Summary We compared the relationship between sedentary activity (SA) and physical activity (PA) with bone mineral density (BMD) and body fat percentage in the United States and found a negative association between SA and BMD and a positive association with body fat percentage. a positive association between PA and BMD and a negative association with body fat percentage. Introduction SA and PA are associated with changes in skeletal parameters and body fat percentage, and we aimed to investigate and compare the relationship between SA, PA and bone mineral density (BMD) and body fat percentage in men and women. Methods We assessed the relationship between SA, PA and BMD and body fat percentage in 9249 Americans aged 20-80 years (mean age 38.26 ± 11.39 years) from NHANES 2011-2018.BMD and body fat percentage were measured by dual-energy X-ray bone densitometry (DXA). We used multiple linear regression models to examine the relationships between SA, PA and total BMD and total body fat percentage, adjusted for a large number of confounding factors. Results After adjusting for race/ethnicity, age, alcohol and smoking behavior, body mass index (BMI), total protein, blood calcium, blood uric acid, cholesterol, blood phosphorus, and blood urea nitrogen, SA was negatively associated with total BMD (β =-0.002 95% CI: -0. 003-0.001, P < 0.001) and SA was positively associated with total lipid percentage (β =0.149 95% CI: 0.111-0.186, P < 0.001). There was a positive correlation between multiple PAs and BMD and a negative correlation between multiple PAs and percent body fat. Conclusions Our results show that physical activity is a key component of maintaining bone health in both men and women and is strongly associated with lower body fat percentages. Sedentary activity has deleterious effects on skeletal homeostasis and is strongly associated with increased body fat percentage. Healthcare policymakers should advise people to be less sedentary and more physically active in the prevention of osteoporosis and obesity.

We compared the relationship between sedentary activity (SA) and physical activity (PA) with bone mineral density (BMD) and body fat percentage in the United States and found a negative association between SA and BMD and a positive association with body fat percentage. A positive association between PA and BMD and a negative association with body fat percentage. SA and PA are associated with changes in skeletal parameters and body fat percentage, and we aimed to investigate and compare the relationship between SA, PA and bone mineral density (BMD) and body fat percentage in men and women. We assessed the relationship between SA, PA and BMD and body fat percentage in 9787 Americans aged 20–59 years (mean age 38.28 ± 11.39 years) from NHANES 2011–2018. BMD and body fat percentage were measured by dual-energy X-ray bone densitometry (DXA). We used multiple linear regression models to examine the relationships between SA, PA and lumbar spine BMD and total body fat percentage, adjusted for a large number of confounding factors. After adjusting for race/ethnicity, age, alcohol and smoking behavior, body mass index (BMI), total protein, blood calcium, blood uric acid, cholesterol, blood phosphorus, vitamin D, and blood urea nitrogen, SA was negatively associated with lumbar spine BMD (β = − 0.0011 95% CI − 0.0020 to − 0.0002, P = 0.022), and SA was positively associated with total fat percentage (β = PA was positively associated with lumbar BMD (β = 0.0046 95% CI 0.0010 to 0.0082, P = 0.012) and there was a negative association between PA and body fat percentage (β = − 1.177 95% CI − 1.326 to –1.027, P < 0.001). Our results show that physical activity is a key component of maintaining bone health in both men and women and is strongly associated with lower body fat percentages. Sedentary activity is negatively correlated with bone density and is strongly associated with an increase in body fat percentage. Healthcare policy makers should consider reducing sedentary activity and increasing physical activity when preventing osteoporosis and obesity.

To determine the pattern of intra-articular calcaneal fractures (ICFs) by a three-dimensional (3D) mapping and determine whether there were consistent fracture patterns and comminution zones. In this study, 67 patients with ICFS by CT scan were included. The calcaneal fractures fragments in CT were multiplanar reconstructed and virtual reduced. 3D heat mapping was subsequently created by graphically superimposing all fracture lines onto a standard calcaneal template. The cohort included 26 (38.8%) left calcaneal fractures, 27 (40.30%) right calcaneal fractures, and 14 (20.9%) cases with bilateral fractures. Comminuted fractures accounted for 92.5%. Sagittal 3D mapping shows that the fracture line is mainly concentrated at the critical angle of Gissane and extending rear to the posterior of the tuberosity of the lateral wall and the anterior of the medial process of the calcaneus tuberosity but with more significant variation in the medial wall. The average angle of fracture lines concerning the long calcaneal axis (LCA) was 29.1° and 19.2° in the lateral and medial walls. Axial 3D mapping shows that fracture lines were primarily concentrated in the anterior area to the posterior joint facet and extending along the rear joint facet and calcaneus sulcus to the posteriorly of the tuberosity. The mean angle of fracture lines concerning the LAC was 11° in the axial wall. Our data provided elucidated that ICFs have consistent characteristic fracture patterns and comminution zones. This study provides visual guidelines for understanding fracture morphology, which may assist with fracture classification, preoperative planning, development of fixation concepts.

Background: To determine the pattern of intra-articular calcaneal fractures (ICFs) by a three-dimensional (3D) mapping and determine whether there were consistent fracture patterns and comminution zones. Methods: Sixty-seven patients with ICFS by CT scan were included. The calcaneal fractures fragments in CT were multiplanar reconstructed and virtual reduced. 3D heat mapping was subsequently created by graphically superimposing all fracture lines onto a standard calcaneal template.Results: The cohort included 26 (38.8%) left calcaneal fractures, 27 (40.30%) right calcaneal fractures, and 14 (20.9%) cases with bilateral fractures. Comminuted fractures accounted for 92.5%. Sagittal 3D mapping shows that the fracture line is mainly concentrated at the critical angle of Gissane and extending rear to the posterior of the tuberosity of the lateral wall and the anterior of the medial process of the calcaneus tuberosity but with more significant variation in the medial wall. The average angle of fracture lines concerning the long calcaneal axis (LCA) was 29.1°and 19.2° in the lateral and medial walls. Axial 3D mapping shows that fracture lines were primarily concentrated in the anterior area to the posterior joint facet and extending along the rear joint facet and calcaneus sulcus to the posteriorly of the tuberosity. The mean angle of fracture lines concerning the LAC was 11° in the axial wall. Conclusion: The data provided elucidated that ICFs have consistent characteristic fracture patterns and comminution zones. This study provides visual guidelines for understanding fracture morphology, which may assist with fracture classification, preoperative planning, development of fixation concepts.