ABSTRACT
OBJECTIVES: To test the hypotheses that (1) wearing a flexible wrist splint while taking an object from a box increases known postural risk factors for shoulder disorders and (2) that the height of the front of the box modulates the effect on shoulder kinematics of wearing a wrist splint. DESIGN: A controlled laboratory experiment with 2 factors (splint wearing, box height). SETTING: Human performance laboratory. PARTICIPANTS: Ten consecutive healthy volunteers (5 men, 5 women; age range, 19-32 y). INTERVENTIONS: Experimental manipulation of wrist immobilization and box height. MAIN OUTCOME MEASURES: Humeral plane of elevation, humeral elevation, and humeral axial rotation. RESULTS: Wearing a wrist splint increased the maximum humeral elevation angle (P<.001), and the height of the barrier also increased the maximum humeral elevation angle (P<.001). The average difference in maximum humeral elevation between the splint and the no splint conditions was 6.8 degrees . CONCLUSIONS: Wearing a wrist splint while performing a job that requires removing objects from a box can increase risk factors for shoulder disorders. Workplace analysis should be performed to avoid secondary injuries before a patient wearing a wrist splint returns to work.
