Welcome to the Podiatry Arena forums, for communication between foot health professionals about podiatry and related topics.
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 (PM), upload content, view attachments, receive a weekly email update of new discussions, earn CPD points and access many other special features. Registered users do not get displayed the advertisments in posted messages. Registration is fast, simple and absolutely free so please, join our global Podiatry community today!
If you have any problems with the registration process or your account login, please contact contact us.
Inter-assessor reliability of practice based biomechanical assessment of the foot and ankle
Hannah L Jarvis, Christopher J Nester, Richard K Jones, Anita E Williams and Peter D Bowden Journal of Foot and Ankle Research 2012, 5:14
Quote:
Background
There is no consensus on which protocols should be used to assess foot and lower limb biomechanics in clinical practice. The reliability of many assessments has been questioned by previous research. The aim of this investigation was to (i) identify (through consensus) what biomechanical examinations are used in clinical practice and (ii) evaluate the inter-assessor reliability of some of these examinations.
Methods
Part1: Using a modified Delphi technique 12 podiatrists derived consensus on the biomechanical examinations used in clinical practice. Part 2: Eleven podiatrists assessed 6 participants using a subset of the assessment protocol derived in Part 1. Examinations were compared between assessors.
Results
Clinicians choose to estimate rather than quantitatively measure foot position and motion. Poor inter-assessor reliability was recorded for all examinations. Intra-class correlation coefficient values (ICC) for relaxed calcaneal stance position were less than 0.23 and were less than 0.14 for neutral calcaneal stance position. For the examination of ankle joint dorsiflexion, ICC values suggest moderate reliability (less than 0.61). The results of a random effects ANOVA highlight that participant (up to 5.7degrees), assessor (up to 5.8degrees) and random (up to 5.7degrees) error all contribute to the total error (up to 9.5degrees for relaxed calcaneal stance position, up to 10.7degrees for the examination of ankle joint dorsiflexion). Kappa Fleiss values for categorisation of first ray position and mobility were less than 0.05 and for limb length assessment less than 0.02, indicating slight agreement.
Conclusion
Static biomechanical assessment of the foot, leg and lower limb is an important protocol in clinical practice, but the key examinations used to make inferences about dynamic foot function and to determine orthotic prescription are unreliable.
Re: Reliability of clinical biomechanical assessments
Nothing new here then.
Lets play a little game.
Assume that each subject was symptomatic and that following each examination each podiatrist individually prescribed ortheses.
Of all the different orthoses prescribed, based on a broad range of different results, what percentage do you think (gut feeling)would imrove or resolve the symptoms, based on your experience?
I'll suggest 70%.
What do you think?
Actually it's not worth the effort.
We already know that if you forget the examination and just let the patient select a pair of comfortable over the counter 'orthoses' that the 'cure' rate will be very high.
Maybe it's just not an exact science, ie a few degrees here or their doesn't make much difference?
I'm in the Rob Kidd school of biomechanics where the guiding principle is "Do something different", ie in an 'expert' way.
I hope I am not misrepresenting Robb in the above statement but if I am I am sure he will let me know.
Bill
The Following 2 Users Say Thank You to wdd For This Useful Post:
Re: Reliability of clinical biomechanical assessments
We did some research on the same subject from a decade ago. Chris Nester and I will be having a chat today in Manchester at the hotel and I will see if Chris has anything more of interest to say about this research.
Quote:
J Am Podiatr Med Assoc. 2002 Jun;92(6):317-26.
Reliability and accuracy of biomechanical measurements of the lower extremities.
Van Gheluwe B, Kirby KA, Roosen P, Phillips RD.
Source
Vrije Universiteit Brussel, Laboratory of Biomechanics, Belguim.
Abstract
The reliability of biomechanical measurements of the lower extremities, as they are commonly used in podiatric practice, was quantified by means of intraclass correlation coefficients (ICCs). This was done not only to evaluate interrater and intrarater reliability but also to provide an estimate for the accuracy of the measurements. The measurement protocol involved 30 asymptomatic subjects and five raters of varying experience. Each subject was measured twice by the same rater, with the retest immediately following the test. The study demonstrated that the interrater ICCs were quite low (< or =0.51), except for the measurements of relaxed calcaneal stance position and forefoot varus (both 0.61 and 0.62 for left and right, respectively). However, the intrarater ICCs were relatively high (>0.8) for most raters and measurement variables. Measurement accuracy was moderate between raters.
