The lumbar spine has an intrinsic shape specific to each individual that remains a characteristic throughout flexion and extension

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Variation in lifting kinematics related to individual intrinsic lumbar curvature:An investigation in healthy adults

Objective Lifting postures are frequently implicated in back pain. We previously related responses to a static load with intrinsic spine shape, and here we investigate the role of lumbar spine shape in lifting kinematics. Methods Thirty healthy adults (18-65 years) performed freestyle, stoop and squat lifts with a weighted box (6-15 kg, self-selected) while being recorded by Vicon motion capture. Internal spine shape was characterised using statistical shape modelling (SSM) from standing mid-sagittal MRIs. Associations were investigated between spine shapes quantified by SSM and peak flexion angles. Results Two SSM modes described variations in overall lumbar curvature (mode 1 (M1), 55% variance) and the evenness of curvature distribution (mode 2 (M2), 12% variance). M1 was associated with greater peak pelvis (r=0.38, p=0.04) and smaller knee flexion (r=-0.40, p=0.03) angles; individuals with greater curviness preferred to lift with a stooped lifting posture. This was confirmed by analysis of those individuals with very curvy or very straight spines (|M1|&gt;1 SD). There were no associations between peak flexion angles and mode scores in stoop or squat trials (p&gt;0.05). Peak flexion angles were positively correlated between freestyle and squat trials but not between freestyle and stoop or squat and stoop, indicating that individuals adjusted knee flexion while maintaining their preferred range of lumbar flexion and that 'squatters' adapted better to different techniques than 'stoopers'. Conclusion Spinal curvature affects preferred lifting styles, and individuals with curvier spines adapt more easily to different lifting techniques. Lifting tasks may need to be tailored to an individual's lumbar spine shape.</p

Significant morphological change in osteoarthritic hips identified over 6-12 months using Statistical Shape Modelling

Acknowledgements We are grateful to all the study participants. We thank Lana Gibson and Jennifer Scott for their expertise with the iDXA scanner as well as iDXA precision data. Funding source This study was supported by an award (Ref: WHMSB_AU068/071) from the Translational Medicine Research Collaboration – a consortium made up of the Universities of Aberdeen, Dundee, Edinburgh and Glasgow, the four associated NHS Health Boards (Grampian, Tayside, Lothian and Greater Glasgow & Clyde), Scottish Enterprise and initially Wyeth, now Pfizer. The funder had no involvement in the collection, analysis and interpretation of data; in the writing of the manuscript; or in the decision to submit the manuscript for publication. Dr J.S. Gregory was the holder of an MRC New Investigator award (Ref: G0901242).Peer reviewedPostprin

Reproducibility and Diagnostic Accuracy of Kellgren-Lawrence Grading for Osteoarthritis Using Radiographs and Dual-Energy X-ray Absorptiometry Images

Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved. The authors would like to thank all the study volunteers, radiographers Lana Gibson and Jennifer Scott as well as Carol McKerron for administrative support. The acquisition of scans was supported in part by an award (Ref: WHMSB_AU_068_071) from the Translational Medicine Research Initiative - a consortium made up of the Universities of Aberdeen, Dundee, Edinburgh and Glasgow, the four associated NHS Health Boards (Grampian, Tayside, Lothian and Greater Glasgow & Clyde), Scottish Enterprise and Pfizer. Kanako Yoshida is funded by the Grampian Osteoporosis Trust (GOT). Jennifer Gregory is supported by the Medical Research Council [G0901242].Peer reviewedPostprin

Motor development in infancy and spine shape in early old age: findings from a British birth cohort study

