Background Dry needling is therapeutic approach targeting myofascial trigger points. The application of dry needling into muscle strain is a controversial clinical topic. The application of dry needling under ultrasound guide may help to more precise therapeutic action of the needle. The current case report shows the long-term outcomes of a patient presenting with a muscle strain receiving ultrasound-guided dry needling combined with a low-load eccentric exercise program.

Methods An amateur mountain climber (male, 35 years old) presented with pain in the internal part of the right leg after an acute event 1 month ago during the practice of mountain climbing. The clinical history revealed pain and muscle weakness in the internal aspect of the right thigh. He also reported the presence of a hematoma from the groin until the internal aspect of the knee. The day of appointment the patient reported local pain, he felt a rope spot and muscle weakness during contraction of the right leg. No evidence of hematoma was observed. Clinical examination revealed an exquisite tender spot in the gracilis muscle on palpation. Ultrasound examination confirmed the presence of a strain on the middle portion of the gracilis muscle. The patient received a single session of ultrasound-guided dry needling in to the muscle combined with a low-load eccentric exercise program. Outcomes including pain intensity (NPRS, 0–10), self-perceived muscle weakness on a 7-point Likert Scale (0–7), and muscle strain size evaluated with ultrasound were assessed at baseline, and 1 week, 1 month 3 months and 12 months follow-up after the intervention.

Results At baseline, pain intensity with contraction was 6/10, muscle weakness was rated as 5/7 and the ultrasound examination revealed a strain injury of 0.27 × 0.60 cm. After the application of a single session of dry needling, pain intensity was 2/10, muscle weakness was rated 2/7 and the strain was 0.27 × 0.26 cm on the ultrasound imaging. The patient was asked for doing low-load eccentric exercises of the adductor musculature for 4 weeks. At consecutive appointments, the patient reported no pain and 90%–100% recovery on muscle weakness. Ultrasound examination revealed no muscle strain from 1 week after dry needling intervention. These outcomes were maintained during all follow-ups.

Conclusions Application of ultrasound-guided dry needling combined with low-load eccentric exercises was effective at long-term for muscle strain injury in an amateur climber.