Transcranial Direct Current Stimulation on Functionality and Pain in Individuals with Patellar Tendinopathy

Effectiveness of Transcranial Direct Current Stimulation on Functionality and Pain in Individuals with Patellar Tendinopathy: Randomized Clinical Trial

The aim of the present study is to investigate the effectiveness of transcranial direct current stimulation (tDCS) prior to a therapeutic eccentric exercise program on parameters related to pain and functionality in individuals with patellar tendinopathy. For this purpose, participants will be randomly divided into two groups: i) experimental group, receiving tDCS prior to a therapeutic exercise program; and ii) control group, receiving sham tDCS and a therapeutic exercise program. The interventions will last for 8 weeks. Additionally, four assessments will be conducted (baseline, week 4, week 8 and week 12). The variables studied are related to pain, functionality, muscle activity and strength, proprioception, and quality of life.

Study Overview

• Status: Recruiting
• Conditions: Patellar Tendinopathy
• Intervention / Treatment: Other: tDCS + Therapeutic eccentric exercise; Other: Sham tDCS + Therapeutic eccentric exercise

Detailed Description

Patellar tendinopathy is a painful condition affecting the anterior portion of the knee, commonly exacerbated by activities putting pressure on the patellofemoral joint. It remains a challenge for the healthcare system, not only due to its high prevalence, but also because of its high persistence and negative consequences. Although therapeutic exercise has been widely studied as a treatment strategy, eccentric exercise protocols, while effective, often require long application periods, which may affect treatment adherence. Additionally, eccentric exercise is pain-provoking and its therapeutic benefits for pain relief and functional improvement are controversial when used during the competitive season. More adaptable and personalized treatment strategies could enhance clinical outcomes and treatment adherence in patients with patellar tendinopathy. In this context, interventions combining exercise with other techniques have been proposed. However, existing evidence does not definitively determine the optimal approach for combining conservative treatment options to maximize benefits.

An emerging therapeutic approach combines Transcranial Direct Current Stimulation (tDCS) with therapeutic exercise protocols. tDCS involves the application of weak direct current to specific cortical areas, aiming to modulate brain excitability. This non-invasive method offers painless, selective, and focal stimulation with minimal side effects. Research increasingly supports the effectiveness of integrating tDCS with exercise for patellar tendinopathy, offering the potential to amplify exercise effects by modulating brain excitability. However, to date, no study has investigated the impact of tDCS combined with eccentric exercise on variables related to function and pain in patellar tendinopathy individuals.

Therefore, the aim of this study is to investigate the effectiveness of tDCS prior to a therapeutic eccentric exercise program on parameters related to pain and functionality in individuals with patellar tendinopathy.

This study is a randomized clinical trial in which two groups will participate, with different interventions: i) Experimental group: tDCS + Therapeutic eccentric exercise; and ii) Control group: Sham tDCS + Therapeutic eccentric exercise. The interventions will last for 8 weeks. Participants will be evaluated in four moments, at baseline, week 4, week 8 and week 12. The variables studied are related to pain, functionality, muscle strength and activity, proprioception, and quality of life.

• Study Type: Interventional
• Enrollment (Estimated): 42
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Marta Inglés, Dr; Phone Number: 963 98 38 55; Email: marta.ingles@uv.es
• Study Contact Backup: Name: Elena Muñoz-Gómez, Dr; Phone Number: 963 98 38 55; Email: elena.munoz-gomez@uv.es

Study Locations

• Spain
  • Valencia, Spain, 46022
    • Recruiting
    • Faculty of Physiotherapy, University of Valencia
    • Contact: Marta Inglés, PhD; Phone Number: (+34) 96 398 38 55

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age between 18 and 50 years.
• Diagnosis of patellar tendinopathy (VISA-P score of 80 or lower).
• Pain lasting more than 3 months.

