Anatomical accuracy of palpation-guided dry needling in lateral epicondylitis: An ultrasound-verified study of forearm extensor muscles

PurposeLateral epicondylitis (LE) is often associated with myofascial trigger points (MTrPs) in the forearm extensor muscles. Although dry needling (DN) is commonly performed using palpation-guided techniques without real-time imaging, its anatomical accuracy remains unclear. This study evaluated the accuracy of palpation-guided DN targeting the extensor digitorum communis (EDC), extensor carpi radialis brevis (ECRB), extensor carpi radialis longus (ECRL), and brachioradialis (BR) using ultrasound verification.MethodsThirty-nine patients with MRI-confirmed LE and active MTrPs underwent palpation-guided DN targeting the most symptomatic muscle identified by algometry. Ultrasound verified algometer position during target selection but did not guide needle insertion. An independent sonographer blinded to the intended target verified needle-tip location. Accuracy was compared using Fisher's exact test with Bonferroni correction.ResultsAccuracy was BR 10/10 (100%; 95% CI 69.2-100.0%), EDC 10/10 (100%; 69.2-100.0%), ECRB 7/9 (77.8%; 40.0-97.2%), and ECRL 1/10 (10%; 0.3-44.5%). After Bonferroni correction for six pairwise comparisons, ECRL accuracy was significantly lower than BR (adjusted p < 0.001), EDC (adjusted p < 0.001), and ECRB (adjusted p = 0.033). Most ECRL misplacements entered ECRB (7/9) or EDC (2/9). No identifiable neurovascular structure was penetrated during immediate ultrasound verification; procedural safety was not established.ConclusionAnatomical accuracy varied by target muscle in this small, single-operator study. ECRL showed particularly low observed accuracy. Ultrasound guidance may improve anatomical precision when targeting ECRL, but larger multi-operator studies are needed to confirm these findings and determine their clinical relevance.