Welcome to the Podiatry Arena forums

You are currently viewing our podiatry forum as a guest which gives you limited access to view all podiatry discussions and access our other features. By joining our free global community of Podiatrists and other interested foot health care professionals you will have access to post podiatry topics (answer and ask questions), communicate privately with other members, upload content, view attachments, receive a weekly email update of new discussions, access other special features. Registered users do not get displayed the advertisements in posted messages. Registration is fast, simple and absolutely free so please, join our global Podiatry community today!

  1. Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
    Dismiss Notice
Dismiss Notice
Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
Dismiss Notice
Have you liked us on Facebook to get our updates? Please do. Click here for our Facebook page.
Dismiss Notice
Do you get the weekly newsletter that Podiatry Arena sends out to update everybody? If not, click here to organise this.

STATISTICAL NORMAL FOOT vs MOST EFFECTIVE FOOT

Discussion in 'Biomechanics, Sports and Foot orthoses' started by fabio.alberzoni, Nov 28, 2017.

  1. fabio.alberzoni

    fabio.alberzoni Active Member


    Members do not see these Ads. Sign Up.
    Hi all!
    It's a long time I'm learnig that pronation is not evil and is important for many reasons.
    Ok, we have to leave behind our dear and loved M. Root.
    We are now looking more at studies which shows that the majority of feet are pronated. I really think that is nothing of new.

    I feel that in this way if the majority of people would begin to walk backwards it were considered normal.
    NORMAL: I hate that word!

    The evolution in the past (i.e. Darwin's Theory) brought all the races and animal species to improve their DNA encouraging the best specimens.
    NOWADAYS: the society (in rich countries as european or north america) is encouraging the reproduction of people cause of their religion more than phisical skills.
    Are we sure that this statistic normality describes the best feet are present in nature? I think not.
    I think that for sure we OVERTREATED pronation in the past, but my clinic is full of old people who never was treated even if they had bad biomechanical conditions.
    Well, they often have Hallux Rigidus, Hallux Valgus, Hallux limitus, Splay foot ect ect...
    does exist an ideal model? Which is the the best alignment that you all consider for a surgical approach?
    what's nowadays important in foot deformities and pathologies' prevention?

    Please someone lights my dark and stubborn lack of understanding.
    Cheers,
    Fabio​
     
  2. efuller

    efuller MVP

    You touch on a couple of issues. One is evolution of the human foot. I would say that your car might be more important than your feet in the ability to reproduce. Certainly you are not going to buy a minivan until after you have kids. The minivan is much more helpful in propagating your DNA after you have kids.

    The other issue is when to treat an aymptomatic foot in order to prevent future problems. Take high blood pressure. We know that there are future problems that can be prevented by lowering high blood pressure. What measures do we have in the foot that are predictive of future pathology. It used to be thought that "pronation" was something that predicted future pathology. However, some people talk about a pronated foot without even looking at STJ motion. How do we measure pronation and does that measure correlate with future pathology. The foot posture index is an attempt to look at what some people call pronation. So, does that correlate with pathology?

    If we knew that a measure was predictive of pathology we would then need to know that a treatment prevented that pathology. Beta blockers lower blood pressure. What alters the foot posture index? Is the foot posture index something that lends itself to a treatment. On the other hand STJ axis position makes a lot of sense as a possible predictor of pathology. I wonder how well foot posture index correlates with STJ axis positon. The STJ axis position can be correlated with the direction and magnitude of moment of ground reactive force acting on the STJ. So, we need some research showing at what STJ axis position the cost of treatment is worth the prevention of pathology. Then we could treat the extremes of STJ axis position proactively.
     
  3. Fabio:

    In addition to Eric's excellent comments, I believe that the kinematics and kinetics of gait are very important in producing pathology and are probably much more predictive of future pathology than any static foot measurements available to us.

    I do agree with Eric that subtalar joint (STJ) axis spatial location will eventually be found to be somewhat predictive of some types of pathology, especially in its extremes, but don't think that mild variations in STJ axis spatial location will necessarily be predictive of pathology since the human central nervous system (CNS) is very good at adapting to slightly abnormal external moments from ground reaction force acting across the STJ during standing and walking. The role of the CNS is still the "great unknown" for us in regards to foot biomechanics and I am hoping that further work with fine wire EMG, such as the excellent recent research by Luke Kelly and coworkers on plantar intrinsic muscle function, will shed much more light on how the CNS interacts with the foot to optimize gait, avoid pain and efficiently perform weightbearing activities. Wouldn't it be nice to see a fine wire EMG study of the posterior tibial and peroneal muscles in patients with posterior tibial tendon dysfunction with and without custom foot orthoses??