__________________
Sincerely,
Kevin
**************************************************
Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
Re: Reliability of clinical biomechanical assessments
Do many people still use relaxed calc stance to devise an orthotic prescription? I thought it was all about using the 'force' these days! Tissue stress theory and all that. Jacks test and Supination resistance test and transverse plane axis location of the subtler joint.
Re: Reliability of clinical biomechanical assessments
Quote:
Originally Posted by wdd
Maybe it's just not an exact science, ie a few degrees here or their doesn't make much difference?
We need to stop thinking about foot orthoses in terms of posting angles. It is the entire geometry of the device which is important; that and it's load/deformation and frictional characteristics. The belief that there should only be one solution to the patients problem based on achieving the exact "correct" posting angle of a device is lunacy.
That said, it is possible that "a few degrees here or there" could hypothetically be the difference 'twixt success and failure in foot orthoses therapy:
1) If we have a zone of optimal stress (ZOOS) for our target tissue, then the orthotic device might be assumed to be successful if we place the tissue which was previously functioning outside of its ZOOS somewhere within its ZOOS via our foot orthoses, allowing the tissue to heal.
2) When we do this we don't know exactly where the tissue lies within it's ZOOS due to our orthotic intervention; it could be smack bang in the middle or right on the border of it's upper or lower limit, yet all would result in a positive outcome. All we know is that our orthotic has placed the tissue somewhere within it's ZOOS (or not, if we don't get a positive outcome)
3) If the orthosis places the tissue somewhere near the middle of its ZOOS, we can probably change the orthotic posting by "a few degrees here or there" and the patient will still get better since the orthotic variations all still place the tissue somewhere within its ZOOS.
4) However, if our orthoses puts the tissue only just within it's ZOOS, then small changes in the prescription might just tip the tissue outside of its ZOOS and result in therapeutic failure.
Re: Reliability of clinical biomechanical assessments
Quote:
Originally Posted by Robertisaacs
Much wisdom here.
We still tend to think in terms of the right thing, as opposed to one of the right things.
That said, within the solution set, some will be more optimal than others. Finding such optimal solutions is "the real trick"- right, kid? This is where our understanding of the kinetic interaction between foot orthoses variables and the foot come into play. A good starting point for the student of foot orthoses therapy should be to list all of the different prescription variables they can think of, consider how manipulating these will influence the 3 primary foot orthoses variables (geometry at foot-orthosis interface, load/ deformation at foot-orthosis interface, frictional characteristics at foot-orthosis interface) then consider the kinetic effects these might have on the distribution of reaction force magnitudes across the foot-orthosis interface and viz. centre of pressure position (I know it's not a full vector analysis, but centre of pressure is pretty easy for everyone to understand, and should provide a reasonable starting point).
Re: Reliability of clinical biomechanical assessments
Quote:
Originally Posted by Simon Spooner
1) If we have a zone of optimal stress (ZOOS) for our target tissue, then the orthotic device might be assumed to be successful if we place the tissue which was previously functioning outside of its ZOOS somewhere within its ZOOS via our foot orthoses, allowing the tissue to heal.
2) When we do this we don't know exactly where the tissue lies within it's ZOOS due to our orthotic intervention; it could be smack bang in the middle or right on the border of it's upper or lower limit, yet all would result in a positive outcome. All we know is that our orthotic has placed the tissue somewhere within it's ZOOS (or not, if we don't get a positive outcome)
3) If the orthosis places the tissue somewhere near the middle of its ZOOS, we can probably change the orthotic posting by "a few degrees here or there" and the patient will still get better since the orthotic variations all still place the tissue somewhere within its ZOOS.
4) However, if our orthoses puts the tissue only just within it's ZOOS, then small changes in the prescription might just tip the tissue outside of its ZOOS and result in therapeutic failure.
If a tissue is injured will the range of its ZOOS be narrower and its upper and lower limits reduced? Could it be that in some cases the range might be so narrow and the upper an lower limits so low that, until there is some healing the ZOOS could be zero, ie total rest is required?
