Entrapment of the radial nerve at the arcade of Frohse could contribute to symptoms in patients with lateral epicondylalgia or radial tunnel syndrome. Our aim was to determine the validity of applying percutaneous electrolysis, targeting the supinator muscle at the Frohse’s arcade with ultrasound imaging and in a Thiel-embalmed cadaver model (not ultrasound-guiding). Percutaneous electrolysis targeting the supinator muscle was conducted in five healthy volunteers (ultrasound study) and three Thiel-embalmed cadaver forearms. Two approaches, one with the forearm supinated and other with the forearm pronated were conducted. The needle was inserted until the tip reached the interphase of both bellies of the supinator muscle. Accurate needle penetration of the supinator muscle was observed in 100% in both US-imaging and cadaveric studies. No neurovascular bundle of the radial-nerve deep branch was pierced in any insertion. The distance from the tip of the needle to the neurovascular bundle was 15.3 ± 0.6 mm with the forearm supinated, and 11.2 ± 0.6 mm with the forearm pronated. The results of the current study support that percutaneous electrolysis can properly target the supinator muscle with either the forearm in supination or in pronation. In fact, penetration of the neurovascular bundle was not observed in any approach when percutaneous needling electrolysis was performed by an experienced clinician.

We aimed to investigate clinical and ultrasound signs of shoulder overuse injuries in professional bullfighters; side-to-side differences (dominant vs. non-dominant); and to determine potential differences according to bullfighters’ categories. An observational cross-sectional study was conducted. Thirty professional and active bullfighters were assessed. A bilateral ultrasound assessment of the subacromial bursa, long biceps head tendon (LHBT), and rotator cuff was performed to determine the presence of bursitis, subluxation, partial or total tendon rupture, tenosynovitis, or calcification. Supraspinatus tendon thickness was measured. Finally, a battery of clinical orthopedic tests (Yergason, Jobe, infraspinatus, Gerber, and bursa tests) were also performed. Most identified ultrasound findings were located in the dominant side, being the presence of bursitis (n = 9; 30%), LHBT tenosynovitis (n = 8; 26.7%), and subscapularis tendon calcification (n = 5; 16.7%) the most prevalent. No side-to-side or between-categories differences were found for supraspinatus tendon thickness (all, p > 0.05). The most frequent positive signs were the infraspinatus test (40.0%), Gerber lift-off test (33.3%), and bursitis, Jobe, and Yergason tests (all, 26.7%). Ultrasound signs were commonly found at LHBT, subacromial bursa, and rotator cuff in professional bullfighters without difference between categories and sides. No side-to-side or between-categories differences were found. Positive clinical test signs suggestive of bursitis, LHBT, and rotator cuff tendinopathy were frequently observed.

Achilles tendon tendinopathy (AT) is a musculoskeletal condition characterized by pain in the Achilles tendon and impaired physical performance or sport activities. AT is difficult to treat, and the results are variable. Preliminary evidence suggests a positive effect for pain of percutaneous electrolysis in patients with tendinopathy. Our aim was to determine the validity and safety of a percutaneous electrolysis approach targeting the interphase between the Achilles tendon and the Kager’s fat with ultrasound imaging in both healthy individuals and on a fresh cadaver model (not ultrasound guiding). A needle was inserted from the medial to the lateral side under the body of the Achilles tendon, just between the tendon and the Kager’s triangle, about 5 cm from the insertion of tendon in the calcaneus in 10 healthy volunteers (ultrasound study) and 10 fresh cadaver legs. An accurate needle penetration of the interphase was observed in 100% of the approaches, in both human and cadaveric models. No neurovascular bundle of the sural nerve was pierced in any insertion. The distance from the tip of the needle to the sural nerve was 5.28 ± 0.7 mms in the cadavers and 4.95 ± 0.68 mms in the volunteer subjects, measured in both cases at a distance of 5 cm from the insertion of the Achilles tendon. The results of the current study support that percutaneous electrolysis can be safely performed at the Kager’s fat–Achilles tendon interphase if it is US guided. In fact, penetration of the sural nerve was not observed in any needle approach when percutaneous needling electrolysis was performed by an experienced clinician. Future studies investigating the clinical effectiveness of the proposed intervention are needed.

