Global body compensations in ACL deficient knees.

ALERT: Ok, this is big.
It is a huge comment on what the brain and reflexive patterns impart on posture and gait when perceived functional instability is present.
This study aimed to investigate the gait modification strategies of trunk over right stance phase in patients with right anterior cruciate ligament deficiency.
* Here is what you need to ABSOLUTLY keep in mind when you read it. The 3D capture it telling you what they are DOING to strategize, not what is WRONG or what needs CORRECTING (our mantra it seems, sorry to keep beating this concept to death). This again hits home what I have been preaching for quite some time, that arm swing (and you can translate that to trunk movements, thorax, head posture, breathing etc) should not be coached or corrected unless you are absolutely sure there are clean symmetrical lower limb biomechanics (yes, you can easily and correctly argue that you can concurrently work on all parts). IF there is something going awry in a lower limb, compensations will occur above, they have to occur. So be absolutely sure you are not making therapeutic interventions above without making therapeutic corrections below. If you are working on a shoulder/upper quarter problem and are not looking for drivers in the lower limbs or in gait, well … . . good luck making lasting effects. Other than breathing, it can be argued well that gait locomotion is our 2nd most engaged motor pattern that we have driven to subconscious levels , and compensations are abound (but not without a cost), so we can dual++ task.
If you want to dive deeper into this, search our blog and look for my articles on Anti-phasic gait. This is essentially what this study was looking at, and confirming, that there is a distortion in the NORMAL opposite phase movements (anti-phasic) of the “shoulder girdle” and “pelvic girdle” when something goes wrong in a lower limb.
– Dr. Allen

Findings from Shi et al when there was a chronic right ACL deficiency:
-trunk rotation with right shoulder trailing over the right stance phase was lower in all five motion patterns
– trunk posterior lean was higher from descending stairs to walking when the knee sagittal plane moment ended
– trunk lateral flexion to the left was higher when ascending stairs at the start of right knee coronal plane moment when descending stairs at the maximal knee coronal plane moment and when descending stairs at the end of the knee coronal plane moment
– trunk rotation with right shoulder forward was higher at the minimal knee transverse plane moment and when the knee transverse plane moment ended
– during walking, trunk rotation with right shoulder trailing was lower at other knee moments during other walking patterns

http://www.ncbi.nlm.nih.gov/pubmed/27131179

Obesity and Base of Support

Recently we have been speaking and writing about “base of support” and how a narrow base of support will render a small comfort and control zone of balance in single leg tasking (walking, running, sports etc). We do not notice these things if we are standing on both feet or when walking or running per se, but all one needs to do is test a 30 second single leg stance to see how crappy one’s single limb base of support actually is. Most people will drift the pelvis laterally to get the single foot under the center of the body mass. This is a false support, it is a demonstration of weak support, unless you like to walk on a line/cross over gait. We should not have our knees rubbing together, scuffing our ankles or shoes together. If you do, you have a narrow base of support, have engrained a lazy style of locomotion, and you will wish and attempt to put the center of your body mass over the foot at all times. This is good if you are walking on ice, but that is about it. This is an epidemic, hence the prevalence of cross over gait out in the world. Increasing balance ability will help to increase base of support and hence help with reducing cross over gait (narrow step width gait and running) tendencies. Obesity seems to make this worse. Obesity in our world is wrecking our people, especially our kids.

“Alterations were detected in the intermittent postural control in obese children. According to the results obtained, active anticipatory control produces higher center of pressure displacement responses in obese children and the periods during which balance is maintained by passive control and reflex mechanisms are of shorter duration.”
“Differences in intermittent postural control between normal-weight and obese children ” Israel Villarrasa-Sapiña, Xavier García-Massó

http://www.gaitposture.com/article/S0966-6362(16)30091-1/abstract?platform=hootsuite