It seems that the words boot camp, Low gear and high gear have popped up in threads a lot over the last couple of days.
Members do not see these Ads. Sign Up.
Is the work of Bojsen-Moller having a renascence of sorts - ie the new/old black ?
anyway for those who want to read some of his stuff, heres some links for you
http://informahealthcare.com/doi/pdf/10.3109/17453677908989792
http://www.podiatry-arena.com/podiatry-forum/showpost.php?p=172953&postcount=5
Happy reading
Tags:
-
-
Bojsen-Moller's idea that there is possibly a "high-gear" or "low-gear" for propulsion in the human foot is an interesting one. However, I believe this idea of a "high-gear" or "low-gear" propulsion oversimplifies the complex processes occurring during late-midstance and propulsion that may cause propulsion over either the medial or lateral forefoot.
Factors such as the prevailing subtalar joint (STJ) moments during late-midstance and propulsion, medial column vs lateral column dorsiflexion stiffness, relative length patterns of the metatarsals (i.e. metatarsal parabola), angle of gait and muscle strength may all influence whether the medial or lateral metatarsal heads are more involved in propulsion. I really can't see that using Bojsen-Moller system of classifying propulsion into two types is really any better than those clinicians that recommend "foot-typing classification systems" where they pigeon-hole feet into discrete anatomical classifications which may or may not have any correlation to foot function or foot and lower extremity pathology.
I have never used Bojsen-Moller's ideas in any of my lectures (that I can remember), don't intend to but think that they may deserve historical mention by some lecturers. However, I don't think these ideas really belong in any state-of-the-art podiatric biomechanics lectures. I am not that sure that his ideas have helped me in any way to better understand foot function. -
When you see the wear on an insole of a shoe from fifth met head through second to IPJ of the hallux, what does that indicate that is happening to the forefoot loading during propulsion?
__________________ -
Wear on an insole generally indicates the insole is receiving significant compression force from the plantar foot. Maybe you can elaborate further?:confused: -
See attached doc. 5th met to first ipj = low gear
1st met through second met = high gear
Perhaps! -
Kevin,
See attached doc. 5th met to first ipj = low gear
1st met through second met = high gear
Perhaps!Attached Files:
-
-
we really need Henenfeld's papers here to get a full historical, if anyone could oblige I'd be eternally grateful. Eric Lee sent me photocopies of these papers many years ago, I know I no longer have them.
http://www.ncbi.nlm.nih.gov/pubmed/13053183
http://www.ncbi.nlm.nih.gov/pubmed/13053190 -
Although I'm sure they could be explained by a whole number of other principles. MASS perhaps. In fact, I bet if you look at the forefoot wear after wearing a MASS device you would very clearly see a "low gear" pattern. - perhaps -
Like you said, perhaps these insoles indicate a "low-gear pushoff". Maybe, also, these insoles demonstrate a functional hallux limitus, structural hallux limitus/rigidus or some other pathology since shoe insole impressions don't allow us to see the temporal patterns of ground reaction forces in the forefoot. An in-shoe pressure measurement system, such as F-Scan, would give you much more data that would allow a better classification of propulsion types in individuals. -
-
This is where 'current concepts in podiatric biomechanics' becomes difficult. Having sat through a couple of days listening to Craig's summarisation in the Boot Camp - of how the various axis determine the efficiency of low gear and high gear propulsion - and appreciating the logic - then reading this interprettion and also appreciating its logic, one is left with the overwhelming urge to inset the cranium into the microwave and cook on full power for 30 mins in the hope that whatever is left can make sense of it all. One thought though - if MASS orthotics aim to promote the foot to function in a supinated position primarily, doesn't that mean that function revolves around the low gear hypothesis - ergo; the least effective and/or optimal position for propulsion? :bang::bang::bang:
-
Bojsen-Mollers hypothesis is just that. A hypothesis. IMHO, a very good hypothesis. It does explain a lot of observations and research on foot function.
Maybe the use of the terminology of "high" and "low" gear as analogous to the gears in the car is problematic. Perhaps the focus and terminology should be on the length of the lever arm to the oblique and transverse axes. -
-
Have to say that I have been smiling and laughing uncontrollably at times at seeing you, Eric, Robert, Graham and Michael all taking big bites out of The Turkey over the Thanksgiving holiday...you know who I mean.:rolleyes:
Anyway, back to Craig's take on low-gear and high-gear. I agree with you that analyzing the center of pressure (CoP) makes a lot more sense than even trying to pidgeon hole the latter half of stance phase as being either "high-gear" or "low-gear". Certainly we would want to be able to classify the movement of ground reaction forces during the latter half of stance phase into more than just two categories, "low-gear" and "high-gear". I would think position of CoP relative to the ankle joint axis, subtalar joint axis and Achilles tendon would give us a more better idea of the kinetics of the latter half of stance phase than using Bojsen-Moller's "low-gear, high-gear" approach. -
-
That's the thing about turkeys - they often like to claim that they're really something else even when it's patently obvious that they're not.... ;)
Attached Files:
-
-
This is interesting from the Nigg paper Ian linked to here: http://www.podiatry-arena.com/podiatry-forum/showpost.php?p=182059&postcount=26
"Bojsen-Moller (1977) indicated that the MP joints rotate
about a transverse axis for sprinting but an oblique axis
during running. During running, the more anterior positions
of the MP axis at the center and medial side of the
foot would shorten the lever arm of the external ground
reaction force and, therefore, reduce the calculated MP
torque. The extent of the error associated with assuming
a transverse axis would depend on the individual anatomy
of the subjects. However, as was seen by the sensitivity
analysis, an average anterior shift of the MP axis by
1 cm resulted in an average decrease of 27% in the energy
absorbed at the MP joint during running."
Loading...
- Similar Threads - Bojsen Moller low
-
- Replies:
- 59
- Views:
- 71,295