Purpose: This study aimed to identify an effective hamstring exercise method that selectively activates the medial and lateral hamstrings. Methods: Five healthy adults were enrolled in this cross-sectional pilot laboratory study. Surface electromyography was recorded from the semitendinosus and biceps femoris of the dominant limb during prone isometric knee flexion at 90°, with resistance applied at 0° (neutral), 45° (resistance applied from lateral to medial), and −45° (resistance applied from medial to lateral) in randomized order. Three 5-second maximal trials per direction were performed with 30-second rest intervals. Isometric knee flexion strength was measured using a Smart KEMA system (Koreatech Co., Ltd.), and the outcomes were descriptively compared. Results: The participants (three females and two males; 32.4±4.5 years) demonstrated the highest mean semitendinosus and biceps femoris activity at 0° (154.7±24.1 μ V and 100.2±25.1 μ V, respectively) and the lowest at 45° (105.3±5.6 μ V and 76.9±4.4 μ V) and −45° (129.3±12.1 μ V and 64.7±19.0 μ V). The medial-to-lateral activity ratio was highest at −45° (2.2±0.6), compared with 0° (1.6±0.3) and 45° (1.4±0.1). Strength was the greatest at 0° (7.5±0.5) compared with 45° (6.4±1.3) and −45° (5.5±1.3). Conclusion In this pilot study, the medial-to-lateral electromyographic ratio tended to be highest when resistance was applied at −45°, suggesting greater medial hamstring recruitment under this condition. These descriptive findings are preliminary and should be confirmed in adequately powered studies. Modifying the direction of resistance may be a feasible strategy to bias medial (−45°) or lateral (45°) hamstring recruitment depending on rehabilitation goals.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Purpose: This study aimed to evaluate the predictive value of apparent diffusion coefficient (ADC) values from magnetic resonance imaging (MRI) in assessing pathologic response to neoadjuvant chemotherapy (NAC) in patients with muscle-invasive bladder cancer (MIBC) and the optimal cutoff value of ADC for predicting NAC response. Materials and Methods: Among 582 patients who underwent radical cystectomy between December 2011 and December 2024, we included 146 patients who received preoperative NAC and pretreatment MRI. Pathologic response was determined based on the surgical pathology results: patients with pathologic stage >pT2 and/or presence of nodal involvement (N+) were classified as nonresponders, while those with ≤pT2 and no nodal involvement (N0) were classified as responders. MRI-derived ADC values were compared between the 2 groups. The receiver operating characteristic (ROC) curve was used to determine the optimal cutoff value for predicting NAC response. Multivariate logistic regression analysis using preoperative parameter was performed and Kaplan-Meier survival analysis were utilized to assess overall survival (OS) and cancer-specific survival (CSS) according to NAC response. Results: Among the 146 patients, 90 (61.6%) were classified as responders, 56 (38.4%) were nonresponders. The mean ADC value was significantly higher in responders (1,100.35±249.12 mm2/sec) than in nonresponders (763.95±118.97 mm2/sec, p<0.001). ROC analysis demonstrated an area under the curve of 0.69, with an optimal cutoff value of 845.0 mm2/sec. Multivariate logistic regression identified ADC value as an independent predictor of NAC response (odds ratio, 1.025; 95% confidence interval, 1.006–1.043; p=0.008). During median follow-up 30.3 months, Kaplan-Meier analysis revealed that responders had significantly better 5-year OS (80.8% vs. 45.9%) and 5-year CSS (92.6% vs. 54.5%), with log-rank test p<0.001. Conclusion MRI-derived ADC values are a reliable imaging biomarker for predicting pathologic response to NAC in MIBC. Further validation in large-scale prospective studies is required to confirm these findings.

Objective: Primary frozen shoulder causes significant pain and progressively restricts shoulder movements. Diagnosis is made clinically based on patient history and physical examination. Management is mainly non-invasive owing to its self-limiting clinical course. However, clinical practice guidelines for frozen shoulder have not yet been developed in Korea. The developed guidelines aim to provide evidence-based recommendations for the diagnosis and treatment of frozen shoulder. Methods: A guideline development committee reviewed the literature from four databases (PubMed, Embase, Cochrane Library, and KMbase). Using the Population, Intervention, Comparator, and Outcome (PICO) framework, the committee formulated two backgrounds and 16 key questions to address common clinical concerns. Recommendations were made using the Grading of Recommendations, Assessment, Development, and Evaluation framework. Results: Diabetes, thyroid disease, and dyslipidemia significantly increase the risk of developing a frozen shoulder. Although frozen shoulder is often self-limiting, some patients may experience long-term functional disabilities. Ultrasound and magnetic resonance imaging should be used as adjunctive tools alongside clinical diagnosis, and rather than as independent diagnostic methods. Noninvasive approaches, such as medications, physical modalities, exercises, electrical stimulation, and manual therapy, may reduce pain and improve shoulder function. Other noninvasive interventions have limited evidence, and their application should be based on clinical judgment. Intra-articular steroid injections are recommended for treatment, and physiotherapy or hydrodilation with steroid injections can also be beneficial. Conclusion These guidelines provide evidence-based recommendations for diagnosing and treating primary frozen shoulder.