Welcome to the Podiatry Arena forums

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, upload content, view attachments, receive a weekly email update of new discussions, access other special features. Registered users do not get displayed the advertisements in posted messages. Registration is fast, simple and absolutely free so please, join our global Podiatry community today!

  1. Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
    Dismiss Notice
Dismiss Notice
Have you considered the Clinical Biomechanics Boot Camp Online, for taking it to the next level? See here for more.
Dismiss Notice
Have you liked us on Facebook to get our updates? Please do. Click here for our Facebook page.
Dismiss Notice
Do you get the weekly newsletter that Podiatry Arena sends out to update everybody? If not, click here to organise this.

Understand the concept of FnHL but can't get the clinical test right?

Discussion in 'Biomechanics, Sports and Foot orthoses' started by AdamB, May 1, 2013.

  1. AdamB

    AdamB Active Member


    Members do not see these Ads. Sign Up.
    Hello,

    After much reading I think I have a basic understanding of the concept and biomechanics of FnHL and the role of reduced first ray dorsiflexion stiffness.... however I just can't seem to translate that into an effective clinical test.

    I am pretty confident that I personally have FnHL bilaterally and already have the very early signs degenerative changes in the joints.

    Non-weightbearing I have a good 60*+ of dorsiflexion. Using one clinical method of assessment, I stand in relaxed stance and try to lift / dorsiflex my hallux it is near on impossible - suggesting a FnHL. But when I take one of my feet and place it in a neutral position and load up the 1st met head forcefully with my thumb (dorsiflex the first ray) and then load the plantar aspect of the hallux to dorsiflex it, the hallux dorsiflexes fairly easily and the met head plantarflexes and the windlass engages properly.

    Why the negative result using one clinical method and the positive result using another? What is the best and most reliable test for FnHL? And should we be testing everybody for FnHL?

    Thanks
     
  2. Samuel Ong

    Samuel Ong Member

    :welcome:

    I use the Jacks test (the first test you described), and have found it to be pretty reliable. You can measure both the force needed to activate the windlass & timing of windlass activation.

    Force- How hard you need to dorsiflex the hallux before the windlass is activated. For those patients you will need prescribe something to lower the force needed to activate the windlass, eg. medial skive, rearfoot varus post, forefoot valgus post, reverse mortons extension.

    Timing- In some patients the windlass activation is delayed. The hallux has to be dorsiflexed to a certain degree before the windlass "kicks in", ie. inversion of calcaneus, forming of the MLA. For those patients you can prescribe something to "hasten" the windlass activation eg. cluffy wedge, heel lift.

    I think the reason one test is positive and the other is negative is because one is perform weigthbearing and the other non-weightbearing. The force exerted by your thumb during the non-bearing test is disproportionate to that of the ground reaction force exerted when performing the Jacks test.

    Hope this helps ;)
     
  3. Adam:

    Welcome to Podiatry Arena.:welcome:

    Your question, by the way, is an excellent one.

    The test you are describing has at least a couple of different names: Hubscher Maneuver and Jack's Test.

    Basically, the Hubscher Maneuver is performed with the feet in relaxed bipedal stance with the examiner dorsiflexing the hallux and then observing the results. In a foot with normal 1st metatarsophalangeal joint (MPJ) dorsiflexion (about 65- 70 degrees), normal medial longitudinal arch (MLA) height, an intact plantar fascia and a normal subtalar joint (STJ) axis location, the Hubscher Maneuver will produce hallux dorsiflexion, first ray plantarflexion, STJ supination and external tibial rotation as originally described by John Hicks nearly six decades ago (Hicks JH: The mechanics of the foot. II. The plantar aponeurosis and the arch. J Anatomy. 88:24-31, 1954).

    If however, hallux dorsiflexion with the feet in relaxed bipedal stance produces limited to no hallux dorsiflexion, and that foot also has its normal range of hallux dorsiflexion (i.e. 65-70 degrees) in the non-weightbearing examination, then we would consider that foot to have a functional hallux limitus (FnHL), first described by Patrick Laird, DPM in 1972 (Laird PO: Functional hallux limitus. The Illinois Podiatrist. 9:4, 1972).

    Holding the foot supinated while in relaxed bipedal stance with the first metatarsal head being non-weightbearing will, of course, produce increased hallux dorsiflexion since the plantar fascial band (i.e. medial slip of central component of plantar aponeurosis) will be unloaded while the foot is standing with the first metatarsal head non-weightbearing. This modified test you are describing here, with the first metatarsal head non-weightbearing, however, would not be considered to be either a Jack's Test or a Hubscher Maneuver since both of these tests are always done while the foot is in relaxed bipedal stance position.

    In addition, it would be very difficult to get a valid Hubscher Maneuver trying to perform the test on your own body since the individual must be standing upright in order to get a valid test. Leaning the body forward, with the center of mass (CoM) more anterior to the ankle joint axis will increase the force required to dorsiflex the hallux while leaning the body backward, with the CoM posterior to the ankle joint axis will decrease the force required to dorsiflex the hallux.

    Hope this helps.:drinks
     
  4. AdamB

    AdamB Active Member

    Hi Samuel, thanks for the explanation. As far as I was aware, the non-weightbearing test by exerting a force to the 1st met head and loading / dorsiflexing the first metatarsal and then attempting to dorsiflex the hallux was a technique used and described widely? I could be wrong, I will try the weightbearing test again on my next few pts and see how it goes.

    Cheers
     
  5. AdamB

    AdamB Active Member

    Hi Kevin, thanks for the welcome and explanations. Yes, I thought that trying to do this Hubscher maneuver on myself might be fraught with danger :D

    Exactly how much force is enough when attempting to dorsiflex the hallux while performing this maneuver? The link you provided describes the patient sitting down - Is the patient fully weightbearing - ie sitting down or standing up? What fingers / thumb should I be using and from which angle?? What if you have small delicate hands (I don't) and the patient is big heavy man with huge feet?

    Sorry for all the questions, and thanks again for the link.
     
  6. The patient needs to be standing up, not sitting down, to properly perform the Hubscher maneuver. I generally use my index and middle fingers to lift the hallux from distally on the hallux. Generally, less than 20 pounds of force is necessary to dorsiflex the hallux at the distal phalanx level for patients without a functional hallux limitus, even in larger individuals.

    I have had small children require more manual force to dorsiflex the hallux than the manual force required to dorsiflex the hallux in large men. In addition, feet with flatter medial longitudinal arch height and more medial subtalar joint axis deviation will require more manual hallux dorsiflexion force to dorsiflex the hallux than in feet with normal to high medial longitudinal arch height and normal to lateral subtalar joint axis location.

    Here is another thread you may want to look at:

    Is Jack's Test Valid?
     
  7. Another important concept is not just the 1st but other digits can and will change dorsiflexion stiffness on weightbearing.
     
  8. AdamB

    AdamB Active Member

    Thanks Kevin, much appreciated. :drinks
     
Loading...

Share This Page