As the tissue heals the range and the upper and lower limit of ZOOS increases.
With continued training the the upper and lower limit if ZOOS will continue to increase towards some upper limit.
What I am saying is that there is no single ZOOS for a tissue, it is a dynamic range and depends upon the 'health ' of the tissue. Also the ZOOS for one part of the same tissue might be very different from the ZOOS of another part of the same tissue.
How would that relate to 1 to 4 above?
At this time, is the only way of knowing you are outside the ZOOS 'OUCH'!
Is it currently possible to put a number to a ZOOS? If not can you envisage it becoming possible? What would need to change to make it possible?
best wishes,
Bill
The Following User Says Thank You to wdd For This Useful Post:
Re: Reliability of clinical biomechanical assessments
Quote:
Originally Posted by wdd
If a tissue is injured will the range of its ZOOS be narrower and its upper and lower limits reduced? Could it be that in some cases the range might be so narrow and the upper an lower limits so low that, until there is some healing the ZOOS could be zero, ie total rest is required?
As the tissue heals the range and the upper and lower limit of ZOOS increases.
With continued training the the upper and lower limit if ZOOS will continue to increase towards some upper limit.
What I am saying is that there is no single ZOOS for a tissue, it is a dynamic range and depends upon the 'health ' of the tissue. Also the ZOOS for one part of the same tissue might be very different from the ZOOS of another part of the same tissue.
How would that relate to 1 to 4 above?
At this time, is the only way of knowing you are outside the ZOOS 'OUCH'!
Is it currently possible to put a number to a ZOOS? If not can you envisage it becoming possible? What would need to change to make it possible?
best wishes,
Bill
Bill, those are the best questions I have been asked here in a long time.
I terms of range, I suspect your contention is correct in that the range will be reduced in a dysfunctional situation. Perhaps, this is one of the reasons the injury occurs in the first place. Clearly, if we have an injury of sufficient magnitude the ZOOS could be zero, in that the tissue cannot develop any strain within it what-so-ever in relation to the stress applied- think Achilles tendon in complete rupture. I used to give a lecture on how the load/deformation of the tissue change with time after injury- I'll see if I can find the powerpoint.
Certainly healing and training should influence the breadth of the ZOOS.
ZOOS is indeed dynamic and changes dynamically.
Regarding "Ouch" as an indicator- its probably the most easily accessible indicator, but obviously if we are seeing things like atrophy of muscle, this may be an early indicator.
You could put SOME numbers on ZOOS, but probably not get away with it in-vivo or ethically. If we chopped off your leg right now and put the various tissues straight into a materials testing machine we could get reasonable values for the upper limits of the ZOOS, for you, today. The only way you could do it in-vivo, is to use materials testing data obtained as above and then employ CT / MRI data to get an anatomical make up in terms of size etc. then use finite element modelling (FEM) to derive an approximation- it would only be an approximation though, but reasonable for the upper ZOOS. Deriving lower limits of ZOOS should be more tricky and we probably need to look to the research NASA has performed in reduced gravitational fields and animal studies of immobilisation. Again, we could use FEM to model this.
Re: Reliability of clinical biomechanical assessments
I am currently dragged out of retirement and back at work, and I even get quoted in Pod arena! Bill, let us be quite clear. What I have said on several occasions, is that skin line measurements are a nonsense for two reasons. First, as quoted above, their reliability is rubbish. Second, and perhaps more importantly, they tend to replace cognitive processes - people stop thinking. I have always urged students to think ctitically about the issues in front of them. I make the assumption that the world has moved on from the nonsense of 1/3 - 2/3 ratio calculations, but this was a classic example of "cognition replacement theory" - never mind the other arguments.
__________________
Honorary Research Associate, Institute for Human Evolution, University of Witwatersrand
Adjunct Associate Professor (Human and Comparative Anatomy), University of Western Sydney
Fellow of The Centre For Human Biology, The University of Western Australia
"Please God, deliver me whole from Creationists......."
The Following 4 Users Say Thank You to Rob Kidd For This Useful Post:
Re: Reliability of clinical biomechanical assessments
Quote:
Originally Posted by Simon Spooner
We need to stop thinking about foot orthoses in terms of posting angles. It is the entire geometry of the device which is important; that and it's load/deformation and frictional characteristics. The belief that there should only be one solution to the patients problem based on achieving the exact "correct" posting angle of a device is lunacy.
