This completed clinical study evaluated whether a structured eccentric training program reduced pain and improved hand and wrist function in adults with medically diagnosed de Quervain's tendinopathy whose symptoms had persisted despite previous conservative treatment.

The main questions addressed were:

• Did eccentric training reduce pain intensity and the extent of pain distribution in participants with de Quervain's tendinopathy?
• Did eccentric training improve hand and wrist function in daily activities and work-related tasks? Participants received a structured eccentric exercise program for 8 weeks. After instruction by a physiotherapist, they performed the exercises at home 1 to 5 times daily, at least 5 days per week, and adherence was monitored during supervised visits. Participants also recorded exercise sessions in a calendar.

Assessments were conducted at baseline and at week 8 and included pain evaluation, pain-area mapping, and validated hand and wrist function questionnaires. For participants with insufficient adherence or incomplete recovery, the intervention period was extended to 12 weeks, with an additional assessment at week 12. Post-treatment follow-up was specified in the study protocol at weeks 10 and 12 and approximately 6 months after treatment initiation.

De Quervain's tendinopathy is a painful disorder of the first dorsal extensor compartment of the wrist that can impair thumb motion, grip-related activities, and overall hand function. The study was based on the rationale that de Quervain's tendinopathy is increasingly regarded as a degenerative rather than primarily inflammatory condition, and that eccentric loading may therefore represent a relevant conservative treatment approach. The purpose of the study was to evaluate the clinical effectiveness of a structured eccentric training program in adults with persistent de Quervain's tendinopathy after unsuccessful prior conservative management.

Eligible participants were adults with a medical diagnosis of de Quervain's tendinopathy who reported pain in the region of the radial styloid, had a positive stepped Finkelstein test, and did not report radiating arm pain during testing. Participants had a history of at least one unsuccessful conservative treatment before enrolment. Exclusion criteria included expected surgical intervention, concurrent alternative treatment during the exercise program, unclear diagnosis, inability to comply with the exercise instructions or follow-up schedule, participation in another similar study, and minor age.

This was a single-arm interventional study in which all enrolled participants received the same structured eccentric training program. After initial instruction, participants performed the exercise program at home for 8 weeks, with 1 to 5 sessions daily on at least 5 days per week. The protocol described progressive exercise stages across the intervention period, with more frequent supervision during the first 4 weeks and weekly supervision thereafter. Participants were also instructed to modify daily activities, reduce use of the painful hand, increase reliance on the unaffected side, when possible, incorporate rest periods during repetitive hand activity, and document exercise completion in a calendar.

Outcome assessment focused on pain and function. Data collection included pain intensity measured with the Numeric Pain Rating Scale, upper-limb disability measured with the Quick Disabilities of the Arm, Shoulder and Hand questionnaire, wrist-specific pain and function measured with the Patient-Rated Wrist Evaluation, and pain distribution recorded using predefined hand regions. The manuscript also described clinical evaluation of range of motion and muscle strength, while the research plan outlined baseline anamnesis, physical examination, and diagnostic confirmation procedures. Assessments were performed at baseline and at week 8, and for those whose program was prolonged, also at week 12.

According to the manuscript, some participants required extension of the intervention to 12 weeks because the expected improvement had not occurred by week 8 in the context of insufficient exercise regularity. The protocol further specified post-treatment follow-up contacts at weeks 10 and 12 and approximately 6 months after treatment initiation, with additional in-person reassessment if recurrent pain was reported. In this retrospective registry description, these follow-up procedures are described as protocol-specified elements in order to avoid overstating information not fully detailed in the manuscript results section.

Inclusion Criteria:

• Adult patients aged 18 years or older.
• Medical diagnosis of de Quervain's tendinopathy.
• Increased pain in the area of the radial styloid process.
• Positive stepped Finkelstein test.
• No pain radiating to the arm during the stepped Finkelstein test.
• History of at least one unsuccessful conservative treatment.
• No other treatment received during the eccentric training intervention.

Exclusion Criteria:

• Expected surgical intervention or concurrent alternative therapies.