Background: Hypermobility of the ulnar nerve from the cubital tunnel reportedly occurs in healthy people without symptoms of ulnar neuropathy. However, the occurrence rate in athletes is unknown. We examined the occurrence rate of ulnar nerve hypermobility using ultrasonography, symptoms, and physical findings in athletes and compared the results of four types of sports. Methods: Medical charts of college athletes competing in baseball, rugby, soccer, and long-distance running between March and November 2018 were retrospectively examined. Dynamic evaluation of the ulnar nerve was performed using ultrasonography and categorized as Types N, S, and D respectively, indicating normal position, subluxation, and dislocation. Subjective and objective findings were evaluated. Results: The present study included 246 male athletes (mean age, 19.7 years; 492 elbows) including 46% Type D, 29.8% Type S, and 24.2% Type N. Subjective findings showed pain and dysesthesia in 9% and 4.5% of participants, respectively, whereas objective findings showed Tinel sign in 6%, nerve tension test in 1.3%, Froment’s sign in 0.5%, and weakness of strength of opponens digiti minimi muscle in 8% of patients with Types D and S. Conclusions: There was a high-frequency hypermobility of the ulnar nerve from the cubital tunnel with or without subjective and objective findings in college athletes.

Objectives: Hamstring strain injuries are common in elite athletes and affect return-to-sport timelines. Although magnetic resonance imaging (MRI) is the gold-standard method for assessing injury severity, ultrasonography (US) is a more accessible and cost-effective alternative. This study aimed to evaluate the agreement between US and MRI in the diagnosis of hamstring injuries and their prognostic value in predicting recovery. Methods: This retrospective study included elite athletes who sustained acute first-time hamstring strains and underwent both MRI and US within five days after injury. The injuries were classified according to location (muscle belly, musculotendinous junction, or tendon) and severity (modified Peetron’s classification). The agreement between the imaging findings and return-to-sports timelines was analyzed. Results: US demonstrated a 70% agreement with MRI in identifying injury locations, showing the highest concordance for muscle belly injuries (90%), followed by musculotendinous junction (80%) injuries, but a lower accuracy for tendon injuries (60%). Recovery times differed significantly by location and severity (p < 0.01), with tendon grade 3 injuries requiring the longest recovery (383 days) and muscle belly injuries requiring the shortest recovery (16 days). Musculotendinous junction grade 2, tendon grade 1, and tendon grade 2 injuries had similar recovery durations (57–65 days). Conclusions: High-resolution US is a reliable diagnostic tool for muscle belly and musculotendinous junction injuries. However, MRI remains essential for high-grade tendon injuries. US serves as the first-line imaging modality, with MRI reserved for cases that require a detailed prognostic assessment. These findings provide guidance for optimizing imaging strategies for hamstring injury management.

Background/Objectives: Hamstring strain injuries are common in elite athletes and affect return-to-sport timeline. Although magnetic resonance imaging (MRI) is the gold standard for assessing injury severity, ultrasonography (US) is a more accessible and cost-effective alternative. This study aimed to evaluate the agreement between US and MRI in the diagnosis of hamstring injuries and their prognostic value in predicting recovery. Methods: This retrospective study included elite athletes with acute first-time hamstring strains who underwent both MRI and US within five days after injury. The injuries were classified according to location (muscle belly, musculotendi-nous junction, or tendon) and severity (modified Peetrons classification). The agree-ment between imaging findings and return-to-sport timelines was analyzed. Results: US demonstrated 70% agreement with MRI in identifying injury locations, with the highest concordance for muscle belly (90%) and musculotendinous junction (80%) in-juries but lower accuracy for tendons (60%). Recovery times differed significantly by location and severity (p < 0.01), with tendon grade 3 injuries requiring the longest re-covery (383 days), while muscle belly injuries had the shortest recovery (16 days). Musculotendinous junction grade 2, tendon grade 1, and tendon grade 2 injuries had similar recovery durations (57–65 days). Conclusions: High-resolution US is a reliable diagnostic tool for muscle belly and musculotendinous junction injuries; however, MRI remains essential for high-grade tendon injuries. US serves as a first-line imaging mo-dality, with MRI reserved for cases that require a detailed prognostic assessment. These findings provide guidance for optimizing imaging strategies for hamstring inju-ry management.

Background: Chronic insertional rupture of the tibialis anterior tendon is uncommon and presents substantial reconstructive challenges, particularly when associated with large tendon defects and distal degeneration. Primary repair is often not feasible in such cases, and conventional reconstructive techniques frequently require prolonged postoperative immobilization, delaying functional recovery. Case presentation: We report a case of chronic insertional tibialis anterior tendon rupture in a 64-year-old Japanese male recreational weightlifter, treated with reconstruction using an ipsilateral semitendinosus autograft. A modified side-locking loop suture technique was employed for proximal fixation, and anatomical distal fixation was achieved using multiple all-suture anchors. This construct was designed to provide sufficient initial biomechanical stability to permit early postoperative rehabilitation. Postoperatively, the ankle was immobilized for 2 weeks, followed by initiation of active range of motion exercises and progressive weight-bearing. At the 2-year follow-up, the patient demonstrated complete pain relief, normal gait, and excellent functional recovery. Isokinetic testing revealed dorsiflexion strength exceeding 95% of the contralateral side, and magnetic resonance imaging confirmed continuity and favorable remodeling of the reconstructed tendon. Conclusions: This case demonstrates that reconstruction of chronic insertional tibialis anterior tendon rupture using a semitendinosus autograft combined with a modified side-locking loop suture and multi-anchor fixation can provide sufficient stability to allow early functional rehabilitation. This approach may represent a viable treatment option for active patients with large tendon defects.