ISOMETRIC CONTRACTION-BASED PAIN MODULATION VERSUS ECCENTRIC STRENGTHENING IN TREATING ACHILLES TENDINOPATHY: A RANDOMIZED CLINICAL TRIAL
DOI:
https://doi.org/10.71000/bryh8q89Keywords:
Achilles Tendinopathy, Algometry, Eccentric Exercise, Exercise Therapy, Isometric Contraction, Pain Measurement, Tendinopathy RehabilitationAbstract
Background: Achilles tendinopathy is a degenerative condition of the Achilles tendon that leads to pain, impaired function, and reduced quality of life. Exercise-based rehabilitation remains the cornerstone of management, with isometric and eccentric protocols being widely prescribed. Although both approaches are commonly used, evidence directly comparing their effectiveness remains limited, particularly in controlled clinical trials. Establishing the superior exercise protocol is essential for developing evidence-based rehabilitation strategies to optimize tendon recovery and functional outcomes.
Objective: The objective of this study was to evaluate and compare the effectiveness of isometric contraction-based pain modulation and eccentric strengthening in the rehabilitation of patients with Achilles tendinopathy.
Methods: A single-blinded randomized controlled trial was conducted at a tertiary care hospital over six months, enrolling 42 patients (mean age 46.8 ± 6.6 years) diagnosed with Achilles tendinopathy confirmed by MRI. Participants were randomly assigned into two groups (n = 21 each). Group A performed an isometric contraction-based protocol, while Group B underwent Alfredson’s eccentric strengthening program. Both groups participated in six sessions per week for 12 weeks. Outcome measures included the Numeric Pain Rating Scale (NPRS), Victorian Institute of Sport Assessment–Achilles (VISA-A), and pressure algometry. Assessments were recorded at baseline, 6 weeks, and 12 weeks.
Results: Both groups showed significant improvement over time; however, Group B demonstrated superior outcomes. Post-treatment median NPRS was 2.00 (IQR: 3.00–1.50) in Group B versus 5.00 (IQR: 5.00–4.00) in Group A (p = 0.000, rr = 0.876). VISA-A scores improved to 89.00 (IQR: 91.00–87.00) in Group B compared to 76.00 (IQR: 78.00–72.00) in Group A (p = 0.000, rr = 0.857). Pressure algometry increased to 6.00 (IQR: 7.00–6.00) in Group B versus 4.00 (IQR: 5.00–4.00) in Group A (p = 0.000, rr = 0.886).
Conclusion: Both isometric and eccentric loading improved pain and function in Achilles tendinopathy, but eccentric strengthening provided greater pain reduction, enhanced functional recovery, and higher pressure pain thresholds. These findings support the preferential use of eccentric loading in tendon rehabilitation.
References
Charles R, Fang L, Zhu R, Wang J. The effectiveness of shockwave therapy on patellar tendinopathy, Achilles tendinopathy, and plantar fasciitis: a systematic review and meta-analysis. Front Immunol. 2023;14:1193835.
Li M, Zhang T, Zhu J, Li Y, Chen W, Xie Y, et al. Risk factors of perioperative complications and management with enhanced recovery after primary surgery in women with epithelial ovarian carcinoma in a single center. Oncol Lett. 2022;23(5):155.
de Vos RJ, van der Vlist AC, Zwerver J, Meuffels DE, Smithuis F, van Ingen R, et al. Dutch multidisciplinary guideline on Achilles tendinopathy. Br J Sports Med. 2021;55(20):1125-34.
Malliaras P. Physiotherapy management of Achilles tendinopathy. J Physiother. 2022;68(4):221-37.
Silbernagel KG, Hanlon S, Sprague A. Current Clinical Concepts: Conservative Management of Achilles Tendinopathy. J Athl Train. 2020;55(5):438-47.
Tarantino D, Mottola R, Resta G, Gnasso R, Palermi S, Corrado B, et al. Achilles Tendinopathy Pathogenesis and Management: A Narrative Review. Int J Environ Res Public Health. 2023;20(17).
van der Vlist AC, Winters M, Weir A, Ardern CL, Welton NJ, Caldwell DM, et al. Which treatment is most effective for patients with Achilles tendinopathy? A living systematic review with network meta-analysis of 29 randomised controlled trials. Br J Sports Med. 2021;55(5):249-56.