Exclusion Criteria:

• Previous knee surgery.
• Corticosteroid injection in the previous 6 weeks.
• Systemic inflammatory, autoimmune, or rheumatic diseases.
• Cognitive or behavioural issues that hinder comprehension and adherence to the intervention.
• Any neurological disease.
• Neoplastic disease.
• Subjects presenting contraindications for tDCS (Thair et al., 2017), including: personal and family history of epilepsy, metallic implants in the head, implanted medication pump, pacemaker, recurrent headaches, skin conditions (psoriasis, eczema), or major head surgeries, pregnancy, heart diseases, and various medications (psychotropic or antihistamines).
• Subjects must not have undergone pharmacological treatment or knee physical rehabilitation programs for a period of 1 year.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental group; Participants will undergo an 8-week intervention of supervised eccentric exercise by a physiotherapist (3 sessions/week). During the first 4 weeks, real tDCS will be administered at a rate of 3 sessions per week (12 in total) as an adjunct to exercise . A direct current of 1.5 mA will be applied for 20 minutes to the primary motor cortex (M1) during each session of eccentric exercises. Additionally, all participants will perform the eccentric exercise program on the remaining weekdays at home unsupervised.	Other: tDCS + Therapeutic eccentric exercise; A direct current of 1.5 mA will be applied for 20 minutes to the primary motor cortex (M1) during each session of eccentric exercises.
Placebo Comparator: Sham group; Participants will undergo an 8-week intervention of supervised eccentric exercise by a physiotherapist (3 sessions/week). During the first 4 weeks, sham tDCS will be administered at a rate of 3 sessions per week (12 in total) as an adjunct to exercise. The current will be interrupted after 30 seconds. Additionally, all participants will perform the eccentric exercise program on the remaining weekdays at home unsupervised.	Other: Sham tDCS + Therapeutic eccentric exercise; The current will be interrupted after 30 seconds.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee functionality	The Victorian Institute of Sport Assessment-Patella (VISA-P) is a questionnaire to assess the severity of patellar tendinopathies. It consists of 8 items with a rating range from 0 to 100. The optimal state would correspond to a score of 100.	5 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain intensity	The single-leg squat pain provocation test is used to monitor the response to previous loading in athletes with patella tendinopathy. A visual analogue scale (VAS) will be used to determine pain intensity during the test. A score of 0 points indicates no pain and 10 points is the worst imaginable pain.	2 minutes
Health-related quality of life	The EuroQol 5 dimensions (EQ-5D) test is an instrument which evaluates the generic quality of life. Scores range from 0 (worst imaginable health state) to 100 (best imaginable health state).	2 minutes
Muscle strength	Maximum voluntary isometric contraction of the quadriceps, hamstrings, and hip abductors will be measured using a force sensor connected to the corresponding software (Chronojump Boscosystem). Higher values indicate greater muscle strength.	10 minutes
Electromyographic activity of lower limb muscles	Electromyographic activity during maximum voluntary isometric contraction of the rectus femoris, vastus lateralis, vastus medialis, biceps femoris, and semitendinosus muscles, using electromyography, will be registered.	5 minutes
Muscle flexibility	Knee joint range of motion will be measured in flexion and extension using a goniometer. Higher values indicate greater muscle flexibility.	5 minutes
Muscle tone	The biomechanical and viscoelastic properties of the muscle tissue will be evaluated using a non-invasive myometer, MyotonPRO (Myoton AS, Tallinn, Estonia). The patellar tendon, rectus femoris, vastus medialis, vastus lateralis, semitendinosus, and biceps femoris will be assessed. Higher values may indicate greater muscle stiffness or tone.	5 minutes
Proprioception	Proprioception will be assessed using the active knee repositioning test with an inclinometer. The difference between the target angle and the obtained angle will be registered. A smaller difference between the angles indicates better knee proprioception.	5 minutes
Patient global perception of change	The Patient Global Impression of Change Scale (PGIC) will be filled out. It consists of 7 points, with options ranging from "1=much better" to "7=much worse".	1 minute

