The post from 2012 essentially detailed some of the fundamental criteria for efficiently (and accurately) putting the issue of hip subluxation into perspective. To be specific, the fundamental failure to implement a more comprehenisve assessment of the hip before making any decisions on intervention that are more invasive than what is actually required.
In continuing this narrative, beyond providing some insight into accurate analysis and assessment, it is equally important to provide some clarity as to "why" the issue of hip subluxation / dysplasia / dislocation is so pervasive in Cerebral Palsy (CP) and other disorders of movement and posture. To be clear, every child is unique and every person manifests unique challenges and symptoms...however, there are some developmental links that can be traced back to fundamental "roots" of these challenges. Although understanding does not provide a formal "solution" to these challenges, understanding WHY they develop is fundamental to providing parents and family with some sense of clarity, direction, and understanding. These are all elements that sometimes get lost in the search for the best solution.
In a post from December of last year called Respiration and Neurodevelopmental Disorders: Part 2, I outlined the fundamental (and critical) link between respiration and the development / growth of the pelvis. In brief, the immediate engagement of the respiratory mechanism (immediately after birth) is the most important catalyst for the continuing development of the shoulder girdle and pelvic girdle. In other words, if this mechanism is altered or deficient (which it is in the case of CP, pre-mature births, and other developmental disorders) they cascade effect is that the HEALTHY development of the pelvis is altered as well. Why is this relevant? We should all understand (and integrate) the reality that the legs (and their performance and function) are completely dependant on a well-developed and fully developed pelvis. Therefore, ANY deficit in the pelvis (volume, integrity, etc...) will reflect in the legs.
So...what is happening in the pelvis (specifically) that has this effect of creating consistent environments that allow for subluxation?
To be precise, the respiratory dysfunction essentially triggers a delay in the volumetric development of the thorax (chest) and pelvis...in other words, developmental growth is much slower than chronological growth (age). Additionally, while volumetric development is significantly delayed, longitudinal growth tends to remain in place. To put it more specifically, the legs grow in length at a rate that is more proportional to the childs age. The result:
As the child gets older, the pelvis remains relatively small while the legs continue to grow and develop (in density and muscular mass) at a rate that is more aligned with chronoligical age...which formally gets characterized by an attempt to "fit legs into a pelvis that is architecturally too small to accomodate them."
If you examine any x-ray of a child with CP (or even a simple photo, for that matter), you will notice that the pelvis and upper thorax almost always appear much smaller in proportion to the rest of the body. In addition, they will appear significantly smaller when compared to a healthy child of the same age. Therefore if you were take a child of 4 years old, the "developmental age" of their pelvis would be more approximate of a child of 2 years old...this architectural "mismatch" essentially results in the body trying to insert 4 year old legs into a 2 year old pelvis.
From a biomechanical perspective, this is just not possible. The result is profound joint instability, severe muscular imbalances (weakness, tightness), mechanical stresses on the ligaments and tendons, and...possibly / eventually...situations of hip pathology (subluxation / dysplasia / dislocation).
The next set of practical questions a parent or professional may have would likely be derived from "where does all of this information take us....what can we do about it?" Of course, there are a number of interventions that are generally intuitive and show some definite benefit...but in the realization that respiration plays a fundamental role in the health and development of the pelvis, it makes strategic sense to include / integrate any and all strategies that address an improvement in respiratory mechanics. This is precisely why the most fundamental element of the Fascia Therapy concept is the Respiratory Protocol. By efficiently addressing respiratory mechanics and "redistributing" the healthy hydraulic stimulus of respiration, we are essentially "restarting" and re-initiating the proper respiratory stimulus that was missing from the beginning. When combined with additional carefully selected interventions, the challenges of hip subluxation can more often than not be reduced and, in some cases, reversed. This is a strategy that can help to avoid those options that are significantly more invasive and generally painful.
In summary, the issue of hip subluxation remains one of the most prevalent concerns and preoccupations in most families. Although it is sometimes the subject of "hot debate", this debate is almost exclusively rooted in how to "fix" it. This is (of course) intuitive and important...however, in order to ensure that the chosen method of "fixing" is, in fact, the best one for your child, you should (at the very least) have a solid grasp on what is going on from a developmental / architectural standpoint as well as an understanding as to why these issues "pop up" in almost all cases and almost always within a specific age range.
Hopefully this provides some insight into understanding some of the "why's".