Distal biceps brachii tendinopathy is a musculoskeletal pain condition—comprising chronic intrasubstance degeneration with alterations of the tendon structure—that is difficult to treat. Preliminary evidence suggests a positive effect for pain and related disability of percutaneous electrolysis treatment in patients with tendinopathy. Ultrasound is an excellent diagnostic tool to identify tendon injuries, such as tendinopathy, and to guide treatment approaches. Different approaches using ultrasound evaluation of the biceps tendon have been described. Our aim was to determine the validity and safety of a percutaneous electrolysis approach, targeting insertion of the distal tendon of biceps brachii, in both human (ultrasound-guided) and Thiel-embalmed cadaver (not ultrasound-guided) models. There were two approaches evaluated: an anterior approach with the elbow in extension and the forearm in supination and a posterior approach with the elbow in flexion and the forearm in pronation. A needle was inserted following the tendon up to its insertion into the radial tuberosity. The anterior approach, both in cadaveric study and US-guided intervention, revealed a close relationship between the distal biceps tendon and the brachial artery. The mean distance of the depth of the biceps tendon distal to the brachial artery was 0.21 ± 0.021 cm in the cadavers and 0.51 ± 0.024 cm in subjects. It was also found that the anterior approach has a potential technical difficulty due to the anatomical location of the brachial artery. With the posterior approach, it was possible to safely identify the tendon insertion and the needle approach, since no important vascular and nervous structures were visualized in the window of insertion of the needle. The clinician rated the posterior approach as low difficulty in all subjects. Current results would support a posterior approach with US guidance as a safe approach for applying the percutaneous electrolysis technique for insertional tendinopathies of the distal biceps brachii tendon. The current study did not assess the effectiveness of the proposed intervention; accordingly, future studies investigating the clinical effectiveness of the proposed intervention are needed.

This study aimed to evaluate the inter-examiner reliability of shear wave elastography (SWE) for measuring cervical multifidus (CM) muscle stiffness in asymptomatic controls and patients with chronic neck pain. A longitudinal observational study was conducted to assess the diagnostic accuracy of a procedure. SWE images, following a detailed procedure previously tested, were acquired by two examiners (one novice and one experienced) to calculate the shear wave speed (SWS) and Young’s modulus. The painful side was examined for the experimental cases while the side examined in the control group was selected randomly. Data analyses calculated the intra-class correlation coefficients (ICCs), absolute errors between examiners, standard errors of measurement, and minimal detectable changes. A total of 125 participants were analyzed (n = 54 controls and n = 71 cases). The Young’s modulus and SWS measurements obtained by both examiners were comparable within the asymptomatic group (both, p > 0.05) and the chronic neck pain group (both, p > 0.05). Nonetheless, a notable distinction was observed in the absolute error between examiners for shear wave speed measurements among patients with neck pain, where a significant difference was registered (p = 0.045), pointing to a sensitivity in measurement consistency affected by the presence of chronic neck pain. ICCs demonstrated moderate-to-good reliability across both groups, with ICC values for asymptomatic individuals reported as >0.8. Among the chronic neck pain patients, ICC values were slightly lower (>0.780). The study revealed moderate-to-good consistency, highlighting the practicality and generalizability of SWE.

Objectives: The dry needling of the piriformis muscle (especially in the medial region) is a challenging procedure since there is a high risk of accidentally puncturing the sciatic nerve. This study aimed to explain the variance of the deep limit of the piriformis based on anthropometric and demographic predictors potentially associated with it by exploring if clinicians can select the optimal needle length needed accurately to avoid accidental punctures of the sciatic nerve during palpation-guided dry needling interventions. Methods: An observational study was conducted that included fifty-six patients with piriformis muscle syndrome. We recorded the skin-to-sciatic nerve distance at the location with greatest risk of accidental sciatic puncture (assessed with ultrasound imaging) and demographic (e.g., age, gender, height, weight and body mass index—BMI) and anthropometric (hip circumference) variables. Results: Thirty-four males (n = 34) and twenty-two females (n = 22) were analyzed. Although men presented a significantly greater hip circumference than women (p = 0.007), no skin-to-sciatic nerve distance differences were observed (p > 0.05). Correlation analyses revealed that the sciatic nerve’s depth is associated with weight, BMI and hip perimeter (all, p < 0.01) but not with age or height (p > 0.05). Due to shared variance and multicollinearity, the hip circumference was the only predictor included in the regression model, explaining 37.9% of the piriformis muscle’s deeper fascia depth variance (R² Adjusted = 0.379). Conclusions: Although the use of landmarks and measuring the hip perimeter may result in greater dry needling accuracy and a lower risk of adverse events derived from accidental sciatic nerve puncture, ultrasound guidance is encouraged as is the safest method for avoiding serious adverse events.