kinetic chain

[dtt]

I Agree David

Could we not have a personal section on the site for jokes & other silliness preferably away from public gaze in the registered member section??

The banter could then continue for those that want to and the more serious discussion can continue uninterrupted.

Perhaps it would be possible to edit the stuff from here to there ??
Just a thought

Cheers
Derek

[twirly]

Sorry

Best behaviour from now on.

twirly

[robertisaacs]

Could we not have a personal section on the site for jokes & other silliness preferably away from public gaze in the registered member section??

The banter could then continue for those that want to and the more serious discussion can continue uninterrupted.

The people have spoken David. We need us a break room / anything goes section. Brains work better when they have chance to let off steam.

Dragging the topic back.

Does anyone know of any papers which offer kinematic data on the rotation of the femur (not the position of the pelvis) during gait and the effect of orthotics on said rotation.

I ask because although i accept the effect of orthotics on the upper body i am starting to question the traditional kinetic chain model of HOW they have that effect. (HERESY HERESY, BURN THE WITCH).
Whilst i am not yet ready to accept brians model of hypertonicity wholesale i am wondering what the effect of othotics, any orthotics, on core stability muscle tone. I am also wondering if there is something awfully clever and sagital plane going on.

Here's a ponderable. All of the studies i have read on orthotics involve supplying somebody with orthotics ("well Duh" i hear you think....bear with me, i am going somewhere with this). If you introduce a kinetic / kinematic change to somebody they will react in terms of the sensation of those devices. The whole IMH / IBH thing. Could it be that all our data has been skewed by the bodies response to the "newness" and "differentness" of the devices?

Put another way how many times have you given somebody orthotics and watched them walk out like they're in diving boots?

If the effect of the orthotics changes with time how do we account for that?

I feel another research proposal coming on!

Regards
Robert

[deekay38]

Robert

Can you accept that sagittal plane changes are seen when orthoses are fitted. Dananberg and Gelhuwe, as you know, have several papers demostrating this.

I would say that these days the main focus of my orthotic prescription for most customers if sagittal plane progression facillitation. I always start with ankle Mobs to increase Dorsiflexion RoM where required.

However if one made an orthosis with a 25dg full length medial ramp, I think changes in the kinematics of the limbs distal to the foot would be obvious.

Where would the point be where a frontal plane posting intervention would be small enough to make no difference to the kinematics distally?

Kinetically speaking if the orthoses change the application of GRF to the foot then this will also change the internal kinetic reaction. If one muscle changes its tension characteristics it would be safe to assume that a whole chain of muscles and connetcive tissues must change also. This has been called reciprocal anatgonism / synergism. This is brought about by the fact that a joint is not moved thru a certain angualr displacement by one muscle alone.
There are primary and secondary muscular actions in respect to the angular displacement of interest. This gives the advantage of built in redundancy. This also leads to a complicated action and reaction sequence of events that is difficult to model. However if you appreciate that muscles tend to pull obliquely to the joint then there are sine and cosine forces that must be balanced by some other muscle. This in turn has a sine / cosine action that requires balancing and so on. When the muscle crosses a joint or is bi or multi articular (as in the foot) the flexing effect on one joint has an unwanted extendsion effect on a corresponding joint and there has to be a reciporacle action by some other muscle. This action reflects back to the original muscular action and around it goes again.

So you may see that changing kinetics at the foot could have far reaching effects thru the whole body even if the kinematics of the foot are apprantly unchanged.

I agree that many changes may also be due to the neuromuscular reaction to extrinsic stimuli produced by the orthosis. This is clearly and immediately obvious in antalgic response.

I haven't come across the terms IMH / IBH that you use, can you give a reference, I'de like to read up.

Cheers Dave

[dtt]

Hi Dave

the flexing effect on one joint has an unwanted extendsion effect on a corresponding joint and there has to be a reciporacle action by some other muscle. This action reflects back to the original muscular action and around it goes again.

