No abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. There is a lack of numeric data for the mechanical characterization of spine muscles, especially in vivo data. The multifidus muscle is a major muscle for the stabilization of the spine and may be involved in the pathogenesis of chronic low back pain (LBP). Supersonic shear wave elastography (SWE) has not yet been used on back muscles. The purpose of this prospective study is to assess the feasibility of ultrasound SWE to measure the elastic modulus of lumbar multifidus muscle in a passive stretching posture and at rest with a repeatable and reproducible method.

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. CT-scans of 48 children, aged four months to 15 years. The geometry of the sternum was detailed 40 and nine parameters were used to describe the ribs and rib cages. A "costal index" was defined as 41 the ratio between cartilage length and whole rib length to evaluate the cartilage ratio for each rib 42 level. For all children, the costal index decreased from rib level one to three and increased from 43 level three to seven. For all levels, the cartilage accounted for 45 to 60% of the rib length, and was 44 longer for the first years of life. The mean costal index decreased by 21% for subjects over three 45 years old compared to those under three (p<10 -4 ). The volume of the sternebrae was found to be 46 highly age dependent. Such data could be useful to define the standard geometry of the paediatric 47 thorax and help to detect clinical abnormalities. 48