A few years ago, I attended a lecture regarding the interconnections of fascia throughout the entire body. I remember observing slide after slide of the fascia of the body that seemed to be one large mass that reached from hallux to cranium. I am reminded of this visual every time I observe gait. The relationship of each body part and joint is so important to keep in mind when trying to address pathology of the foot and ankle.
A primary example is the relationship of the 1st ray and the rearfoot. Which came first: the rearfoot eversion, the forefoot "supinatus", the dorsiflexed 1st ray or the limited 1st MPJ motion? Each of these segments does need to be addressed when treating any type of related pathology: plantar fascitis, HAV, 1st metatarsal cuneiform exostosis, functional hallux limitus, PT Dysfunction, etc. By addressing orthotic modifications to optimize the function/control of each of these segments, the overall function should improve. So, if the patient's primary symptom is 2nd metatarsal pain due to a dorsiflexed 1st ray, an appropriate thought process may include the following:
1) 1st ray needs to be plantarflexed---- cast with 1st ray plantarflexed and use minimum cast fill
2) Plantar fascia needs to be taken off stretch--- add Reverse Morton's extension and use minimal cast fill
3) Rearfoot eversion should be avoided--- use medial heel skive and deep heel cup
To read more on a study regarding the interconnected segments, see today's EJournal summary on a article by Harradine:
Harradine PD, Bevan LS. The Effect of Rearfoot Eversion on Maximal Hallux Dorsiflexion. JAPMA 90(8): 390-393, 2000.