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Hi all,

student here, just wondering...

does a plantarflexed 1st ray increase the likelihood of functional hallux limitus?
my thinking is: if the metatarsal is already further through its available range of plantarflexion, then there is less metatarsal plantarflexion available to allow for adequate hallux dorsiflexion :confused:

is this plausible? or am i just being:pigs:?

thanks,
Apollus

 

Go to table of contents and click on functional hallux limitus. Many threads there for you to review.

Steven

 

The answer, as always, is "it depends".

Is metatarsal plantarflexion required for hallux dorsiflexion? What does the answer to that question depend on? That is also the answer to YOUR question.

 

I would have thought it depends on the stiffness of the plantarflexed first ray.

If its compliant, its going to dorsiflex with ground reaction force (GRF) and more likely be a FnHL.

If its stiff, its more likely to not dorsiflex significantly with GRF and therefore less likely to be a FnHL.

Rebecca

 

Apollus:

A plantarflexed first ray,by itself, does not increase the likelihood of functional hallux limitus (FnHL). FnHL is caused by excessive internal hallux plantarflexion moments that are greater than the external hallux dorsiflexion moments during propulsion, thereby preventing normal hallux dorsiflexion motion during propulsion. Most causes of FnHL can be traced back to mechanisms that increase the tensile force in the medial band of the plantar fascia such an increased subtalar joint pronation moments, increased medial longitudinal arch flattening and an elongated first metatarsal. If the first ray is plantarflexed and has increased dorsiflexion stiffness, then FnHL is unlikely to occur. However, if the first ray is plantarflexed and has increased dorsiflexion compliance, then FnHL is more likely to occur. Therefore, FnHL is caused by many factors, with a plantarflexed first ray not necessarily being a prime factor.

Hope this helps.

 

:welcome:

The answer to your question is - Yes it does increase the likelihood of FncHL. The probability is increased just like if you drive faster the probability, or likelihood, of dying if you crash, is increased. Not everyone does though because they avoided the forces that would have been fatal. Same with the low first ray, the probability is increased but the actual reality of the event depends on how the forces act on the relevant mechanisms and tissues.
Your job Apollus, should you decide to accept it, is to determine how those forces act on your specific patient.
This message will self destruct in 30 seconds:eek:

Good question

Regards Dave

 

:good: nice work Asher. For the reasons Kevin subsequently outlined.