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Lunge Test not stiff enough

Discussion in 'Biomechanics, Sports and Foot orthoses' started by RobinP, Aug 11, 2011.

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  1. RobinP

    RobinP Well-Known Member


    Members do not see these Ads. Sign Up.
    We use the lunge test to gauge stiffness in the ankle complex. The lower threshold for ankle joint dorsiflexion is 35 degrees, below which the ROM is considered insufficient and may be significant in pathology

    Is there an upper threshold over which we consider the ankle joint complex to be insufficiently stiff? I was describing to a patient tonight the theory behind zones of optimal leg stiffness and I wondered whether the more compliant the leg, the greater likelihood of soft tissue injury theory would apply here

    I don't recall seeing anyuthing about it before but I'm sure someone will find something, making me look like the thing that I am..........lazy

    Thanks to all

    Robin
     
  2. Robin you are getting confused here. Lunge test may not really be the greatest test of stiffness

    Kleg - leg stiffness is intersting stuff but you have to read - leg stiffness

    and yes a more compliant leg there may be a link to more soft tissue injury but it is not a simple.

    Your at a level of understanding now where you don´t get the answers go do some reading and there is lots of it.
     
  3. Griff

    Griff Moderator

    Mike,

    Bit of a brash reply in my opinion, especially as I don't think you have quite understood what Robin is asking. The way I interpreted the original question was as follows (please correct me if I am wrong Robin):

    The weight bearing lunge test is a way of obtaining an indication of ankle joint dorsiflexion stiffness. Previous studies have suggested this may be an indicator of increased lower extremity injury risk. The authors (Gabbe, Pope, Bennell et al) seem to have identified a minimum value for this test (a tibial angle of at least 35 degrees) - failure to achieve this may increase aforementioned injury risk. If there is such as thing as increased ankle joint dorsiflexion stiffness (a tibial angle of less than 35 degrees), then is there also such a thing as decreased ankle joint stiffness?? i.e. Can the ankle joint be TOO compliant and will this carry with it any similar/different risks?

    Is that the gist of what you were asking Robin?
     
  4. Probably a bit - but also maybe it time Robin took the next step as I suggested.

    Anyways not offence was intended just a small kick in the ass.

    Anyway if I got it wrong end of the question - Sorry and I´ll leave you too it.
     
  5. RobinP

    RobinP Well-Known Member

    Ian - you were spot on

    Mike - you are spot on. I am lazy and I do need to do some reading and understanding. A good kick up the bum taken
     
  6. Griff

    Griff Moderator

    Cool - in which case here are my thoughts:

    As far as I am aware there is no 'range' suggested in the literature for the tibial angle values of the Lunge test, there is only a lower threshold (35-38 degrees from memory). Anectodally, I often see angles of 40-45 degrees achieved. To achieve significantly more than this would, to my mind at least, require the individual to have global ligamentous laxity. It seems intuitive that this may correlate with a particular set of potential problems.

    If you need/want all of the lunge test articles let me know and I'll ping them over.
     
  7. RobinP

    RobinP Well-Known Member

    I'm giving this thread a bit of a bump because I have come across a run of patients who I would consider to not have global ligamentous laxity but have lunge tests measuring in excess of 45-50(measured with my phone accelerometer)

    When doing an assessment, ankle lunge test is one of the main tests that I always perform. I measure in barefoot (as I have them barefoot at the time) If the range looks even remotely limited, I make a point of measuring in their shoe/runners .

    I don't measure in the footwear if the test looks ok in barefoot. I seem to recall somewhere, someone had written that the patient had a reduced ankle lunge test when in footwear. Has anyone experienced this? Am I doing something completely wrong by not doing this?

    Anyway, the real reason I posted this is because I was wondering what types of injuries one might envisage coming across in a patient with an excessively high angle when performing an ankle lunge test.

    I was thinking along the lines of any of the soft tissues that resist dorsiflexion moments. Any suggestions?