I agree, and to put it another way if one joint is is functioning incorrectly the joint immediately above will compensate in some way.

As with any treatment affecting a primary muscle will also have an effect on its antagonist.

I hope you are coming to "the meet at Martins" ?? Coz I would love to go through this in practical terms with you and Robert and discuss my way

Cheers
Derek

[dtt]

Hi Robert

I ask because although i accept the effect of orthotics on the upper body i am starting to question the traditional kinetic chain model of HOW they have that effect.

The answer I have given Dave will help I think

If the effect of the orthotics changes with time how do we account for that?

Because a balance is struck over time with muscle equalibrium ( primary /antagonist) and ROM restoration in joints ?

Just my thoughts

Cheers
Derek

[robertisaacs]

Hey dave. Nice to see you here.

Can you accept that sagittal plane changes are seen when orthoses are fitted. Dananberg and Gelhuwe, as you know, have several papers demostrating this.

Yes.

However if one made an orthosis with a 25dg full length medial ramp, I think changes in the kinematics of the limbs distal to the foot would be obvious.

Where would the point be where a frontal plane posting intervention would be small enough to make no difference to the kinematics distally?

Well thats the real question is'nt it. As you say if i put a 25 degree through wedge or fully adduct or abduct my feet in static i can observe a proximal response.

However we don't do that do we? And the literature does not indicate that the standard range of orthotics cause a large frontal plane response (if any). And thats before any motion is lost by the translation into transverse plane rotation. Which i suppose is why its called the kinetic chain not the kinematic chain. Which brings us to...

Kinetically speaking if the orthoses change the application of GRF to the foot then this will also change the internal kinetic reaction. If one muscle changes its tension characteristics it would be safe to assume that a whole chain of muscles and connetcive tissues must change also.

Agree with reservations. The reservations being that depending on the nature of the upper body "change" being observed there has to be a switch from a kinetic to a kinematic change somewhere along the line.

This has been called reciprocal anatgonism / synergism. This is brought about by the fact that a joint is not moved thru a certain angualr displacement by one muscle alone.
There are primary and secondary muscular actions in respect to the angular displacement of interest. This gives the advantage of built in redundancy. This also leads to a complicated action and reaction sequence of events that is difficult to model

.

Difficult to model. No kidding. And i've seen some of your models . The concern I have is that when it is so difficult to model a sequential "chain" with linked components how can we be sure that there is a "chain" as opposed to a more direct effect.

However if you appreciate that muscles tend to pull obliquely to the joint then there are sine and cosine forces that must be balanced by some other muscle. This in turn has a sine / cosine action that requires balancing and so on. When the muscle crosses a joint or is bi or multi articular (as in the foot) the flexing effect on one joint has an unwanted extendsion effect on a corresponding joint and there has to be a reciporacle action by some other muscle. This action reflects back to the original muscular action and around it goes again.

Well put. You usually manage to make these things clear (after reading what you've said 12 times). I can imagine this working in the saggital plane where the lever arms are long enough to make it work. But the frontal plane / transverse plane idea that the pelvis is tilted upwards (whatever the posh way of saying that is) by the rotation of the leg? Can't see it. Thats a kinematic chain.

I agree that many changes may also be due to the neuromuscular reaction to extrinsic stimuli produced by the orthosis. This is clearly and immediately obvious in antalgic response.

Agreed. I think this is a much underestimated variable.

I haven't come across the terms IMH / IBH that you use, can you give a reference, I'de like to read up.

Can't give a ref for that because as i described earlier in the thread its just my own shorthand. I use IMH for Iatrogenic malignant hypertonia, when i issue an insole and the patient never psychologically accepts it. As such they hold their foot in a conciously controlled position and get sporadic and varied pains in the exstrinsic muscles around the legs and feet as a result.

regards
Robert

[dtt]

Hi All

Sorry to interject again but

Robert

But the frontal plane / transverse plane idea that the pelvis is tilted upwards (whatever the posh way of saying that is) by the rotation of the leg? Can't see it.

