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  • Author: Timothy J. Walker x
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Timothy J. Walker, Jessica M. Tullar, Pamela M. Diamond, Harold W. Kohl III and Benjamin C. Amick III

Background: There is a need to understand physical activity types associated with health-related work limitations (also known as presenteeism). This study tests whether additive effects between physical activity types are associated with health-related work limitations among employees from a public university system. Methods: A cross-sectional study using health assessment data (n = 10,791) was used to examine aims. Analysis of covariance models tested differences in work limitations between physical activity groups based on combinations of stretching behavior, aerobic, and muscle-strengthening physical activities. Planned contrasts compared differences between selected groups. Results: There were significant group differences (P < .001) in reported work limitations after controlling for demographic, season, and health-related variables. Employees who reported participating in aerobic physical activity had significantly lower work limitation levels compared with inactive employees (P = .027). Employees who reported participating in both aerobic and muscle-strengthening physical activities had the lowest work limitation levels compared with all groups and significantly lower work limitation levels compared with employees who participated in aerobic physical activity only (P = .026). Conclusions: Results provide evidence of an additive effect where participating in a combination of aerobic and muscle-strengthening physical activities may be most beneficial when targeting health-related work limitations.

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Yumeng Li, Rumit S. Kakar, Marika A. Walker, Yang-Chieh Fu, Timothy S. Oswald, Cathleen N. Brown and Kathy J. Simpson

The purpose of the study was to determine if the intratrunk coordination of axial rotation exhibited by individuals with spinal fusion for adolescent idiopathic scoliosis (SF-AIS) during running varies from healthy individuals and how the coordination differs among adjacent trunk-segment pairs. Axial rotations of trunk segments (upper, middle, lower trunk) and pelvis were collected for 11 SF-AIS participants and 11 matched controls during running. Cross-correlation determined the phase lag between the adjacent segment motions. The coupling angle was generated using the vector coding method and classified into 1 of the 4 major, modified coordination patterns: in-phase, anti-phase, superior, and inferior phase. Two-way, mixed-model ANCOVA was employed to test phase lag, cross-correlation r, and time spent in each major coordination pattern. A significantly lower phase lag for SF-AIS was observed compared with controls. Qualitatively, there was a tendency that SF-AIS participants spent less time in anti-phase for middle-lower trunk and lower trunk-pelvis coordinations compared to controls. Phase lag and anti-phase time was significantly increased from cephalic to caudal segment pairs, regardless of group. In conclusion, SF-AIS participants and controls displayed similar patterns of intra-trunk coordination; however, the spinal fusion hindered decoupling of intra-trunk motions particularly between the lower trunk-pelvic motion.