Functional Hallux Limitus, my project so far...

Kevin,

The problem here is that there is no specific mechanical phenomenon. Each individual demonstates a unique compensatory response to what we believe to be an interferance in the sagittal progression. I doubt if this would lend it self to quantifiable math.

Graham

 

I believe many "authorities" previously believed that also about the orbit of the planets....then along came Sir Isaac Newton and his calculus....and the rest is history.

http://zebu.uoregon.edu/~soper/Orbits/newtonplanets.html

 

Kevin,

Quantum mechanics and the laws of physics explain nicely the predictable motion of the planets. I think that when dealing with biologically variable structures and unpredictable compensations and symptoms you would need to consider chaos theory perhaps.

Regards

 

Lets play spot the difference. Graham, the self-proclaimed "sagittal plane facilitator" thinks each compensatory pattern is unique; while Howard, the guy that developed sagittal plane facilitation theory states that the compensation is quite predictable. These views appear somewhat dichotomous.

Who's your money on? :boxing:

 

Lyapunov exponent for sagittal plane perturbation = ?

 

Simon,

The pattern of gait "disturbances" is reasonably predictable. The extent to which each individual distubance is observed will vary. The application/prescription of the orthoses is reasonably predictable as is the outcome expected.

The main variation is in the symptoms presented by individuals who demonstrate very similar gait patters.

 

Hi Graham,

As much as I enjoy your posts and agree with your overall philosophy, I think there are very specific mechanical phenomena which occur; they are classifiable, and with the right mathematics, quite predictable. Darryl Philips developed a program for the F-scan which assess overall efficiency of gait, and compare pre and post orthotic treatment. The key to using the right mathematical model is to interpret the pressure data in the light of sagittal plane motion, and then correlate with specific markers showing lower extremity direction of motion.

Best,
Howard

 

Howard:

Glad you agree that the events recorded by the F-Scan can be mathematically quantified and hopefully eventually be correlated to specific mechanical events occuring within the joints of the foot and/or lower extremity. This certainly sounds very reasonable to me and could be accomplished with today's technology with, of course, adequate research time dedicated to this type of project.

In regards to the topic of "sagittal plane perturbation", I have been giving it more thought and think that it would be wise to describe these "sagittal plane blocks" or "sagittal plane perturbations" rather as alterations in the normal pattern of CoP progression which could then be caused by any number of gait phenomena, including a change in sagittal plane function of the joints. Perhaps the term "CoP progression anomaly" could be used to describe the non-normal CoP progression patterns that may include the subsets of ankle joint equinus, functional hallux limitus, early heel off, calcaneus gait, etc. Then one could describe how increases in ankle joint stiffness, or decreases in ankle joint stiffness may cause CoP progression anomalies, how functional hallux limitus or hallux rigidus may cause CoP progression anomalies, etc.

The CoP progression patterns of the force plate, pressure mat or pressure insole could then be read by the clinician in an analogous fashion to how an electrocardiogram (ECG) is read by the clinician assessing heart function: with "CoP progression anomalies" being seen when evaluating gait function being analogous to "ECG anomalies" being seen when evaluating heart function. Once these CoP progression anomalies could each be classified from research data and experimentation, then this may be able to allow in-shoe or pressure mat analysis to be accepted by the insurance industry as a standard and necessary medical expense just like ECG analysis is now accepted by the insurance industry as a standard and necessary medical expense.

 

Kevin,

"CoP progression anomaly" is a clever name for pressure analysis abberations. It is not really a description of the biomechanical alteration process as the term "sagittal plane perturbation". I am sticking with the term SPP, but will also use CoP progression anomaly to describe the pressure analysis findings.

This is actually a point have I have trying to make for a very long time. Systems like F-scan can detect an absence of weight transfer at a time when weight transfer should be peaking. It correlates precisely with the period which is referred to as late midstance pronation, and can measure when the weight transfer process has been effectively re-established. What has fascinated me over the years of using F-scan, is the subtle nature of what is necessary to accomplish improved weight transfer and still achieve a positive clinical outcome.

CoP progression anomaly is an ideal term to describe this pressure analysis abberation. Sagittal plane perturbation is the clinical term which describes the foot and postural changes which occur during the single support phase of gait.

Howard

 

Howard,

Point taken...still learning.

Thank you.

 

Hi all

I'm a fourth year Osteopathy student looking at FHL as an aetiology for LBP as proposed by Dananberg and am thinking of using it as the basis of a research proposal.

The effect Dananberg states FHL would have upon gait/posture and subsequently as a cause/contributory factor in chronic LBP seems logical, probable and acceptable BUT I have struggled to find any research that PROVES this to be true;

Dananderg's own research (chronic low-back pain and its response to custom made foot orthoses. 99') was positive in its findings but can be questioned due to the small size of the sample and the lack of a control group that might eliminate placebo effect from his results.

the only other two papers I've found (Sagittal plane blockage of the foot and ankle - prevalence and association with back pain. Gilbert. 2006) and (Sagittal plane blockage of the foot, ankle and hallux and foot alignment-prevelance and assosiation with back pain. Bratingham/Gilbert. 2006) have both FAILED to find a significant increase in incidence of LBP in people with FHL than those without when using the student t test to determine what constitutes significant difference.

I cant quite believe the research in this area would be so sparse - If anyone can help with some pointers it would be much appreciated!

Josh

p.s. honorable mention to vegetableplots for starting the conversation, I hope I'm not standing on your toes by posting here!