If the pelvis is tilted "upward" is that not a saggital plane
motion ?

As you say if i put a 25 degree through wedge or fully adduct or abduct my feet in static i can observe a proximal response

Would you not be then everting the feet with the wedge which will promote extenal rotation of the tibia and femur in a transverse plane and the pelvis in a saggital plane motion by tilting the pelvis upward ?

The concern I have is that when it is so difficult to model a sequential "chain" with linked components how can we be sure that there is a "chain" as opposed to a more direct effect.

Because the joint above compensates for the joint below and that works upwards throughout the skeletal system.

As such they hold their foot in a consciously controlled position

Coo that's a goodun

So the patient is taking over control of proprioceptive action then ??

Sorry cant have that one either ( roll on January ;D )

Cheers
Derek

[blinda]

Ok....so practically speaking, what can i bring to the table? Is there any suggested reading i can swot up on?

Cheers,
belinda

(PS Twirly.....So cunning you could put a tail on it and call it a weasel!)

[dtt]

Hi Blinda

Just bring yourself , your input ( no swotting required, as you feel will do) and enthusiasm for what is looking like a great weekend ;D

And err just a point ,our leader has decreed no banter on the main topics ( go to registered member section / martins Doo, or break room, Shhh) ;D

Cheers
Derek

[robertisaacs]

But the frontal plane / transverse plane idea that the pelvis is tilted upwards (whatever the posh way of saying that is) by the rotation of the leg? Can't see it.

If the pelvis is tilted "upward" is that not a saggital plane
motion ?

Yes. Emphasis of IF. What i dispute is the kinematic link between frontal plane modification in an orthotic - transverse plane rotation of the femur - sagital plane tilting in the pelvis. I know that that can technically be said to be the relationship based on gross movements, however there is little evidence of very much frontal plane effect above the STJ from orthotics and still less of the further links in the chain.

As you say if i put a 25 degree through wedge or fully adduct or abduct my feet in static i can observe a proximal response

Would you not be then everting the feet with the wedge which will promote extenal rotation of the tibia and femur in a transverse plane and the pelvis in a saggital plane motion by tilting the pelvis upward ?

Yes. But thats with a 25 degree through wedge! my point is that the evidence does not support this with orthotics at the type of levels we generally use.
In the boot clinic i do with the orthotist and the physio we do lots of work with intoer's and outtoers. The devices we are using are things like hip twisters and full on AFOS (SAFO's, SMAFO'S,DAFO'S, GRAFO's, KAFO's etc. What is it with orthotists and FO's?). And even then it is damn hard to have an observable effect. Now i know these are mostly neurological patients but still!

The concern I have is that when it is so difficult to model a sequential "chain" with linked components how can we be sure that there is a "chain" as opposed to a more direct effect.

Because the joint above compensates for the joint below and that works upwards throughout the skeletal system.

Theoretically. But what a big word is theoretically! That assumption that the change cascades up the body is fine if you accept that there is no "loss of signal" so to speak.

Put another way. Brians work on infertility is based on a logical progression. Control the pelvis (via whatever mechanism) you decompress the uterus. Decompress the uterus you increase blood supply. Increase blood supply, good things happen. There is a logical process there. I just question whether the magnitude of forces/movements we effect is sufficient.

As such they hold their foot in a consciously controlled position

Coo that's a goodun

So the patient is taking over control of proprioceptive action then ??

Sorry cant have that one either ( roll on January )

Ok, don't have that one. 8-)It was only my shorthand not something i'm trying to "sell". Not sure you you mean by proprioceptive action but i see no problem with conciously holding one's foot in a certain way.

Tell you what. Walk a mile concentrating on, say, the position of your mid tarsal joint in your shoe. Have a crack at keeping your navicular from resting to much on you orthotic (i bet you've got one!). The feeling you get in your legs and ankles afterwards? Thats what i'm talking about.

