of Achilles tendinopathy. Br J Sports Med. 2001 Oct;35(5):335-41. doi: 10.1136/bjsm.35.5.335.

  PMID: 11579069 BACKGROUND

• Radovanovic G, Bohm S, Peper KK, Arampatzis A, Legerlotz K. Evidence-Based High-Loading Tendon Exercise for 12 Weeks Leads to Increased Tendon Stiffness and Cross-Sectional Area in Achilles Tendinopathy: A Controlled Clinical Trial. Sports Med Open. 2022 Dec 20;8(1):149. doi: 10.1186/s40798-022-00545-5.

  PMID: 36538166 BACKGROUND

• van der Plas A, de Jonge S, de Vos RJ, van der Heide HJ, Verhaar JA, Weir A, Tol JL. A 5-year follow-up study of Alfredson's heel-drop exercise programme in chronic midportion Achilles tendinopathy. Br J Sports Med. 2012 Mar;46(3):214-8. doi: 10.1136/bjsports-2011-090035. Epub 2011 Nov 10.

  PMID: 22075719 BACKGROUND

• Passini FS, Jaeger PK, Saab AS, Hanlon S, Chittim NA, Arlt MJ, Ferrari KD, Haenni D, Caprara S, Bollhalder M, Niederost B, Horvath AN, Gotschi T, Ma S, Passini-Tall B, Fucentese SF, Blache U, Silvan U, Weber B, Silbernagel KG, Snedeker JG. Shear-stress sensing by PIEZO1 regulates tendon stiffness in rodents and influences jumping performance in humans. Nat Biomed Eng. 2021 Dec;5(12):1457-1471. doi: 10.1038/s41551-021-00716-x. Epub 2021 May 24.

  PMID: 34031557 BACKGROUND

• Maffulli N, Sharma P, Luscombe KL. Achilles tendinopathy: aetiology and management. J R Soc Med. 2004 Oct;97(10):472-6. doi: 10.1177/0141076809701004. No abstract available.

  PMID: 15459257 BACKGROUND

• Kujala UM, Sarna S, Kaprio J. Cumulative incidence of achilles tendon rupture and tendinopathy in male former elite athletes. Clin J Sport Med. 2005 May;15(3):133-5. doi: 10.1097/01.jsm.0000165347.55638.23.

  PMID: 15867554 BACKGROUND

• Gheidi N, Kernozek TW, Willson JD, Revak A, Diers K. Achilles tendon loading during weight bearing exercises. Phys Ther Sport. 2018 Jul;32:260-268. doi: 10.1016/j.ptsp.2018.05.007. Epub 2018 May 10.

  PMID: 29906737 BACKGROUND

• Franz JR, Slane LC, Rasske K, Thelen DG. Non-uniform in vivo deformations of the human Achilles tendon during walking. Gait Posture. 2015 Jan;41(1):192-7. doi: 10.1016/j.gaitpost.2014.10.001. Epub 2014 Oct 12.

  PMID: 25457482 BACKGROUND

• Fernandez MR, Athens J, Balsalobre-Fernandez C, Kubo M, Hebert-Losier K. Concurrent validity and reliability of a mobile iOS application used to assess calf raise test kinematics. Musculoskelet Sci Pract. 2023 Feb;63:102711. doi: 10.1016/j.msksp.2022.102711. Epub 2022 Dec 20.

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• Demangeot Y, Whiteley R, Gremeaux V, Degache F. The load borne by the Achilles tendon during exercise: A systematic review of normative values. Scand J Med Sci Sports. 2023 Feb;33(2):110-126. doi: 10.1111/sms.14242. Epub 2022 Nov 9.

  PMID: 36278501 BACKGROUND

• Crouzier M, Dandois F, Sarcher A, Bogaerts S, Scheys L, Vanwanseele B. External rotation of the foot position during plantarflexion increases non-uniform motions of the Achilles tendon. J Biomech. 2022 Aug;141:111232. doi: 10.1016/j.jbiomech.2022.111232. Epub 2022 Jul 22.

  PMID: 35905508 BACKGROUND

• Couppe C, Svensson RB, Josefsen CO, Kjeldgaard E, Magnusson SP. Ultrasound speckle tracking of Achilles tendon in individuals with unilateral tendinopathy: a pilot study. Eur J Appl Physiol. 2020 Mar;120(3):579-589. doi: 10.1007/s00421-020-04317-5. Epub 2020 Feb 14.

  PMID: 32060739 BACKGROUND

• Bogaerts S, De Brito Carvalho C, Scheys L, Desloovere K, D'hooge J, Maes F, Suetens P, Peers K. Evaluation of tissue displacement and regional strain in the Achilles tendon using quantitative high-frequency ultrasound. PLoS One. 2017 Jul 20;12(7):e0181364. doi: 10.1371/journal.pone.0181364. eCollection 2017.

  PMID: 28727745 BACKGROUND

• Baxter JR, Corrigan P, Hullfish TJ, O'Rourke P, Silbernagel KG. Exercise Progression to Incrementally Load the Achilles Tendon. Med Sci Sports Exerc. 2021 Jan;53(1):124-130. doi: 10.1249/MSS.0000000000002459.

  PMID: 32658037 BACKGROUND

• Arndt A, Bengtsson AS, Peolsson M, Thorstensson A, Movin T. Non-uniform displacement within the Achilles tendon during passive ankle joint motion. Knee Surg Sports Traumatol Arthrosc. 2012 Sep;20(9):1868-74. doi: 10.1007/s00167-011-1801-9. Epub 2011 Nov 27.

  PMID: 22120840 BACKGROUND

Central Study Contacts

Laura Lecompte, Msc

CONTACT

+32499263609; laura.lecompte@kuleuven.be

Marion Crouzier, PhD

CONTACT

+33 620045744; marion.crouzier@univ-nantes.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: PhD Student Biomechanics KU Leuven

Model Details: Two groups will follow the same exercise therapy program of 12 weeks with daily exercises for Achilles Tendinopathy where the intensity gradually increases over the weeks. One group will perform all exercises in a Neutral foot position whereas the other group will perform all exercises with the toes outwards rotated (toes-out foot position).

Study Record Dates

• First Submitted: May 5, 2026
• First Posted: June 3, 2026
• Study Start: February 19, 2026
• Primary Completion (Estimated): August 31, 2027
• Study Completion (Estimated): August 31, 2027
• Last Updated: June 3, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF
• Time Frame: Data will be available once published in a peer-reviewed manuscript online and this with no end-date.
• Access Criteria: People will be able to request data access through e-mail with explanation why it would be interesting for them to have the detailed individual data of (certain) outcome parameters.

Locations

BE (1)