That said, it is possible that "a few degrees here or there" could hypothetically be the difference 'twixt success and failure in foot orthoses therapy:
1) If we have a zone of optimal stress (ZOOS) for our target tissue, then the orthotic device might be assumed to be successful if we place the tissue which was previously functioning outside of its ZOOS somewhere within its ZOOS via our foot orthoses, allowing the tissue to heal.
2) When we do this we don't know exactly where the tissue lies within it's ZOOS due to our orthotic intervention; it could be smack bang in the middle or right on the border of it's upper or lower limit, yet all would result in a positive outcome. All we know is that our orthotic has placed the tissue somewhere within it's ZOOS (or not, if we don't get a positive outcome)
3) If the orthosis places the tissue somewhere near the middle of its ZOOS, we can probably change the orthotic posting by "a few degrees here or there" and the patient will still get better since the orthotic variations all still place the tissue somewhere within its ZOOS.
4) However, if our orthoses puts the tissue only just within it's ZOOS, then small changes in the prescription might just tip the tissue outside of its ZOOS and result in therapeutic failure.
Quote:
Originally Posted by wdd
If a tissue is injured will the range of its ZOOS be narrower and its upper and lower limits reduced? Could it be that in some cases the range might be so narrow and the upper an lower limits so low that, until there is some healing the ZOOS could be zero, ie total rest is required?
As the tissue heals the range and the upper and lower limit of ZOOS increases.
With continued training the the upper and lower limit if ZOOS will continue to increase towards some upper limit.
What I am saying is that there is no single ZOOS for a tissue, it is a dynamic range and depends upon the 'health ' of the tissue. Also the ZOOS for one part of the same tissue might be very different from the ZOOS of another part of the same tissue.
How would that relate to 1 to 4 above?
At this time, is the only way of knowing you are outside the ZOOS 'OUCH'!
Is it currently possible to put a number to a ZOOS? If not can you envisage it becoming possible? What would need to change to make it possible?
best wishes,
Bill
Two exceptionally well articulated posts on the subject matter (as well as Simon's follow-up response to the above).
Re: Reliability of clinical biomechanical assessments
Quote:
Originally Posted by Rob Kidd
I am currently dragged out of retirement and back at work, and I even get quoted in Pod arena! Bill, let us be quite clear. What I have said on several occasions, is that skin line measurements are a nonsense for two reasons. First, as quoted above, their reliability is rubbish. Second, and perhaps more importantly, they tend to replace cognitive processes - people stop thinking. I have always urged students to think ctitically about the issues in front of them. I make the assumption that the world has moved on from the nonsense of 1/3 - 2/3 ratio calculations, but this was a classic example of "cognition replacement theory" - never mind the other arguments.
Dear Rob,
Nice to have you back (out of retirement).
If I remember correctly, you published a paper of regarding forefoot varum (Forefoot Varus: real or false, fact or fantasy, 1997).
Please correct me if I am mistaken: from an embryological point of view, forefoot supinatus is linked to calcaneal supinatus. That is unwinding of the calcaneus, takes with it, the embryological lateral column of the foot. Unwinding of the talus, takes with it, the embryological medial column of the foot.
That being said, in the sequential ontogenetic development of the foot (distal to proximal), forefoot supinatus (forefoot varum) can only exist if the calcaneus is in supinatus.
That is, if the ontogenetic development of the foot stops when the heel bone is in supinatus, the entire forefoot may be in supinatus.
However, if the ontogenetic development of the foot stops when the calcaneus has totally unwound but the talus is still in supinatus, then only the embryological medial column of the foot remains in supinatus (e.g., navicular, medial cuneiform, first metatarsal, proximal phalange and hallux).
That being said, and if correct, than the notion of forefoot varum, from an embryological point of view, is highly improbable, if not impossible.