Regards
Robert

[robertisaacs]

Aha! I have found research which backs my contention ;D

Insoles for prevention and treatment of back pain.
Sahar T, Cohen M, Ne'eman V, Kandel L, Odebiyi D, Lev I, Brezis M, Lahad A.
Cochrane Database Syst Rev. 2007 Oct 17;4:CD005275.

Quote:
BACKGROUND: There is lack of theoretical and clinical knowledge of the use of insoles for prevention or treatment of back pain. The high incidence of back pain and the popularity of shoe insoles call for a systematic review of this practice. OBJECTIVES: To determine the effectiveness of shoe insoles in the prevention and treatment of non-specific back pain compared to placebo, no intervention, or other interventions. SEARCH STRATEGY: We searched the following databases: The Cochrane Back Group Trials Register and The Cochrane Central Register of Controlled Trials (CENTRAL) to March 2005, and MEDLINE, EMBASE, and CINAHL to February 2007; reviewed reference lists in review articles, guidelines and in the included trials; conducted citation tracking; contacted individuals with expertise in this domain. SELECTION CRITERIA: We included randomized controlled trials that examined the use of customized or non-customized insoles, for the prevention or treatment of back pain, compared to placebo, no intervention or other interventions. Study outcomes had to include at least one of the following: self-reported incidence or physician diagnosis of back pain; pain intensity; duration of back pain; absenteeism; functional status. Studies of insoles designed to treat limb length inequality were excluded. DATA COLLECTION AND ANALYSIS: One review author conducted the searches and blinded the retrieved references for authors, institution and journal. Two review authors independently selected the relevant articles. Two different review authors independently assessed the methodological quality and clinical relevance and extracted the data from each trial using a standardized form.

MAIN RESULTS: Six randomized controlled trials met inclusion criteria: Three examined prevention of back pain (2061 participants) and three examined mixed populations (256 participants) without being clear whether they were aimed at primary or secondary prevention or treatment. No treatment trials were found. There is strong evidence that the use of insoles does not prevent back pain. There is limited evidence that insoles alleviate back pain or adversely shift the pain to the lower extremities.LimitationsThis review largely reflects limitations of the literature, including low quality studies with heterogeneous interventions and outcome measures, poor blinding and poor reporting.

AUTHORS' CONCLUSIONS: There is strong evidence that insoles are not effective for the prevention of back pain. The current evidence on insoles as treatment for low-back pain does not allow any conclusions.High quality trials are required for stronger conclusions.

A single-blind pilot study to determine risk and association between navicular drop, calcaneal eversion, and low back pain.
Brantingham JW, Adams KJ, Cooley JR, Globe D, Globe G.
J Manipulative Physiol Ther. 2007 Jun;30(5):380-5.

Quote:
OBJECTIVE: Syndromes causing mechanical low back pain (MLBP) continue to plague the US health care system. One hypothesis is that flatfeet are a risk factor for MLBP. This pilot study evaluated whether subjects with flatter feet are at greater risk for MLBP than subjects without flatter feet.

METHODS: Fifty-eight subjects (16-70 years old) were allocated to a group diagnosed with 2 or more episodes of MLBP or with no history of MLBP. A blind assessor measured navicular drop (ND) using navicular height (NH) and calcaneal eversion (CE). Based on a range of reported data, flatfoot was defined as a possible risk factor for MLBP with ND greater than 3, 8, and/or 10 mm, and/or greater than 6 degrees CE.

RESULTS: According to chi2 analysis, risk of MLBP appeared similar between groups (P > .05). There was no significant difference (P > .05) between continuous variables (t tests, Pearson r and r2) with one exception, correlation of increasing CE with increasing ND (P = .0001). Power was generally low (<0.80). Likelihood ratios and Fisher exact tests supported the chi2 analysis.

