Transverse flexion

In a first approach to the study of beam bending, it is convenient to make some hypotheses (1). The first of these hypotheses is that the sections that are flat before flexion remain flat after flexion. For slender beams—that is, for beams whose transverse dimensions are small in comparison with their length—this hypothesis is substantially correct. In this case, the shear effects in the cross sections are relatively negUgible. It will be further assumed that the inertial forces arising from the rotation of each element around its center of mass can be ignored. This is, in fact, the second hypothesis. 

The analysis of the balance of forces on the lateral surface of the beam carried out on the basis of the preliminary hypothesis indicates that the only nonzero component of the stress tensor is simple extension. In fact, some parts of the transverse section are under tension, and others are under compression, and the two effects combined produce the flexion. According to Figure 17.1, the component jxx of the strain is given by... 

A new example of deformation of a rod, in which small strains are compatible with large displacements of parts of the rod, is torsion (1, p. 59). In a rod under torsion whose axis is kept straight, without flexion or bulge, each transverse section rotates relative to those located close to it. Consequently, if the rod is long, two sufficiently distant sections can rotate through a large angle relatively to each other. 

Lateral flexion of the torso Rotation of the torso Transverse torsion of the torso Pressure intensity of the belt on the collarbone Muscular stress intensity of the neck X... 

V shows the transverse ligament. The 2.4-mm guide wire for the AM tunnel should be inserted just posterior to the transverse ligament at 90° knee flexion. The AM tunnel position must not be too anterior to the ACL tibial attachment. It is important to maintain 90° knee flexion to avoid misplacement caused by changing the position of the transverse ligament... 

Psoas This muscle is attached to the vertebral body at a point opposite the center of rotation of the vertebra, so it is attached to the base of the pedicle and the anterior surface of the transverse process. It is inserted at the lesser trochanter of the femur and alters lordosis of the lumbar spine. Hip flexion contractures permit shortening of the psoas, which increases lordosis. Further contracture of the muscle has a tendency to pull the mid-lumbar spine forward and inferiorly. 

Children can also sustain a transverse fracture through the mid-portion of the patella or a stellate pattern fracture. These can occur from falls with the knee in flexion or severe contraction of the quadriceps tendon. These are best seen on the lateral projection. Transverse stress fractures occur due to abnormal quadriceps pull on osteopenic bones in children with cerebral palsy. 

For example, on palpation, the transverse process of the fourth thoracic vertebra is more prominent posteriorly on the right. Is it part of a somatic dysfunction complex involving three planes and six motions on a helical axis The vertebra is placed into a position of flexion. The right transverse process becomes more prominent posteriorly. It is assumed that this has happened because there is a barrier preserrt to the motion of flexion, and the vertebra is resporrding according to the rale of the effect of resistance on linear motion. That is, on meeting this flexion barrier, the vertebra turns away from and arotmd it in the direction of allowable freedom of motion, or right rotation. 

The occipitoatlantal articulation consists of the superior articular facets of the atlas and the two occipital condyles. The superior facets of the atlas face backward, upward, and medially, and are concave in both anteroposterior and transverse diameters. The surfaces of the occipital condyles match the facets of the atlas, and the joint is best thought of as a sphere (the occiput) gliding on the articular surfaces of the atlas (Fig. 24-1). The freely movable occiput is limited by its muscular and ligamentous attachments, which make flexion-extension the primary motion, producing a smaii-amplitude nodding of the head. Flexion of the occiput on the atlas is accompanied by a posterior translatory slide of the occiput extension is accompanied by an anterior translatory slide. 

The atlantoaxial articulation is specially adapted for (nearly) pure rotation. In addition to the inferior articular facets of the atlas and the superior articular facets of the axis, movement other than rotation is limited by the anteriorly located odontoid process (dens) of the axis. The odontoid process is held close to the anterior arch of the atlas by the transverse ligament of the atlas, which allows only a slight amount of flexion of the atlas on the axis. 

Rotoscoliosis testing evaluates the rotational position of the vertebrae with respect to the position of the transverse processes. This position is evaluated with the spine in neutral position, in flexion, and in extension. 

Roll the thumbs superiorly and press down on the superior aspect of the transverse processes, thus placing the vertebrae into flexion (Fig. 36-8). 

Transverse process of T8 is posterior on the right and most prominent in flexion. Diagnosis T8 E SRRR-... 

The physician side-bends and rotates the patient down to and toward the posterior transverse process. The physician can further exaggerate this if necessary until softening of the underlying tissue is noted. Slight flexion or extension is added, depending on the diagnosis of the dysfunction, finishing the position into the relative freedoms of the somatic dysfunction (Fig. 41-3). 

L Patient position Side-tying on the table. The posteriorly rotated transverse process to be treated is downward, toward the table. The patient will be placed into a lateral recumbent position (the rrmemonic "FDR" may be used to indicate Flexion, posterior facets Down ward, and Recrrmbent position). 

Sacral flexion and extension are caused ly-respiratory motion and occur on a superior transverse axis, also known as the respiratory axis, that is located at the level of the articular processes of the second sacral segment... 

If the posterior transverse process becomes more so (increase in asymmetry), then flexion is the barrier. If the transverse processes become more symmetrical, then flexion is the freedom. The side-bending and rotation of the diagnosis is to the side of the posterior transverse process. 

Flexion of the sphenobasilar junction results in a slight relative elevation of that articulation. The midline bones all rotate about a transverse axis into flexion (Fig. 104-1). Paired lateral bones move into external rotation. During extension, opposite motions occur (Fig. 104-2). All motions are subtle and may be sensed by hand contact. This motion is not generally perceptible by visual examination. 

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