Corrigendum to "Study protocol for the follow-up examination of the Nor-Hand study: A hospital-based observational cohort study exploring pain and biomarkers in people with hand osteoarthritis" [Osteoarthr. Cartil. Open 3 (2021) 100198].

[This corrects the article DOI: 10.1016/j.ocarto.2021.100198.].

Study protocol for the follow-up examination of the Nor-Hand study: A hospital-based observational cohort study exploring pain and biomarkers in people with hand osteoarthritis.

Objective: This study aims to increase the understanding of pain mechanisms in hand OA and explore potential risk factors for pain development or worsening in a biopsychosocial framework. Another important aim is to validate potential soluble and imaging OA biomarkers. Design: The follow-up examination of the Nor-Hand hospital-based observational cohort study started in October 2019 and was completed in May 2021. In total, 212 of the 300 participants with hand OA who were examined at baseline attended the follow-up study. The participants underwent clinical joint examinations, medical and functional assessments, quantitative sensory testing, fluorescence optical imaging, ultrasound of the hands, acromioclavicular joints, feet, knees and hips, conventional radiographs of the hands and feet and magnetic resonance imaging of the dominant hand. Blood and urine samples were collected, and all participants answered questions about demographic factors and OA-related questionnaires. Associations between disease variables and symptoms will be examined in cross-sectional and longitudinal analyses. Longitudinal analyses will be performed to assess the predictive value of baseline variables on hand OA outcomes. Conclusion: Current knowledge about predictors for disease progression in hand OA is limited, but with longitudinal data we will be able to explore the predictive value of baseline variables on hand OA outcomes, such as changes in patient-reported outcomes or changes in soluble and imaging biomarkers. This provides a unique opportunity to gain more knowledge about the natural disease course of hand OA.

Factors affecting running performance in 6-12-year-olds: The Health Oriented Pedagogical Project (HOPP).

AIMS: The purpose of this study was to examine factors affecting running performance in children. METHOD: A cross-sectional study exploring the relationships between height, weight, waist circumference, muscle mass, body fat percentage, relevant biomarkers, and the Andersen intermittent running test in 2272 children aged 6 to 12 years. Parental education level was used as a non-physiological explanatory variable. RESULTS: Mean values (SD) and percentiles are presented as reference values. Height (ß = 6.4, p < .0001), high values of haemoglobin (ß = 18, p = .013) and low percentage of body fat (ß = -7.5, p < .0001) showed an association with results from the running test. In addition, high parental education level showed a positive association with the running test. CONCLUSION: Boys display better running performance than girls at all age ages, except 7 years old, probably because of additional muscle mass and less fatty tissue. Height and increased level of haemoglobin positively affected running performance. Lower body fat percentage and high parental education level correlated with better running performance.