CONCLUSIONS: In this study, flatfeet did not appear to be a risk factor in subjects with MLBP. However, small sample size, low power, broader age range, low prevalence of flatfeet (>10 mm ND), and lesser back pain severity make these data tentative. Further research is needed.

Relationship Between Positive Clinical Outcomes of Foot Orthotic Treatment and Changes in Rearfoot Kinematics
Gerard V. Zammit, BPod(Hons) * and Craig B. Payne, DipPod, MPH *
* Department of Podiatry, School of Human Biosciences, La Trobe University, Melbourne, Australia.

Corresponding author: Gerard V. Zammit, BPod(Hons), Department of Podiatry, School of Human Biosciences, La Trobe University, Melbourne, Victoria 3086, Australia.


Abstract

Background: Previous two-dimensional kinematic studies that assessed the effect of foot orthoses on rearfoot motion have yielded mixed results regarding whether control of rearfoot motion is related to symptom relief.

Methods: We sought to determine the effect of foot orthoses on rearfoot motion and to correlate these changes with the degree of symptom improvement in 22 individuals with excessive rearfoot pronation (17 women and 5 men; mean ± SD age, 44.3 ± 16.7 years; mean ± SD weight, 74.9 ± 15.9 kg). Two-dimensional motion-analysis software was used to assess frontal plane rearfoot motion with and without foot orthoses. The mean ± SD Foot Posture Index of the left foot was 8.83 ± 3.54 and of the right foot was 9.22 ± 3.64). The pain and function subscales of the Foot Health Status Questionnaire were then used to determine the degree of symptom relief associated with the orthoses at baseline and 4 weeks later.

Results: Orthoses had a small but statistically significant effect on rearfoot motion, although no significant correlations were found between differences in rearfoot motion with and without foot orthoses and the improvements demonstrated in the Foot Health Status Questionnaire subscales of pain and function.

Conclusions: The effect of orthoses on frontal plane rearfoot motion is considered small and probably insufficient to account for the extent of symptom reduction found in this study. Other parameters of orthotic function, such as kinetic and neuromechanical variables, should be further investigated. (J Am Podiatr Med Assoc 97(3): 207–212, 2007)

Effect of extrinsic rearfoot posts on rearfoot position
RL Blake and HJ Ferguson
Center for Sports Medicine, Saint Francis Memorial Hospital, San Francisco.

Twenty runners displaying abnormal subtalar joint pronation were selected for this study, the purpose of which was to investigate the effects of extrinsic rearfoot posted orthoses on frontal plane rearfoot and tibial position. Numerous temporal events were measured and compared for three different conditions: acrylic post, Birko post, and no post. The results suggested that rearfoot posts have a somewhat limited function in foot orthotic therapy and that the choice of posting material is of limited functional value.

Literature. It always shows the way!

Regards
Robert

[robertisaacs]

Sod. I have also found research which supports yours.

Bilateral and unilateral increases in calcaneal eversion affect pelvic alignment in standing position.
Pinto RZ, Souza TR, Trede RG, Kirkwood RN, Figueiredo EM, Fonseca ST.
Man Ther. 2007 Sep 29; [Epub ahead of print]

Quote:
Excessive foot pronation has been associated with the occurrence of low back pain, possibly for generating changes in the lumbopelvic alignment. However, the influence of foot pronation (measured as calcaneal eversion) on pelvic alignment during standing has not been well established. Fourteen young healthy subjects participated in the study. A Motion Analysis System was used to obtain pelvic positions in sagittal and frontal planes and calcaneal position in the frontal plane. Volunteers were filmed in relaxed standing position during three trials, in three conditions: control; unilateral experimental with increased right calcaneal eversion and bilateral experimental with increased bilateral calcaneal eversion. Increased calcaneal eversion was obtained using wedges tilted 10 degrees medially, unilaterally and bilaterally. Repeated measures ANOVAs with Bonferroni corrections were used for statistical analysis. Unilateral and bilateral use of medially tilted wedges produced a significant increase of calcaneal eversion (P0.01), on the right and left sides. Bilateral and unilateral increases of the calcaneal eversion caused average pelvic anteversion of 1.57 degrees (P=0.003) and 1.41 degrees (P=0.021), respectively. Unilaterally increased everted position generated an average pelvic lateral tilt of 1.46 degrees (P<0.001). Excessive calcaneal eversion during standing changes pelvic alignment and should be considered, associated with other relevant factors, when assessing pelvic misalignments.

