Post by robertisaacs on Jan 16, 2008 10:20:38 GMT
Ah brian. I reach for the neurofen whenever i see your posts. You always make me question why i think what i think. Which, i suppose is healthy.
I'd like to examine one in particular. Of the models you present in particular.
Funky gif BTW
Several questions.
1. You say that the pronation in the right foot elevates the right acetabulum and tilts the pelvis to the right the x ray however shows the left side of the pelvis to be higher (more cephalad). This would fit with Bill sanners work( A study of ankle joint height changes with subtalar joint motion
J Am Podiatr Med Assoc 1981 71: 158-161. ) Which indicates that stj pronation can result in a functional shortening of over 10mm.
Which is it? How can pronation both shorten the leg and elevate the acetabulem? How can the acetabulem be elevated and yet the right hand side of the pelvis dropped?
2. YOu say when the feet are vertical you say the hips function in their neutral position. Given that in the vast majority of feet the STJ functions in a pronated range (proposed as being "normal" if it is between neutral and 3 degrees from maximal pronation,) KA Kirby
Biomechanics of the normal and abnormal foot
J Am Podiatr Med Assoc 2000 90: 30-34. what does this tell us about how much time the hips are designed to spend in their "neutral position".
3.
I read your 2006 japma paper on LLDs and pronation with interest and a little confusion. For the benifit of those of us who are a little slow perhaps you would clarify a few points.
Again i am confused. If pronation shifts the innominates cephalad would that not mean the pelvis would tilt with the pronated side higher than the other side resulting in a functional LENGTHENING of that leg?
If you are extrapolating this data from an observed shortening of the leg on static WB what makes you think that the shortening is caused by the positioning of the hips and not the aforementioned shortening at the distil end of the leg.
Agreed
You don't make it entirely clear what landmarks you use for the discrepancy in FLLD as you do in ALLD. Would you say that a FLLD can be measured as the shortening between the head of the femur and the considering that we function from the soles of our feet rather than from our ankles? From the pelvis to the ground? From the pelvis to the malleoli?
Regards
Robert
(ps, for the sake of my liver could we have your reply with short words please! We're not all as conversant with upper body anatomy and posturology as you!)
I'd like to examine one in particular. Of the models you present in particular.
Funky gif BTW
Several questions.
1. You say that the pronation in the right foot elevates the right acetabulum and tilts the pelvis to the right the x ray however shows the left side of the pelvis to be higher (more cephalad). This would fit with Bill sanners work( A study of ankle joint height changes with subtalar joint motion
J Am Podiatr Med Assoc 1981 71: 158-161. ) Which indicates that stj pronation can result in a functional shortening of over 10mm.
Which is it? How can pronation both shorten the leg and elevate the acetabulem? How can the acetabulem be elevated and yet the right hand side of the pelvis dropped?
2. YOu say when the feet are vertical you say the hips function in their neutral position. Given that in the vast majority of feet the STJ functions in a pronated range (proposed as being "normal" if it is between neutral and 3 degrees from maximal pronation,) KA Kirby
Biomechanics of the normal and abnormal foot
J Am Podiatr Med Assoc 2000 90: 30-34. what does this tell us about how much time the hips are designed to spend in their "neutral position".
3.
I read your 2006 japma paper on LLDs and pronation with interest and a little confusion. For the benifit of those of us who are a little slow perhaps you would clarify a few points.
These results are consistent with a theoretical ascending dysfunctional pelvic model: Abnormal pronation pulls the innominate bones anteriorly (forward); anterior rotation of the innominate bones shifts the acetabula posteriorly and cephalad (backward and upward); and this shift in the acetabula hyperextends the knees and shortens the legs, with the shortest leg corresponding to the most pronated foot.
Again i am confused. If pronation shifts the innominates cephalad would that not mean the pelvis would tilt with the pronated side higher than the other side resulting in a functional LENGTHENING of that leg?
If you are extrapolating this data from an observed shortening of the leg on static WB what makes you think that the shortening is caused by the positioning of the hips and not the aforementioned shortening at the distil end of the leg.
Anatomical leg-length discrepancy is defined as a structural discrepancy between paired limbs. A physical shortening has occurred between the head of the femur and the ankle mortise of one limb compared with the other
Agreed
Functional leg-length discrepancy is defined as an apparent discrepancy between paired limbs without a concurrent measurable difference
You don't make it entirely clear what landmarks you use for the discrepancy in FLLD as you do in ALLD. Would you say that a FLLD can be measured as the shortening between the head of the femur and the
ground
Regards
Robert
(ps, for the sake of my liver could we have your reply with short words please! We're not all as conversant with upper body anatomy and posturology as you!)