    Even though I have great respect for the work of Merton Root, I believe his decision to call his "ideal foot" the "normal foot" was one of his biggest mistakes. The second biggest mistake of Merton Root was to ignore the talar head position and focus only on calcaneal bisections to determine STJ kinetics. It is interesting, that on the East Coast of the USA, Richard Schuster was supposedly a big believer on the importance of talar head position, but he never wrote anything about it so his thoughts were lost when he passed away. The calcaneal bisection is simply a poor predictor of pathology, and Mert Root relied much too heavily on that measurement parameter which was a big mistake. Had he considered the kinetics of STJ axis location, using the talar head position, and not been so focused on calcaneal bisections, which are useless in determining STJ kinetics, he would have gone farther. Manter, and Isman & Inman both published their STJ axis research before 1970, well before Root and colleagues started publishing their books on foot biomechanics.

    In regard to preventing future pathology, in a perfect world, we would have unlimited financial resources to study each person's foot and lower extremity biomechanics, do MRI scans, CT scans, 3D gait analysis and in-shoe pressure measurement to see if their feet and lower extremities were "within normal limits" or had some structural or functional variation which could lead to future pathology. Even then, trauma, shoes, or neurological disorders and sports activities could alter the course of pathology development. A large-scale, 50-60 year study of foot function/pathology would be necessary to see if congenital foot structure predicted pathology. I don't see that happening anytime soon.

    In the mean time, the ethical biomechanically-minded podiatrist should carefully observe and note the foot structure and foot and lower extremity biomechanics of their patients and advise them on whether they think foot orthoses (either pre-made or custom) would be beneficial for their patients over the long term. Just because the research isn't there yet showing that foot orthoses can prevent pathology, certainly if the foot orthoses can normalize gait function for patients with abnormal gait patterns, this is good enough justification, in my mind, to suggest foot orthosis treatment to hopefully help prevent future problems from occurring in our patients over their lifetimes.
     
  4. Petcu Daniel

    Petcu Daniel Well-Known Member

    Seems to me that "abnormal gait patters" as opposite to "normalize gait function" is, at the end, in the same relation as "normal foot" with "abnormal (?) foot". In the first case is about a process while in the second is about a morphology. Why it should be normalized an asymptomatic abnormal gait pattern? What if instead of "normalize gait" we will use "optimize gait"? How the asymptomatic flatfoot's function could be optimized? And how this will change the evaluation of the effectiveness of foot orthoses? It is somehow similar with the reduction of the pathological stress in a tissue. We don't have clear values (numbers) for how much the reduction has to be but the process of decreasing related to positive patient's outcomes is what it counts.

    Daniel
     
  5. fabio.alberzoni

    fabio.alberzoni Active Member

    @eric fuller
    thanks eric for your answer!

    EVOLUTION:

    "your car might be more important than your feet" :it's the same I'm saying....I mean 200 years ago or in africa maybe the effectiness of the foot can help you to survive to hunt, to grow vegetables ect ect. The more you hunted the more important you was....and obviously richer and with more possibilities to have sons. Animals have a better evolution cause the faster they run the more they live. In humans the function of the foot doesn't have a role in evolution.
    Anyway also saint Peter had flat foot 2000 years ago...like the next pic shows.

    21740155_2020869554808844_4403455820089019570_n.jpg
    Unfortunatly he dies on a cross head down when he was probably 65. No case report about his forefoot or rearfoot deformities.
    People nowadyas survives until 100 yo more commonly that in the past. Prevention is becoming more and more important.

    That's the point!

    By now I only read an articole suggested by Craig Payne about how lunge test could predict pathologies.
    Honestly, I hate the foot posture index...too much time for a useless number.
    I don't even use Root calculation.I don't correct inverting the orthesis of 5° for each degree of pronation like Blake said in the past.
    My idea is to try to understand which structures could have the biggest internal load/overload.

    In these days I'm treating almost only painful feet. Honestly I would bet that many feet that I didn't treat will have problems.

    you said "Then we could treat the extremes of STJ axis position proactively."...for me: good point, but only a start. Anyway rely prevention on excessive STJAL medialization is not so far from treating ecxessive pronation.
    I'm beginning observing more QOM(quality of motion) than ROM. Let you know if I 'll begin to understand better if is linked with pathologies.

    cheers,
    fabio
     
  6. scotfoot

    scotfoot Well-Known Member

    As the age distribution pyramid in modern societies becomes increasing top heavy so the foot and conditions which affect it become more important for those of all ages .
    Morbidities affecting the foot and other debilitating disorders in the elderly might have more of an impact on how many children families can afford than you might at first think .
     
  7. You can only treat what is in front of you. Everyone has their own pathological window which is always moving. Looking at famlar traits may the only real way to look at treating to "prevent" problems with a slightly higher chance, but I don´t think about abnormal or normal much these days - how can we if we don´t know how much stress the body can take

    N = 1
     
Loading...

Share This Page