Lumbar spine and pelvis posterior posture assessments tend to examine the lower extremity for any changes in posture to determine the overall predisposing factors, aka issues which effect are kinetic chain.
The Lumbar Vertebrae are larger and heavier than vertebral bodies in other regions. The lumbar vertebral body is kidney shaped when viewed superiorly, so is wider from side to side than from front to back, and a little thicker in front than in back with a thin cortial shell which surrounds cancellous bone.
The posterior aspect of the vertebral body changes from slightly concave to slightly convex from L1 – L5 with an increasing diameter due to the increased load carried at each body. The main weight of the body is carried by the vertebral bodies and disks. The lamina, facets and spinous process are major parts of the posterior elements that help guide the movement of the vertebrae and protect the spinal cord.
Therapists/Physios tend to examine the lumbar spine in running shorts to aid in visual observation. If curvature is spotted, this may indicate a potential predisposing factor which could potentially lead to injury. These predisposing factors vary from; disc herniation, muscle spasm, scoliosis, muscle imbalance or lateral flexion due to the pelvis being raised on one side.
The pelvic region of the trunk includes the bony pelvis, the pelvic cavity (the space enclosed by the bony pelvis), the pelvic floor, below the pelvic cavity, and the perineum, below the pelvic floor. The pelvic skeleton is formed in the area of the back, by the sacrum and the coccyx and anteriorly and to the left and right sides, by a pair of hip bones.
The two hip bones connect the spine with the lower limbs. They are attached to the sacrum posteriorly, connected to each other anteriorly, and joined with the two femurs at the hip joints. The gap enclosed by the bony pelvis, called the pelvic cavity, is the section of the body underneath the abdomen and mainly consists of the reproductive organs (sex organs) and the rectum, while the pelvic floor at the base of the cavity assists in supporting the organs of the abdomen.
Therapists/Physios believe that postural imbalances can be addressed by adjusting the position of the pelvis, that whether the imbalance is in the upper or lower body. Therefore repositioning of the pelvis can aid in overcoming these imbalances.
Again, if the pelvis is slightly tilted, it indicates that the pelvis is laterally tilting upwards to the right and laterally tilted downwards to the left or right depending on which side is affected.
To compensate for a pelvis that is raised on either side, the affected individual may have increased lateral flexion of the lumbar spine which may correspond with the appearance of more or deeper skin creases on the affected side. This indicates that the quadratus lumborum muscle may be in a shortened position as well as the lumbar erector spinae muscles. If these muscles are affected, it could indicate further changes within the surrounding musculature; The hip joints aka, the Femoroacetabular could have reduced range of motion due to abductor and adductor shortening.
Posterior inferior iliac spine (PIIS)
another indicator that the alignment of the hips are two bony prominent landmarks known as the PIIS. The PIISs are located beneath the dimples some clients have in this region. A good indicator to determine if these prominent landmarks are out of alignment by using your thumbs and placing them on the dimples. If one thumb is higher than the other, it indicates a lateral tilt of the pelvis. Furthermore, the PIIS should be positioned in a horizontal plane at equal level.
This illustrates that any change in the posture from within the lumbar spine and pelvic can have many predisposing factors. Therefore, it is important to pay attention to your sport and occupation as these can have an effect on posture aswell.