Learning Objective #1: understand the affect shoulder angle has on pelvic interface pressure while positioned laterally.

Learning Objective #2: understand that the shoulder angle positioned above 60 degrees with the pelvic tilt fixed at 30 degrees may increase the risk of skin damage.

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PURPOSE: The purpose of this study was to determine the degree of shoulder angle, which affects pelvic interface pressure in the lateral position. BACKGROUND: The 30 degree lateral tilt position is widely used to prevent pressure ulcers by reducing localized pressure over bony prominences. In this position, the shoulder angle is kept within a narrow angular range to decompress axillary vessels and nerves. However, various degrees of shoulder angle affecting pelvic interface pressure have not been fully evaluated. METHODS: Thirty-five healthy adults (BMI 21.44±2.80) participated in this study. For baseline measurement, they were in the supine position lying on a standard mattress with legs elevated by pillows. Using a XSENSOR™ body pressure mapping pad, the pelvic interface pressure was measured with the pelvic tilt fixed at 30 degrees and the degree of shoulder angle increased in 10 degree increments from 0 to 70 degrees. RESULTS: The supine position with 0 degree shoulder angle and a 30 degree pelvic tilt resulted in the lowest interface pressure. With the shoulder angle above 60 degrees, a significant difference of pelvic interface pressure was found (p < 0.05). However, there were no significant differences in pelvic interface pressure when measured with the shoulder angle at below 50 degrees. CONCLUSION: Keeping the shoulder angle within 0 to 50 degrees and the pelvic tilt fixed at 30 degrees may reduce pelvic interface pressure. Consequently, the positioning of patients will be determined based on individual needs or their physical conditions. Positioning the shoulder at an angle above 60 degrees may increase the risk of skin damage to the pelvic interface when the pelvic tilt is fixed at a 30 degree angle.