Kevin,
Thanks for your answer.
I understand the part about the forefoot valgus post preventing lateral
instability and narrowing the base of gait.
But I am confused regarding stride length. Does the forefoot valgus wedge
pronate the subtalar joint so the stance phase muscles have to fire longer,
and the midtarsal joint is unlocked to increase the range of motion and
allow the leg to go further forward prior to heel off; or is it that the
longer duration of the firing of the gastrocnemius allows for a greater
propulsion so the body is airborne longer, and therefore longer stride length?
Stanley
At 03:16 PM 12/5/04 -0800, you wrote:
>Stanley and Colleagues:
>
>Stanley wrote:
>
><<Does this mean that forefoot valgus posts, pronate the subtalar and
>midtarsal joints and allow the leg to come over the foot to increase the
>stride length?>>
>
>Forefoot valgus wedges shift the center of pressure laterally that then
>allows the gastrocnemius-soleus complex to have increased duration of
>contractile activity during propulsion without also causing supination
>instability of the subtalar joint during propulsion. One of the most
>easily measured results of this effect is an increased stride length.
>
>Sincerely,
>
>Kevin
>
>****************************************************************************
>Kevin A. Kirby, DPM
>Adjunct Associate Professor
>Department of Applied Biomechanics
>California School of Podiatric Medicine at Samuel Merritt College
>
>Private Practice:
>107 Scripps Drive, Suite 200
>Sacramento, CA 95825 USA
>
>Voice: (916) 925-8111 Fax: (916) 925-8136
>***************************************************************************
>----------------------------------------------------------------- This
>message was distributed by the Podiatry JISCmail list server
>
>All opinions and assertions contained in this message are those of the
>original author. The listowner(s) and the JISCmail service take no
>responsibility for the content.
>
>to leave the Podiatry email list send a message containing the text leave
>podiatry to [log in to unmask]
>
>Please visit http://www.jiscmail.ac.uk for any further information
>-----------------------------------------------------------------
-----------------------------------------------------------------
This message was distributed by the Podiatry JISCmail list server
All opinions and assertions contained in this message are those of
the original author. The listowner(s) and the JISCmail service take
no responsibility for the content.
to leave the Podiatry email list send a message containing the text
leave podiatry
to [log in to unmask]
Please visit http://www.jiscmail.ac.uk for any further information
-----------------------------------------------------------------
|