Effect of feet hyperpronation on pelvic alignment in a standing position.Khamis S, Yizhar Z.
Gait Posture. 2007 Jan;25(1):127-34

Quote:
Hyperpronation may cause malalignment of the lower extremity, frequently leading to structural and functional deficits both in standing and walking. Our aim was to study the effect of induced foot hyperpronation on pelvic and lower limb alignment while standing. Thirty-five healthy subjects were requested to remain in a natural standing position for 20s in four different modes: feet flat on the floor, and on wedges angled at 10 degrees, 15 degrees and 20 degrees, designed to induce hyperpronation. Sequencing was random, repeated three times and captured by eight computerized cameras using the VICON three-dimensional motion analysis system. We found that standing on the wedges at various angles, induced hyperpronation, with 41% to 90% of the changes attributable to the intervention. In addition, a statistically significant increase (paired t-test) in internal shank rotation (p<0.0001), internal hip rotation (p<0.0001) and anterior pelvic tilt (p<0.0001) was identified. A strong correlation was found between segmental alignment in every two consecutive modes at all levels (r=0.612-0.985; p<0.0001). These findings suggest that alignment of the lower extremity up to the pelvic girdle, can be altered, due to forces acting on the foot. Interaction between the foot and pelvis occurs in a kinematic chain reaction manner. Although this study was limited to healthy subjects, clinicians should be aware that when addressing pelvis and lower back dysfunction, foot alignment should be examined as a contributing factor.

Literature. You just can't trust it!

Regards
Robert

[dtt]

Hi Robert

;D ;D ;D

Thank you for looking it all up.

I think that makes us all square at the moment .

I need to show you some positives in practice of my theory about this and see if you can

1 explain them away
Or
2 alter your opinion to a different perspective

Its just I have done CPD with different disciplines and I have altered my thinking on many things since

Roll on January

Cheers

Derek

[rothbart]

Interesting discussion. I would like to add a comment coming from an entirely different paradigm (viewpoint), if I may. That being the Posturologist's paradigm.

Putting insoles underneath the feet have an observerable impact on the entire body. On my research website -
( www.rothbartsfoot.info/PosturalCorrections.html ),
I show numerable changes in posture, pre vs post (proprioceptive) insoles. But how does this occur. If your theoretical model is based on biomechanics, this thread innumerates many of the possible connections between foot mechanics and changes in the position of the pelvis and legs. However, if your theoretical model is based on neurobiomechanics, your explanation of these changes in posture comes from an entirely different point of view. Below, I have capsularized their thinking into just a few sentences:

(1) Mechanical receptors in the bottom of the feet are continuously sending information to the cerebellum regarding the position of the body in space (e.g., its posture).
(2) If these signals are distorted, e.g., abnormal pronation, the cerebellum acts on these distorted signals, resulting in distorted (poor) posture.
(3) Using proprioceptive signals (insoles) underneath the feet, these distorted signals are normalized, before being sent to the cerebellum.
(4) Acting on these normalized signals, the cerebellum directs the posture back towards a more erect position.

Again, this is a very simplistic, brief explanation of the theoretical model proposed by Posturologists. If you like, you can read a more in depth description by accessing the standard text on Posturology written by Marie Pierre Gagey MD (Posturologie, Elsevier Masson).

For over 15 years, I practiced as a biomechanist, however, for the past 20 years my research and clinical work has shifted towards (and now exclusively resides in) neurobiomechanics (Posturology).

Prof B