In 2002 I suggested that a abnormal embryological foot structure can exist where only the medial column of the foot remains in supinatus. I termed this foot structure Primus Metatarsus Supinatus. Also, I suggested that another more severe structural embryological deformation can occur if the ontogenetic development of the foot stops when the heel bone is still marginally in supinatus. I termed this foot structure the PreClinical Clubfoot Deformity. (A more severe calcaneal supinatus can be referred to as a Clubfoot Deformity)
You can read more about these foot structures on my research website at : www.RothbartsFoot.es
Re: Reliability of clinical biomechanical assessments
Quote:
Originally Posted by Brian A. Rothbart
Dear Rob,
Nice to have you back (out of retirement).
Answer is interleaved, in order to address each point.
If I remember correctly, you published a paper of regarding forefoot varum (Forefoot Varus: real or false, fact or fantasy, 1997).
I did - about 1997-8. As with most if not all my podiatric publications (as against my anthropological work), it was met with either silence or aggression. The points I was making, if memory is correct, were to look and question the basis for the aetiology and the diagnosis. Both are a nonsense. To be quite clear, there is no doubt that the head of the talus undergoes a valgus torsion - the numbers are not relevant in this context - but it has zero to do with forefoot-hindfoot relationship. It is actually to do with decreasing the ROM at the MT joint (let's not get involved in the MT restraining mechanism at this stage) It is a classic piece of peramorphic heterachrony; to understand this one needs to look at the same change in African apes. As I have said several times before, the seminal work on this was by Professor Pete Lisowski in 1967 - ignored by podiatrists apart from me and my students.
Please correct me if I am mistaken: from an embryological point of view, forefoot supinatus is linked to calcaneal supinatus. That is unwinding of the calcaneus, takes with it, the embryological lateral column of the foot. Unwinding of the talus, takes with it, the embryological medial column of the foot.
I am not convinced about your nomenclature. I have no know knowledge of embryological forefoot-hindfoot relationship. What I do know is that the embryological talus and calcanus start in a side-by side situation, the calcaneus being lateral. Then, suddenly, the calcaneus becomes plantar and inverted; and then gradually, but rarely completely, the calcaneus everts back to a "vertical" situation. That is why reafoot varus (or whatever jargon is used these days) is so common it is a variant on normal in the majority of cases.
I am not sure that is relevant here, but it is worth mentioning that those changes we have noted in the fossil record are aligned to body planes: latero-medial; disto-proximal and (not so well defined) dorso-plantar. It is incredibly important to remember that latero-medial is embryologically caudo-cranial.
And then one remembers that the genes or other growth factors that causes changes are also aligned to body planes: HOX gens to disto proximal; Sonic Hedgehog proteins for caudo-cranial; Wnt systems for dorso plantar. Thus we are finding in the fossil record, "morphometric ghosts" of our genetics.
That being said, in the sequential ontogenetic development of the foot (distal to proximal), forefoot supinatus (forefoot varum) can only exist if the calcaneus is in supinatus.
I do not have an opinion on this.
That is, if the ontogenetic development of the foot stops when the heel bone is in supinatus, the entire forefoot may be in supinatus.
Again, I have problems with the nomenclature.
However, if the ontogenetic development of the foot stops when the calcaneus has totally unwound but the talus is still in supinatus, then only the embryological medial column of the foot remains in supinatus (e.g., navicular, medial cuneiform, first metatarsal, proximal phalange and hallux).
Ontogenetic development does not stop until adulthood. Many important pedal changes are still happening at perhaps 16 yo. You give no reference for you thoughts, and it is an area about which I am clearly in need of education. Thus I would be glad if you woudl forward this to me, and indeed all the others out there.
That being said, and if correct, than the notion of forefoot varum, from an embryological point of view, is highly improbable, if not impossible.
I am on record of saying that forefoot varus, apart from as a rare anatomical entity, is fictitous, it simply does not exist. IMHO, it is an artifact of the neutral casting process, which to this date, no one, apart from me, has had the balls to queston.
In 2002 I suggested that a abnormal embryological foot structure can exist where only the medial column of the foot remains in supinatus. I termed this foot structure Primus Metatarsus Supinatus. Also, I suggested that another more severe structural embryological deformation can occur if the ontogenetic development of the foot stops when the heel bone is still marginally in supinatus. I termed this foot structure the PreClinical Clubfoot Deformity. (A more severe calcaneal supinatus can be referred to as a Clubfoot Deformity)
Certainly there is a critical lateral column-medial column issue, as clearly demonstrated by the OH8 study 20 years ago. To my knowledge no study in a referreed journal has addressed embryological relationships of the sort to which you refer.