    Thanks

    Robin
     
  8. efuller

    efuller MVP

    Different tissues resist dorsiflexion moments. So, at "end of range of motion" you have the talar neck hitting the anterior inferior aspect of tibia. There might be some joint capsule getting pinched before the two bones actually touch. In reality, you are very unlikely to get there because the gastroc/soleus will be told to contract before you do get there. Muscle contraction can also limit dorsiflexion. I recall a study that someone posted on the arena where they measured an average of passive dorsiflexion of 10 degrees. Then they measured the average amount of dorsiflexion seen in gait and it was 4 degrees. Entirely plausible considering the gastroc/soleus is capable of easily lifting the whole body. I would doubt that a large range of motion exhibited in a lunge test would correlate with injury to the structures that limit dorsiflexion.

    Eric
     
  9. Eric make and important point re weightbearing and nonweightbearing examination.

    If you think about weight bearing exam Robin and the Gastroc/Sol is ´not´stiff enough what would be the major problems with Gait.

    hint: think of the Gastroc/Sol complex as a spring or Catapult.
     
  10. Ian Drakard

    Ian Drakard Active Member

    If you were looking for a potential injury mechanism, I would have thought that anterior compression injuries might be more likely in this group with jumping activities? Pure speculation though.
     
  11. efuller

    efuller MVP

    I think that folks with a lot of range of motion of the ankle joint in the range of dorsiflexion would be much less likely to have anterior impingement. They have much more time for the gasroc/soleus to limit slow dorsiflexion than someone with a smaller amount of ankle dorsiflexion.

    Eric
     
  12. Orthican

    Orthican Active Member

    (break from reading)...If I'm working along correctly here reduced stiffness in the leg has to be accomodated in gait by the CNS and responds by increasing stiffness in the foot. My thought to go along with that is that would this patient profile ( the ones Robin is discussing)not also be considered to have isolated soleus weakness comparitavely speaking? And as the solues may act agonistically with the ACL might this type of person be susceptable to a potential ACL injury? A less stiff leg sitting on a stiffer foot with a weak soleus playing a sport might get an ACL damaged more often than a healthy subject. At least that is how I'm seeing that with the stiffness idea. Am I out of it? or getting there? Although I'm kind of tired at the moment .....pes anserine bursitis as well?...going to bed..
     
  13. Muscle-tendon interaction and elastic energy usage in human walking

    Ishikawa, Masaki, Paavo V. Komi, Michael J. Grey, Vesa
    Lepola, and Gert-Peter Bruggemann. Muscle-tendon interaction and
    elastic energy usage in human walking. J Appl Physiol 99: 603– 608, 2005.
    First published April 21, 2005;

     
  14. RobinP

    RobinP Well-Known Member

    OK - just to be clear about my thinking

    The reason that I said about "soft tissues that resist dorsiflexion moments" is because I would also find it highly unlikely that the CNS would allow dorsiflexion to the limit of ROM without empolying the gastroc soleus complex. Of course the gastroc/soleus complex is capable of lifting body mass and then some. Does that mean that it cannot be subject to loads outside of its zone of optimal stress when fatigued?

    The reason that I linked to the leg stiffness at first was because my thought process was:

    Decreased ankle joint stiffness would require input from the CNS to increase the overall stiffness of the leg to maintain an optimal shift in COM throughout the gait cycle. For example inceased stiffness at the knee. Possible greater increase in bone stress(whatever that may be)

    HOwever, if the CNS is feeding back that the ankle joint is dorsiflexing too quickly, it might increase knee stiffness but will it not also attempt to increase the stiffness at the ankle joint by increasing the gastroc/soleus load? In the case of a forefoot striking runner,is it not feasible that the increased demand on the gastroc/soleus complex to increase the ankle joint stiffness to maintain the COM position might be enough to cause pathology.


    I'm not examining non weight bearing - lunge test only. Is the point you are making is that I cannot quantify, even subjectively, ankle joint stiffness with a an ankle lunge test as I cannot measure the force required to meet the equilibrium in weight bearing? Not sure I follow what you are saying.


    Not sure Todd. I guess I am saying that any structure which increases overall leg stiffness as a reaction to the decreased ankle joint stiffness, may be susceptible to overuse.

    When we look at decreased 1st ray stiffness, we see pathologies relating to structures attempting reduce the medial column/1st ray dorsiflexion moments. Is it not possible with the ankle?