Wang Y, Zhou H, Nie Z, Cui S. Prevalence of Achilles tendinopathy in physical exercise: a systematic review and meta-analysis. Sports Medicine and Health Science. 2022;4(3):152-9.
von Rickenbach KJ, Borgstrom H, Tenforde A, Borg-Stein J, McInnis KC. Achilles Tendinopathy: Evaluation, Rehabilitation, and Prevention. Curr Sports Med Rep. 2021;20(6):327-34.
Javed S, Amjad MR, Mehmood A, Asghar HMU, Javaid M, Avaid A. Prevalence of Achilles Tendinopathy in Female Nurses in Lahore-Pakistan. Pakistan Journal of Medical & Health Sciences. 2022;16(07):88-.
Ko VM, Cao M, Qiu J, Fong IC, Fu SC, Yung PS, et al. Comparative short-term effectiveness of non-surgical treatments for insertional Achilles tendinopathy: a systematic review and network meta-analysis. BMC Musculoskelet Disord. 2023;24(1):102.
Mansur NSB, Matsunaga FT, Carrazzone OL, Schiefer Dos Santos B, Nunes CG, Aoyama BT, et al. Shockwave Therapy Plus Eccentric Exercises Versus Isolated Eccentric Exercises for Achilles Insertional Tendinopathy: A Double-Blinded Randomized Clinical Trial. J Bone Joint Surg Am. 2021;103(14):1295-302.
Millar NL, Silbernagel KG, Thorborg K, Kirwan PD, Galatz LM, Abrams GD, et al. Tendinopathy. Nat Rev Dis Primers. 2021;7(1):1.
Phisitkul P, Mansur NSB, Netto CC. Failed Surgery for Achilles Tendinopathy. Foot Ankle Clin. 2022;27(2):431-55.
Schuppisser MV, Mondini Trissino da Lodi C, Albanese J, Candrian C, Filardo G. Achilles tendinopathy research has a gender data gap: A systematic review and meta-analysis. Knee Surg Sports Traumatol Arthrosc. 2024;32(10):2538-50.
Thompson JM, Nguyen K, Ahluwalia J, Casciato D, Tewilliager T, So E, et al. Surgical Takedown Approaches to Insertional Achilles Tendinopathy: A Systematic Review. J Foot Ankle Surg. 2021;60(6):1217-21.
Agyeman-Prempeh NO, Maas H, Burchell GL, Millar NL, Moen MH, Smit TH. Treatment options for Achilles tendinopathy: a scoping review of preclinical studies. PeerJ. 2025;13:e18143.
Amlang MH, Luttenberger M, Rammelt S. [Surgical treatment of calcifying insertional Achilles tendinopathy via a lateral approach]. Oper Orthop Traumatol. 2022;34(6):392-404.
Dyrek P, Tsitsilianos N, McInnis KC, Tenforde AS, Borg-Stein J. Staying in the Game: Interventions for Managing Achilles Tendinopathy in the In-Season Athlete. Curr Sports Med Rep. 2024;23(6):237-44.
Savva C, Karagiannis C, Korakakis V, Efstathiou M. The analgesic effect of joint mobilization and manipulation in tendinopathy: a narrative review. J Man Manip Ther. 2021;29(5):276-87.
Scott AT, Long CS, Jaramillo TJ, Lara DL, Marois AJ, Juneja P. Review of Achilles Tendon Reattachment Using Double-Row Knotted and Knotless Techniques in the Management of Insertional Achilles Tendinopathy. J Foot Ankle Surg. 2022;61(5):927-31.
Gatz M, Betsch M, Dirrichs T, Schrading S, Tingart M, Michalik R, et al. Eccentric and Isometric Exercises in Achilles Tendinopathy Evaluated by the VISA-A Score and Shear Wave Elastography. Sports Health. 2020;12(4):373-81.
Van der Vlist AC, van Veldhoven PL, van Oosterom RF, Verhaar JA, de Vos RJ. Isometric exercises do not provide immediate pain relief in Achilles tendinopathy: A quasi‐randomized clinical trial. Scandinavian Journal of Medicine & Science in Sports. 2020;30(9):1712-21.
Clifford C, Challoumas D, Paul L, Syme G, Millar NL. Effectiveness of isometric exercise in the management of tendinopathy: a systematic review and meta-analysis of randomised trials. BMJ open sport & exercise medicine. 2020;6(1).
Downloads
Published
Issue
Section
License
Copyright (c) 2025 Ayesha Siddiqua, Sahar Aslam, Nawal Fatima, Meenal Arshad, Zinnia Akram, Fatima Sabir, Nimra Zaheer (Author)
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