Collaborators and Investigators

• Sponsor: University of Valencia
• Investigators: Principal Investigator: Marta Inglés, Dr, Univeristy of Valencia

Publications and helpful links

General Publications

• Bikson M, Grossman P, Thomas C, Zannou AL, Jiang J, Adnan T, Mourdoukoutas AP, Kronberg G, Truong D, Boggio P, Brunoni AR, Charvet L, Fregni F, Fritsch B, Gillick B, Hamilton RH, Hampstead BM, Jankord R, Kirton A, Knotkova H, Liebetanz D, Liu A, Loo C, Nitsche MA, Reis J, Richardson JD, Rotenberg A, Turkeltaub PE, Woods AJ. Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016. Brain Stimul. 2016 Sep-Oct;9(5):641-661. doi: 10.1016/j.brs.2016.06.004. Epub 2016 Jun 15.
• Hernandez-Sanchez S, Hidalgo MD, Gomez A. Cross-cultural adaptation of VISA-P score for patellar tendinopathy in Spanish population. J Orthop Sports Phys Ther. 2011 Aug;41(8):581-91. doi: 10.2519/jospt.2011.3613. Epub 2011 Jul 12.
• Cosca DD, Navazio F. Common problems in endurance athletes. Am Fam Physician. 2007 Jul 15;76(2):237-44.
• Peers KH, Lysens RJ. Patellar tendinopathy in athletes: current diagnostic and therapeutic recommendations. Sports Med. 2005;35(1):71-87. doi: 10.2165/00007256-200535010-00006.
• Vander Doelen T, Jelley W. Non-surgical treatment of patellar tendinopathy: A systematic review of randomized controlled trials. J Sci Med Sport. 2020 Feb;23(2):118-124. doi: 10.1016/j.jsams.2019.09.008. Epub 2019 Sep 13.
• Visnes H, Hoksrud A, Cook J, Bahr R. No effect of eccentric training on jumper's knee in volleyball players during the competitive season: a randomized clinical trial. Clin J Sport Med. 2005 Jul;15(4):227-34. doi: 10.1097/01.jsm.0000168073.82121.20.
• Liang Y, Jetton TL, Zimmerman EC, Najafi H, Berner DK, Matschinsky FM, Magnuson MA. Effects of glucose on insulin secretion, glucokinase activity, and transgene expression in transgenic mouse islets containing an upstream glucokinase promoter-human growth hormone fusion gene. Diabetes. 1994 Sep;43(9):1138-45. doi: 10.2337/diab.43.9.1138.
• Vairel EG. [Enzyme systems and the means to study them]. Biol Med (1971). 1973 Dec;2(2):123-39. No abstract available. French.
• McKittrick JE, Henrikson J, Iwasiuk GW. Indications for contralateral carotid endarterectomy: role of the noninvasive laboratory. Am J Surg. 1980 Aug;140(2):206-8. doi: 10.1016/0002-9610(80)90006-9.
• Dugois P, Amblard P, Gagnaire J, Imbert R. [Leg abscesses in stages after phlebosclerosus: complication of a septicemia of dental origin]. Bull Soc Fr Dermatol Syphiligr. 1968;75(4):518-20. No abstract available. French.
• Srivastava RA, Schonfeld G. Use of riboprobes for northern blotting analysis. Biotechniques. 1991 Nov;11(5):584, 586, 588.

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2024
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): July 1, 2027

Study Registration Dates

• First Submitted: December 7, 2024
• First Submitted That Met QC Criteria: December 7, 2024
• First Posted (Actual): December 11, 2024

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 25, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: transcranial direct current stimulation; therapeutic exercise; eccentric exercise; patellar tendinopathy
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Muscular Diseases; Wounds and Injuries; Tendon Injuries; Tendinopathy
• Other Study ID Numbers: 2023-FIS-3100133

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No