Measurements of knee rotation-reliability of an external device in vivo

<p>Abstract</p> <p>Background</p> <p>Knee rotation plays an important part in knee kinematics during weight-bearing activities. An external device for measuring knee rotation (the Rottometer) has previously been evaluated for validity by simultaneous measurements of skeletal movements with Roentgen Stereometric Analysis (RSA). The aim of this study was to investigate the reliability of the device.</p> <p>Method</p> <p>The within-day and test-retest reliability as well as intertester reliability of the device in vivo was calculated. Torques of 3, 6 and 9 Nm and the examiner's apprehension of end-feel were used at 90°, 60° and 30° of knee flexion. Intraclass Correlation Coefficient _2,1(ICC _2,1), 95% confidence interval (CI) of ICC and 95% CI between test trials and examiners were used as statistical tests.</p> <p>Result</p> <p>ICC_2,1ranged from 0.50 to 0.94 at all three flexion angles at 6 and 9 Nm as well as end-feel, and from 0.22 to 0.75 at 3 Nm applied torque.</p> <p>Conclusion</p> <p>The Rottometer was a reliable measurement instrument concerning knee rotation at the three different flexion angles (90°, 60° and 30°) with 6 and 9 Nm applied torques as well as the examiner's apprehension of end-feel. Three Nm was not a reliable torque. The most reliable measurements were made at 9 Nm applied torque.</p

Residential Selection across the Life Course : Adolescent Contextual and Individual Determinants of Neighborhood Disadvantage in Mid-Adulthood.

BACKGROUND: Numerous cross-sectional studies have examined neighborhood effects on health. Residential selection in adulthood has been stressed as an important cause of selection bias but has received little empirical attention, particularly its determinants from the earlier life course. The present study aims to examine whether neighborhood, family, school, health behaviors and health in adolescence are related to socioeconomic disadvantage of one's neighborhood of residence in adulthood. METHODS: Based on the prospective Northern Swedish Cohort (analytical N = 971, 90.6% retention rate), information was collected at age 16 years concerning family circumstances, school adjustment, health behaviors and mental and physical health. Neighborhood register data was linked to the cohort and used to operationalize aggregated measures of neighborhood disadvantage (ND) at age 16 and 42. Data was analyzed with linear mixed models, with ND in adulthood regressed on adolescent predictors and neighborhood of residence in adolescence as the level-2 unit. RESULTS: Neighborhood disadvantage in adulthood was clustered by neighborhood of residence in adolescence (ICC = 8.6%). The clustering was completely explained by ND in adolescence. Of the adolescent predictors, ND (b = .14 (95% credible interval = .07-.22)), final school marks (b = -.18 (-.26--.10)), socioeconomic disadvantage (b = .07 (.01-.14)), and, with borderline significance, school peer problems (b = .07 (-.00-.13)), were independently related to adulthood ND in the final adjusted model. In sex-stratified analyses, the most important predictors were school marks (b = -.21 (-.32--.09)) in women, and neighborhood of residence (ICC = 15.5%) and ND (b = .20 (.09-.31)) in men. CONCLUSIONS: These findings show that factors from adolescence - which also may impact on adult health - could influence the neighborhood context in which one will live in adulthood. This indicates that residential selection bias in neighborhood effects on health research may have its sources in early life