    Robin
     
  15. efuller

    efuller MVP

    In gait, if you have low ankle stiffness, the CNS will respond by putting the other leg on the ground in front of you to stop ankle joint dorsiflexion. The center of mass has momentum and will continue forward unless something stops it. (Newton's first law). If you have low stiffness, you will probably also have low power output from the ankle. Therefore you wont get any push off of the soon to be trailing leg. Therefore there will have to be more hip pull, to swing the trailing leg forward.

    I don't see why knee stiffness would have to increase to achieve forward progression in gait when there was low ankle stiffness.

    In the forefoot striking runner, at contact, the ankle joint stiffness is a shock absorber. There will usually be some ankle dorsiflexion and this will cause high loads in the Achilles tendon when acting as a shock absorber. Once the foot is loaded, there is not much control of the center of mass by the foot or leg in running. Momentum. The control comes more from foot placement at landing.

    The loads on the Achilles are much more from active muscle contraction than passive stretch/ stiffness.

    Eric
     
  16. Orthican

    Orthican Active Member

    Just thinking out loud here...

    I know it sounded off base but this is why I thought pes anserine earlier. The stabilization, lift to clear the ground and position of the shank in swing are aided to control positional translations during swing not only by the momentum, lig. and capsule connection to the femur, but also by sem m. sem t. bic f. correct? So my jump to that was because I thought that with long term repetitive strain the person would over stress the insertion end and inflame the bursa.

    Would the knee not need to stiffen in order for the CNS to preserve the COM position relatave to the ground by controlling the rate at which the movement of the tibia moved over the foot? An inverted pendulum with a weak axis point will under the same force applied to a normal move slightly faster through the arc of motion would it not? Less resistance to momentum??Or am I out to lunch? My thought again was the cause of the pes anserine because would the hams not also fire eccentrically during the end of a faster tibial arc of motion to resist and control the motion?

    Thanks
     
  17. efuller

    efuller MVP

    I'm having trouble understanding what you mean by preserve the COM position relative to the ground. In what direction are you talking about? What do you mean by preserve? The body is moving relative to the ground. What is a weak axis point?

    A good place to look to understand the energetics of gait is the work of David Winter.

    It sounds like you are talking about forward progression. In that case, Winter showed that in gait the body slowed its progression when the CoM was behind the stance foot and it accelerated forward after body moved anterior to the stance leg. It was a pretty straigthforward exchange of kinetic energy for potential energy and back again. The momentum of the body is decreased as it is lifted up over the stance limb and then falls forward to regain momentum till the other foot contacts. Low stiffness at the ankle is not a problem in this scenario.

    Eric
     
  18. Orthican

    Orthican Active Member

    I was thinking about vertical translation of the COM when I said relative to the ground. When I said preserve I meant maintain. Sorry.

    I will read Winter as well.

    Thankyou.
     
  19. Robin:

    The lunge test measures the range of motion of a number of joints (i.e. ankle, subtalar, midtarsal, and midfoot joints) but does not necessarily measure stiffness of these joints. To measure stiffness, more than one data point is necessary on the load vs deformation curve.

    In many of the responses to your question here, I believe that some people may be discussing running biomechanics and others are talking about walking biomechanics. Since walking and running biomechanics are very different from each other when it comes to ankle joint dorsiflexion kinematics and kinetics, if you, or the person answering your question, doesn't indicate whether they are talking about walking or running, then any discussion basically becomes useless.

    The lunge test, as it is typically done with the knee flexed and ankle dorsiflexed, probably has little bearing on injuries or the production of normal gait during walking since it is done with the ankle dorsiflexed and the knee flexed. During walking, maximum ankle dorsiflexion occurs when the knee is nearly fully extended so the lunge test probably doesn't apply for walking, but applies more for running mechanics where knee and ankle joint dorsiflexion occurs at the same time.
     
  20. Griff

    Griff Moderator

    Does anyone have access to Manual Therapy journal? I can't seem to access it via my Athens account. From the current issue:

    Matthew C. Hoch, Patrick O. McKeon
    Normative range of weight-bearing lunge test performance asymmetry in healthy adults
    Manual Therapy, Volume 16, Issue 5, (October 2011) p516-519
     
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