Spine shape changes dramatically in early life, influenced by attainment of developmental milestones such as independent walking. Whether these associations persist across life is unknown. Therefore, we investigated associations between developmental milestones and spine shape, as determined using statistical shape models (SSMs) of lumbar spine from DXA scans in 1327 individuals (688 female) at 60‐64y in the MRC National Survey of Health and Development. Lumbar lordosis angle (L4 inferior endplate to T12 superior endplate) was measured using the two‐line Cobb method. In analyses adjusted for sex, height, lean and fat mass, socioeconomic position and birthweight, later walking age was associated with greater lordosis described by SSM1 (regression coefficient 0.023, 95%CI 0.000‐0.047, p=0.05) and direct angle measurement. Modest associations between walking age and less variation in anterior‐posterior vertebral size caudally (SSM6) were also observed (0.021, 95%CI ‐0.002‐0.044, p=0.07). Sex interactions showed that later walking was associated with larger relative vertebral anterior‐posterior dimensions in men (SSM3; ‐0.043, 95%CI ‐0.075‐0.01, p=0.01) but not women (0.018, 95%CI ‐0.0007‐0.043, p=0.17). Similar associations were observed between age at independent standing and SSMs but there was little evidence of association between sitting age and spine shape. Unadjusted associations between walking age and SSMs 1 and 6 remained similar after adjustment for potential confounders and mediators. This suggests that these associations may be explained by altered mechanical loading of the spine during childhood growth, although other factors could contribute. Early life motor development, particularly walking, may have a lasting effect on features of spine morphology with clinical significance

Age at onset of walking in infancy is associated with hip shape in early old age

Bones' shapes and structures adapt to the muscle and reaction forces they experience during everyday movements. Onset of independent walking, at approximately 12 months, represents the first postnatal exposure of the lower limbs to the large forces associated with bipedal movements, and, accordingly, earlier walking is associated with greater bone strength. However, associations between early life loading and joint shape have not been explored. We therefore examined associations between walking age and hip shape at age 60-64y in 1423 individuals (740 women) from the MRC National Survey of Health and Development, a nationally-representative British birth cohort. Walking age in months was obtained from maternal interview at age 2y. Ten modes of variation in hip shape (HM1-HM10), described by statistical shape models, were ascertained from dual-energy X-ray absorptiometry (DXA) images. In sex-adjusted analyses, earlier walking age was associated with higher HM1 and HM7 scores; these associations were maintained after further adjustment for height, body composition and socioeconomic position. Earlier walking was also associated with lower HM2 scores in women only, and lower HM4 scores in men only. Taken together, this suggests that earlier walkers have proportionately larger (HM4) and flatter (HM1,4) femoral heads, wider (HM1,4,7) and flatter (HM1, 7) femoral necks, smaller neck-shaft angle (HM1,4), anteversion (HM2,7) and development of osteophytes (HM1). These results suggest that age at onset of walking in infancy is associated with variations in hip shape in older age. Early walkers have a larger femoral head and neck and smaller neck-shaft angle; these features are associated with reduced hip fracture risk, but also represent an osteoarthritic-like phenotype. Unlike results of previous studies of walking age and bone mass, associations in this study were not affected by adjustment for lean mass suggesting that associations may relate directly to skeletal loading in early life when joint shape changes rapidly. This article is protected by copyright. All rights reserved.</p

Investigation of the Relationship Between Susceptibility Loci for Hip Osteoarthritis and Dual X-Ray Absorptiometry–Derived Hip Shape in a Population-Based Cohort of Perimenopausal Women

This publication is the work of the authors and does not necessarily reflect the views of any funders. Supported by the UK Medical Research Council (grant G1001357 for collection of hip shape), and the Wellcome Trust (grants WT092830M for collection of hip shape and WT088806 for genotyping). Core support for the Avon Longitudinal Study of Parents and Children is provided by the UK Medical Research Council, the Wellcome Trust (102215/2/13/2), and the University of Bristol. Dr. Baird's work was supported by Arthritis Research UK (grant 20244). Mr. Faber's work was supported by an Elizabeth Blackwell Institute Clinical Research Primer Scheme.Peer reviewedPostprin

Associations between life course longitudinal growth and hip shapes at ages 60-64 years: evidence from the MRC National Survey of Health and Development

