The Associated Risk Factors for Entrapment Neuropathy in the Upper Extremity: The Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS)

Purpose: Although carpal tunnel syndrome (CTS) and cubital tunnel syndrome (CuTS) are the most common neuropathies in the upper extremities, there have been few studies describing the etiology and associated factors in the general population. The purpose of this study was to investigate and clarify the etiology and associated factors for CTS and CuTS in the Japanese general population. Methods: A total of 1875 participants, who participated in health checkups conducted in rural areas in Japan in 2010, were enrolled. The prevalence of CTS and CuTS was investigated. Logistic regression models were performed to examine the relationship between CTS and CuTS and correlated factors such as occupational status, smoking and alcohol preferences, and medical characteristics. Results: The overall prevalence of CTS and CuTS was 2.0% and 2.2%, respectively. With regards to CTS, female subjects showed 7.33-times higher risk of CTS compared with male subjects. In addition, hypertension was also at high risk of CTS (5.56-times higher in borderline and 4.55-times higher in definite hypertension compared with normal blood pressure). However, there were no significant associations between CuTS and age, gender, occupation, smoking and alcohol preferences, or metabolic factors. Conclusions: CTS was associated with female gender and hypertension, whereas there was no obvious risk factor contributing to the onset of CuTS.

The Prevalence and Characteristics of Thoracic Outlet Syndrome in High School Baseball Players

Thoracic outlet syndrome (TOS) is one of the common neurovascular disorders of the upper extremities, and the compression or traction of the brachial plexus is the main pathology. We hypothesized that baseball players are more likely to be affected by TOS compared with other overhead-throwing athletes because of strenuous use of their throwing arm. The purpose of this study was to investigate the prevalence and clinical characteristics of TOS in high school baseball players. One thousand two hundred eighty-eight high school baseball players were included in this study. The prevalence of symptomatic TOS and its association to disorders of the upper extremities were investigated. The prevalence of symptomatic TOS was 32.8%. Age- and position-adjusted logistic regression analysis revealed that subjects with symptomatic TOS were at significantly higher risk of shoulder and/or elbow pain (odds ratio [OR]: 1.96, 95% confidence interval [CI]: 1.50 - 2.58) and a higher recurrence rate of shoulder and/or elbow pain during the previous season (OR: 2.38, 95% CI: 1.87 - 3.04). As for physical findings, subjects with symptomatic TOS were also at significantly higher risk of MUCL tenderness (OR: 2.53, 95% CI: 1.83 - 3.50), positive milking maneuver, (OR: 2.63, 95% CI: 1.78 - 3.91), positive subacromial impingement sign (OR: 1.92, 95% CI: 1.20 - 3.07), and positive posterior impingement sign (OR: 2.34, 95% CI: 1.67 - 3.28) compared to the subjects without symptomatic TOS. It is necessary to recognize that TOS is not a rare pathology in overhead-throwing athletes, especially baseball players, and that players with symptomatic TOS are at significantly higher risk of shoulder/elbow pain.