Clinical biomechanics
-
Clinical biomechanics · Mar 2013
Effects of cervical orthoses on neck biomechanical responses during transitioning from supine to upright.
Our objectives were to use a hybrid cadaveric/surrogate model to evaluate the effects of the cervicothoracic orthosis and collar on head and neck biomechanical responses during transitioning from supine to upright. ⋯ The simple maneuver of supine-to-upright transitioning, commonly performed clinically, produced complex neck loads and motions including head protrusion which caused cervical spine snaking. Neck motions consisted of extension at the upper cervical spine and flexion at the subaxial cervical spinal levels. Of the devices tested, the cervicothoracic orthosis, with anterior strut locked, provided the greatest cervical spine immobilization thereby reducing the risk of potential secondary neck injuries.
-
Clinical biomechanics · Mar 2013
Simulated transversus abdominis muscle force does not increase stiffness of the pubic symphysis and innominate bone: an in vitro study.
The transversus abdominis muscle is thought to exert a stiffening effect on the sacroiliac joints. However, it is unknown whether this muscle is capable of increasing pubic symphysis and innominate bone stiffness during load exerted on the pelvis. The objective of this study is to investigate whether in vitro simulated force of transversely oriented fibres of the transversus abdominis increases stiffness of the pubic symphysis and innominate bone. ⋯ Simulation of the force of a single muscle - transversus abdominis - does not increase stiffness of the pubic symphysis and innominate bone. The hypothesized stiffening influence of the transversus abdominis on the pelvic ring was not confirmed in vitro.
-
Clinical biomechanics · Mar 2013
Increasing posterior tibial slope does not raise anterior cruciate ligament strain but decreases tibial rotation ability.
It was investigated whether the strain of the anterior cruciate ligament and tibial kinematics are affected by increasing posterior tibial slope. ⋯ The hypothesis that increasing posterior tibial slope results in higher anterior cruciate ligament strain was not confirmed. However, knee kinematics were affected in terms of a reduced tibial rotation. From a biomechanical point of view the data do not support the efficacy of sagittal osteotomies as performed to stabilize anterior cruciate ligament deficient knees.
-
Clinical biomechanics · Feb 2013
A novel fixation system for sacroiliac dislocation fracture: internal fixation system design and biomechanics analysis.
Although there were many different types of fixation techniques for sacroiliac dislocation fracture, the treat remained challenging in posterior pelvic ring injury. The purpose of this study was to evaluate the biomechanical effects of a novel fixation system we designed. ⋯ The novel fixation system for unstable sacroiliac dislocation fractures produced sufficient stability in axial compression and axial rotation test in type C pelvic ring injuries. It may also offer a better solution for sacroiliac dislocation fractures.
-
Clinical biomechanics · Jan 2013
Bone properties by nanoindentation in mild and severe osteogenesis imperfecta.
Osteogenesis imperfecta is a heterogeneous genetic disorder characterized by bone fragility. Previous research suggests that impaired collagen network and abnormal mineralization affect bone tissue properties, however, little data is yet available to describe bone material properties in individuals with this disorder. Bone material properties have not been characterized in individuals with the most common form of osteogenesis imperfecta, type I. ⋯ The current study presents the first dataset describing bone material properties in individuals with the most common form of osteogenesis imperfecta, i.e., type I. Results indicate that intrinsic bone tissue properties are affected by phenotype. Knowledge of the material properties of bones in osteogenesis imperfecta will contribute to the ability to develop models to assist in predicting fracture risk.