You can read more about these foot structures on my research website at : www.RothbartsFoot.es
with regards,
Brian R
I am not sure how much help I have been; I suspect we are not coming from the same place, so to speak.
Kind regards
Rob
__________________
Honorary Research Associate, Institute for Human Evolution, University of Witwatersrand
Adjunct Associate Professor (Human and Comparative Anatomy), University of Western Sydney
Fellow of The Centre For Human Biology, The University of Western Australia
"Please God, deliver me whole from Creationists......."
Re: Reliability of clinical biomechanical assessments
Dear Rob,
We may not be coming from the same place, but I believe we may well be headed to the same place (different spokes on the wheel all leading to the same hub, so to speak).
For the past thirty years or so, I have been convinced that identifying the cause of abnormal pronation lies in isolating and delineating the variances in the ontogenetic development of the embryo which can result in abnormal congenital foot structures. I believe it is these abnormal congenital foot structures that force the foot to abnormally pronation.
For the past 30 years or so I have been researching a plausible link between abnormal foot pronation and the development of chronic musculoskeletal pain. I have developed a theory that suggests the way the foot moves produces patterns of stimulation from the embedded plantar mechanical receptors in the skin. These patterns of stimulation provide information to the cerebellum, moment to moment, where the body is in space. From this information, the cerebellum makes adjustments in the posture to maintain balance. If these patterns of stimulation are skewed (e.g., the foot is abnormally pronating), the cerebellum acts on these distorted signals resulting in a distorted posture. In time this distorted posture results in chronic muscle and joint pain.
I mention all this, because your publications have provided me with much 'food for thought' (no flattery intended, just factual).
I believe the degree talar torsion present at birth has a great deal to do with the structure and functioning of the foot. I say this based on my surgical experience, my research and the research done by an orthopod by the name of Daniels (1966 Jour Bone Joint Surgery, Am). Daniels found a direct correlation between the varum alignment of the talar neck and the horizontal plane position of the forefoot (in vitro study using 12 cadaver feet).
True, this rearfoot to forefoot relationship he described, is transverse plane relationship. What I am suggesting is that the valgus torsion of the talar head determines, in large part, the frontal and sagittal plane position of the entire embryological medial column of the foot. I first observed this talar head to medial column relationship while I was a performing triple arthrodesis (some 30 years ago). I observed that the position I fused the subtalar joint, impacted the sagittal plane position of the forefoot. That is, the sagittal plane position of the talar neck and head, in large part, determined the sagittal plane position of the first metatarsal and hallux.
My research over the past many years has extended my vision where now I believe it is the torsion within the head of the talus that determines the sagittal and frontal plane position of the embryological medial column (See: http://rothbartsfoot.es/TalarHeadUnwinding.html).
An interesting study was done by Cummings et. al. at Georgia University (Physiotherapy Research International, 1997). He set out to see if he could reliably measure the foot that resulted from this theorized talar torsion (a foot structure I termed Primus Metatarsus Supinatus and described as an abnormal embryological foot structure - Bodywork and Movement Therapies, 2002 - a peer reviewed journal). His study and conclusion was as follows:
Study: Thirty-two volunteers, 18 females (mean age 38.9 ± 15.3 yr) and 18 males (mean age 44.8 ± 20.6 yr) participated in the study. Four examiners performed repeated forefoot measures on both feet using the weight bearing technique during two test sessions separated by a week. Intrarater and interrater reliability (ICC (3,1)) ranged from 0.90 to 0.95 and 0.87 to 0.94, respectively. Day-to-day reliability (ICC (1,1)) ranged from 0.84 to 0.88 for all measures.
Basically Cummings found that this foot structure could be easily and accurately measured with high Intrarater and Interrater reliability.
The ontogenetic development of the talar head may well continue to develop until adulthood. To date, I have read of no studies to confirm this, quantify this, or reject this premise.
I have read, with a smile on my face, your loud and clear statement that both forefoot varum and forefoot supinatus are fictitous, simply does not exist. However, in one point you are wrong. There is another person who has the balls to say this, me!
Reliability of clinical biomechanical assessments
Bill, those are the best questions I have been asked here in a long time.
Linear Mode
