Hello List,
From the 19 responses, 17 were likewise knowing Wolff, but not Davis. The other two knew both.
Of the two people who knew of Davis, one professionally presented on soft tissue interventions and the other clarified it as something discussed in the context of traction. Kudos to both of them for retaining something that may or may not have been appropriately covered in our normative learning process.
My thoughts:
Normative is the learning gained in formal academic setting. I’ve learned a terrific word to balance it: Heuristic. That’s the knowledge… the learning… that we clinicians obtain from decades of real life experience. It is the pragmatic knowledge of the self-taught. It is the knowledge retained from rubber meeting road. I believe that appropriate respect is given by those with great heuristic learning (smart practitioners) to those whose knowledge is derived from normative methods (professors). Unfortunately, I believe that the possibility of superiority of heuristic input is too easily dismissed in the world of academia’s normative learning mindset… and it is to their detriment.
So… until any clinician from another profession has decades of fitting sockets under his or her belt? You can claim no rubber nor road. Any intrusion into our scope of practice without our equitable authority during collaboration has a high likelihood of flaws and complications…
Davis’ Law complicates things. Research shows us that functionally limiting contractures can develop in merely two weeks. This means that the static alignment of our components can be less than optimal with the altered alignment of the patient’s ligaments after a simple bout with pneumonia. If you don’t have a focus on soft tissues, and this is certainly the case in the field of biomechanics that focuses on bones (and perfect soft tissues that allow such perfect joints to work together in perfect perfectness…), you only have a partial view of true causes and effective solutions. In short, you’re missing something and don’t even realize it.
Examples of this? Fair challenge. I would give you triceps surae, a very fancy word for a horrible oversight where two completely different soft tissues (gastroc and soleus) are blended into a single structure simply by virtue of both of them having a common insertion via the achilles tendon. Change the achilles surgically and have two highly different and separate manifestations as a consequence. …oops, you just prevented your patient from ever being able to walk downhill. Or how about removing the TFL/IT band during TF amputation surgery? Did you know that the architect of this surgery also claims that the TFL/IT band is the primary abductor of the hip in a journal just 5 years earlier? So, which is true?… since only one can be… Or how about having the head of a kinesiology department at a major university admit that they don’t really understand the true nature of the TFL/IT band? …hey, it’s his textbook that is used in some of our O&P programs (and yes, I have his admission in an email)… or a biomechanics lab that admits that they still don’t understand where 33% of ankle power comes from? How can they admit that and still move forward to publish with confidence?
So? How did I do with examples?
Seems like Davis’ Law deserves an equitable seat at the table with our buddy Wolff.
Partial solutions… none of which will be resolved by pressing into an ever more convoluted future seeking to justify higher reimbursements… perhaps the best way to move forward is to turn to the past and first examine our foundational assumptions. It’s like the Mark Twain quote that opens the movie “The Big Short”: “It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so.”
The ironic part? Mark Twain never said it… and so, fellow prosthetists and orthotists… much of the claims we may hear at a conference regarding OI and surgery and biomechanics and gait? Well, let’s simply say that much of it… “just ain’t so.” It’s because they need a little help from the heurists. Hopefully having Davis’ status of being a “law” and not subordinated to Wolff’s law will help you to better collaborate on equal footing with others.
Have a terrific week and give ‘em hell.
Tom
PS: Regarding TF amputation surgery, see Gottschalk 1989, pg 182-184 for TFL importance. For TFL/IT band removal, it’s Gottschalk 1994, pg 16, column 1, sentence starting with “however…”. Mind you, there is a third option with regard to which is right… and that is “none of the above”… that both are actually wrong. *chuckles*… but that’s not really possible, right? I mean, in The Big Short, nobody bets against the housing market, do they?
Original post—-
Hello List,
After being invited to co-author an article with an orthopedic surgeon on equinus contractures, I’m taking a quick pulse on a possible angle for the article.
A single question:
Do you recall Wolff’s Law and also recall Davis’ Law?
If you respond with “Wolff, yes, Davis, no”, that would be the same as my answer.
Or… “Wolff, vaguely. Davis, no” might be more accurate, since this goes back more years than I care to admit…
FYI: Wolff says that bones respond structurally to the forces we put on them. Davis says the same thing, only for soft tissue like ligaments and tendons. We are all very familiar with contractures, etc, but being able to quote Davis’ Law carries weight. I was frankly surprised that I was only aware of Wolff. Is this (relative) unfamiliarity with Davis’ Law the same for other practitioners as it was for me?
With everyone’s busy schedules, I appreciate the feedback. I think that unfamiliarity with contractures results in assumptions that a problem lies in the orthosis or prosthesis rather than in the natural consequence of the rules of Davis’ Law.
So… Wolff? Davis?…
Thanks in advance,
Tom
Thomas J. Cutler, CPO, FAAOP
Limb.itless, LLC
113 N. Church Street
Suite 312
Visalia, CA 93291
559-334-3741 phone
559-553-8837 fax