Objective We sought to examine associations between height gain across childhood and adolescence with hip shape in individuals aged 60-64 years from the Medical Research Council National Survey of Health and Development, a nationally representative British birth cohort. Methods Height was measured at ages 2, 4, 6, 7, 11 and 15 years, and self-reported at age 20 years. 10 modes of variation in hip shape (HM1-10), described by statistical shape models, were previously ascertained from DXA images taken at ages 60-64 years. Associations between (1) height at each age; (2) Super-Imposition by Translation And Rotation (SITAR) growth curve variables of height size, tempo and velocity; and (3) height gain during specific periods of childhood and adolescence, and HM1-10 were tested. Results Faster growth velocity was associated with a wider, flatter femoral head and neck, as described by positive scores for HM6 (regression coefficient 0.014; 95% CI 0.08 to 0.019; p<0.001) and HM7 (regression coefficient 0.07; 95% CI 0.002 to 0.013; p=0.009), and negative scores for HM10 (regression coefficient -0.006; 95% CI -0.011 to 0.00, p=0.04) and HM2 (males only, regression coefficient -0.017; 95% CI -0.026 to -0.09; p<0.001). Similar associations were observed with greater height size and later height tempo. Examination of height gains during specific periods of childhood and adolescence identified those during the adolescence period as being most consistently associated. Conclusion Our analyses suggest that individual growth patterns, particularly in the adolescent period, are associated with modest variations in hip shape at 60-64 years, which are consistent with features seen in osteoarthritis

The role of biophysical cohesion on subaqueous bed form size

Biologically active, fine-grained sediment forms abundant sedimentary deposits on Earth's surface, and mixed mud-sand dominates many coasts, deltas, and estuaries. Our predictions of sediment transport and bed roughness in these environments presently rely on empirically based bed form predictors that are based exclusively on biologically inactive cohesionless silt, sand, and gravel. This approach underpins many paleoenvironmental reconstructions of sedimentary successions, which rely on analysis of cross-stratification and bounding surfaces produced by migrating bed forms. Here we present controlled laboratory experiments that identify and quantify the influence of physical and biological cohesion on equilibrium bed form morphology. The results show the profound influence of biological cohesion on bed form size and identify how cohesive bonding mechanisms in different sediment mixtures govern the relationships. The findings highlight that existing bed form predictors require reformulation for combined biophysical cohesive effects in order to improve morphodynamic model predictions and to enhance the interpretations of these environments in the geological record

Associations between body mass index across adult life and hip shapes at age 60 to 64:Evidence from the 1946 British birth cohort

Funding: The NSHD is funded by the UK Medical Research Council. SGM, RC, RJH and DK are supported by the UK Medical Research Council (Programme codes: MC_UU_12019/1, MC_UU_12019/2 and MC_UU_12019/4). This project was funded by the UK Medical Research Council (Grant MR/L010399/1) which supported SGM, AVP and FRS. The funders of the study had no role in study design, data collection, data analysis, data interpretation or writing of this manuscript. Acknowledgements: We thank Dr. Michael Machin for his valuable assistance obtaining the images and the University of Aberdeen Data Management Team for programming support for ‘Shape’. The authors are grateful to NSHD study members who took part in the clinic data collection for their continuing support. We thank members of the NSHD scientific and data collection teams at the following centres: MRC Unit for Lifelong Health and Ageing; Wellcome Trust (WT) Clinical Research Facility (CRF) Manchester; WTCRF and Medical Physics at the Western General Hospital in Edinburgh; WTCRF and Department of Nuclear Medicine at University Hospital Birmingham; WTCRF and the Department of Nuclear Medicine at University College London Hospital; CRF and the Department of Medical Physics at the University Hospital of Wales; CRF and Twin Research Unit at St Thomas' Hospital London. Data used in this publication are available to bona fide researchers upon request to the NSHD Data Sharing Committee via a standard application procedure. Further details can be found at: http://www.nshd.mrc.ac.uk/data; doi: http://dx.doi.org/10.5522/NSHD/Q102; doi: http://dx.doi.org/10.5522/NSHD/Q102A.Peer reviewedPublisher PD