No abstract

Background Shoulder impingement syndrome (SIS) is the most common form of shoulder pain and a persistent musculoskeletal problem. Conservative and invasive treatments, aimed at the shoulder joint, have had limited success. Research suggests shoulder function is related to thoracic posture, but it is unknown whether thoracic posture is associated with SIS. Objective The objective of this study was to investigate whether there is a relationship between SIS and thoracic posture. Design This was a case control study. Methods Thoracic posture of 39 participants with SIS and 39 age-, gender-, and dominant arm-matched controls was measured using the modified Cobb angle from a standing lateral radiograph. Thoracic range of motion (ROM) was also measured using an inclinometer. Between-group differences were compared using t tests. The relationship between thoracic posture and thoracic ROM was determined with linear regression. Results Twenty women and 19 men with SIS (mean age = 57.1 years, SD = 11.1) and 39 age-matched, gender-matched, and dominant arm-matched controls (mean age = 55.7years, SD = 10.6) participated. Individuals with SIS had greater thoracic kyphosis (mean difference = 6.2o, 95% CI 2.0–10.4) and less active thoracic extension (7.8o, 95% CI = 2.2–13.4). Greater thoracic kyphosis was associated with less extension ROM (ie, more flexion when attempting full extension: β = 0.71, 95% CI = 0.45–0.97). Limitations These cross-sectional data can only demonstrate association and not causation. Both radiographic measurements and inclinometer measurements were not blinded. Conclusion Individuals with SIS had a greater thoracic kyphosis and less extension ROM than age- and gender-matched healthy controls. These results suggest that clinicians could consider addressing the thoracic spine in patients with SIS.

Silicon-Carbide (SiC) device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon (Si) counterpart, SiC offers a greater possibility for high powered switching applications in extreme environment. In particular, SiC Metal-Oxide-Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing SiC power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.

No abstract

The gravity-dependent (analogue) inclinometer produces angles that are comparable to the modified Cobb angle obtained from radiographs, establishing its criterion validity as a safe clinical tool for measuring thoracic kyphosis.