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.

How do I off load the first met head but still allow windlass to work?

Discussion in 'Biomechanics, Sports and Foot orthoses' started by TEW, May 19, 2006.

  1. TEW

    TEW Member


    Members do not see these Ads. Sign Up.
    A patient of mine is a 29 year lady who has high arches and clawed toes bilaterally. Consequently her met heads are very prominent. 10 years ago she fractured her seamoids on one foot (obviously through constant over loading) and had them surgically removed. She has had orthoses ever since, but the pain at the first submet has never gone completely. I made her a new pair of orthoses 12 months ago. They are made from TL2100 with a met dome and 3mm full length spenco cover. I am confident they are controlling her rearfoot eversion. But she still gets pain at her first submet heads bilaterally, particularly when standing for long periods. Playing basketball and following basketball matches she is also in some dsicomfort. The submets are painful to palpate post basketball but not after prolonged rest (first thing in morning).

    I believe there is still too much force going through the first MPJ during her gait. Her forefoot to rearfoot alignment is perpendicular so a forefoot valgus wedge is not indicated.

    I know I need to off load the amount of weight passing through the first MPJ to help relieve her discomfort. But I don't want to prevent the first ray from plantar flexing and hence interrupting windlass.

    She sternly informed me she doesn't want to have any more surgery on her feet. Does anyone have some suggestions on how I should go about modifying her devices to help relieve some of her discomfort?
     
  2. Donna

    Donna Active Member

    What about a reverse Morton's extension? :confused:
     
  3. Craig Payne

    Craig Payne Moderator

    Articles:
    8
    Yes. Reverse mortons extension; a 2-5 bar; a forefoot valgus post.
    I would still use one.
     
  4. TEW

    TEW Member

    Thanks for that.
    We use a lab for our orthoses so I will order a 2-5 bar addition to the devices using grey EVA. I agree that this is probably the best way to improve the patients comfort. Is there any other ways of including a 2-5 bar? Do you think that initially ordering a reverse mortons extension in the shell of the device would have been more effective than adding the EVA addition?
     
  5. Donna

    Donna Active Member

    Hi TEW

    The reverse Morton's extensions that I have used have been made from 2mm low density EVA and added separate to the shell. The lab (that I used in a previous job) would add the 2mm EVA under a 3/4 or full length top cover similar to a PMP or soft tissue supplement pad. In the lab that I currently use, they add the reverse Morton's extension in 3mm PPT.

    I wonder if using a reverse Morton's extension "intrinsic" to the shell would be more durable? :confused:

    Regards

    Donna
     
  6. nicpod1

    nicpod1 Active Member

    TEW,

    As well as the reverse Mortons extension, I've had good results with incorporating ways to address 'equinous features' including calf stretching and Physios should be able to mobilise the STJ, MTJ, ankle, plantar fascia and strengthen the flexors to counteract the extensors.

    Obviously, in basketball, she is going to be one her toes more often, so perhaps the orthoses aren't working in the way that you would hope them to?

    Just a thought!
     
  7. David Smith

    David Smith Well-Known Member

    TEW

    Is it possible that this is more a capsular injury resulting from excessive dorsiflexion moments acting about the hallux MPJ. In this case the treatment may be to increase plantarflexion moments, which might be achieved by fitting a stiffener to the orthosis or the shoe sole.

    Cheers Dave Smith
     
  8. TEW

    TEW Member

    You're right in regards to addressing "equinous features", I have prescribed both calf and hamstring streching regimes. Not sure on the patients compliance though - common theme! I reckon night splints that hold the foot in DF position would be best option. Have you used these before? I know of one pod who swears by them as a component of treatment for plantar fasciitis.

    I see how manipulations may help, patient willing of course.

    With the addition of the extrinsic forefoot post the orthoses will still playing a role while client is "on her toes" while playing basketball. Will let you know how It goes.
     
  9. TEW

    TEW Member

    I see your reasoning dave. I take it you mean increase the plantar flexion moments about the hallux mpj.

    What do you mean "stiffener" and where do you suggest it should be added on the orthotic or in fact shoe? Is the idea to reduce DF moments not to actually increase PF moments?
     
  10. efuller

    efuller MVP

    I sometimes make the mistake of not carefully defining the momenets as was done above. It can get confusing if you don't identify the source of the momnets. When the heel lifts, in gait, there is a dorsiflexion moment from ground reactive force acting on the hallux at the 1st mpj. If the resistance to dorsiflexion is low then the MPJ will dorsiflex. If the resistance to dorsiflexion is high, from a force couple of tension in the plantar structures and compression at the joint surface, then the toe will not dorsiflex. (Hallux limitus or functional hallux limitus.) The resistance to dorsiflexion is from a high internal plantar flexion moment on the hallux.

    When the foot is placed in a stiff shoe (or a shoe with a stiffener) there is a smaller dorsiflexion moment applied to the hallux at the mpj (assuming the heel does not lift out of the shoe). In fact there may be no additional dorsiflexion moment from the shoe at the mpj because the heel, met head, and hallux are all on the same plane.

    So, I would say that the stiffener reduces dorsiflexion moments on the hallux and not necessarily creates a plantar flexion moment. There is no difference in the two when looking at net moment, but someone may get confused when they start looking for the plantar flexion moment from the stiffener.

    Cheers,

    Eric
     
  11. David Smith

    David Smith Well-Known Member

    Eric

    Yes that quick reply was a little lazy and inadequate. This diagram should do it. A picture is worth a thousand words eh!
     

    Attached Files:

  12. pgcarter

    pgcarter Well-Known Member

    Some TL2100 devices I have seen are pretty flexy....and may not be loading the mid foot very effectively...and if the forefoot rearfoot relationship is rectus...just exactly what are you addressing with "rear foot control" ?
    Regards Phill
     
Loading...

Share This Page