Gait / Running Talk: Functional Hallux Limitus.
(*2 pictures attached today, toggle between the two and then read on. PS: the subheader for the photo suggests they recommend a Cheilectomy in many cases.. This was typing that came with the photo. This is not our recommendation in many cases. Please ignore those two lines of type for now. TGG)
It is often though from an evaluation perspective that hallux limitus is a loss of the big toe extending on the forefoot (metatarsal head), such as seen in the picture above. It is after all the easiest way to assess the joint, however it is not a true functional assessment, rather a passive ROM assessment. Keen observers will realize that under more functional circumstances, after planting the foot on the ground, the big toe will be affixed to the ground and the limitation will come as the person attempts to move the body over that joint. With a hallux limitus the 1st metatarsal will not be able to roll downwards on the phalanx (big toe) concavity and gain purchase on the ground. This can come from joint arthrosis or some of the functional problems we have discuss in our last 2 blog posts. This downward roll and glide, plus the body mass moving over the axis, is “functional extension” at that joint (as opposed to passive assessment function of the joint as seen in the first picture above). This joint can be referred to as the Windlass joint. Here we have the concave rounded metatarsal head (see 2nd picture) rolling up but sliding down withing the concavity of the hallux/ big toe (roll and glide are normally in opposite directions if the axis of joint centration can be held, in functional hallux limitus this centration axis is lost, hence the limitation) . This roll and glide in descending the metatarsal head to the ground is what we refer to as “medial tripod anchoring”. Disruption of this roll and glide at these joint surfaces through this extension movement to get the metatarsal head to the ground can be found with both Functional or Ablative (true) Hallux Limitus (aka “turf toe”). Failure of this biomechanical mechanism leads to insufficient medial tripod, aberrant toe off mechanics, probably pain, and risk for bunion and hallux valgus formation (because when the medial tripod is not anchored the functional mechanics of the adductor hallucis muscle changes and ends up pulling the hallux laterally).
Just taking you through a more functional perspective on hallux limitus. It is not as simple as “the joint is stuck”. And forcing the range won’t make it unstuck ! It will just create more dorsal bony abutment at the top of the joint, and pain. If you have any chance of fixing this monumentally misunderstood problem, you must understand this blog posting, and the last two blog posts. To fix this problem, if it is still functional and not ablative (fixed and permanent), you will have to use your brain and not your fingers !
On another day we will talk about the cluffy wedge that you see under the big toe (hallux) in the picture above. We will give you our perspective on the device, how we make our own version of a wedge and some of our concerns for its use.
Alot of our patients joke around when they come in to see us with a problem. We like humor in our offices. Their joke frequently is, “must be something wrong with that big toe again !”….. even if it is shoulder or neck pain. And interestingly, alot of the time they are somewhat right. If you screw up toe off, the rest of the movement is compensation.
The Big toe, …… it is often on the menu.
Shawn and Ivo