Orthotic posting and the triple interface

The "first ray cut out" seems to me like a mechanically-illogical orthosis modification for someone with, for example, a functional hallux limitus (Laird PO: Functional hallux limitus. The Illinois Podiatrist. 9:4, 1972). With a functional hallux limitus, the orthosis should be designed to decrease first ray dorsiflexion moments from ground reaction force (GRF). By cutting out the medial 10-15 mm of the anterior edge of the orthosis, you significantly reduce the ability of the orthosis to resist eversion moments from the foot. As a result, the orthosis will lose a significant amount of ability to generate external subtalar joint (STJ) supination moments on the foot which will tend to allow the foot to pronate more which will, in turn, increase the GRF plantar to the first metatarsal head and thereby increase first ray dorsiflexion moments.

In addition, since hallux dorsiflexion and first ray plantarflexion does not occur until the heel lifts from the ground, there will be rapidly decreasing pressure exerted from the foot on the orthosis plate after heel off, minimizing the mechanical effect of the first ray cut out again.

A much better mechanical solution for functional hallux limitus is to use a full width orthosis shell, use a rearfoot post, use anti-pronation modifications such as medial heel skives, minimal arch fills and stiffer plate materials and then use a reverse Morton's extension (i.e. 2-5 forefoot extension to sulcus) of 2-4 mm thick korex (or other similar material). I was taught to use the 2-5 forefoot extension for functional hallux limitus as a podiatry student at the California College of Podiatric Medicine (CCPM) in 1980. John Weed, DPM, lectured to us podiatry students about functional hallux limitus (and the difference between functional and structural hallux limitus) and the effective treatment of functional hallux limitus in 1980-1983 at CCPM.

By the way, for those of you who want a little bit of the early history of functional hallux limitus, Patrick Laird, DPM, who wrote the original paper on functional hallux limitus back in 1972, was formerly a professor of biomechanics at CCPM and he was one of my attendings during my surgery residency at the Veteran's Medical Center in Palo Alto, California. Pat was a brilliant surgeon and very knowledgeable in biomechanics. Unfortunately, he passed away a few years ago so I feel like someone needs to speak up for the things he did for podiatry. Pat was also instrumental in modifying the Reverdin-Green bunionectomy to allow for correction of IM angle deviation (Laird PO, Silvers SH, Somdahl J: Two Reverdin-Laird osteotomy modifications for correction of hallux abducto valgus. JAPMA, 78: 403-405, 1988). Pat's modification of Don Green's modification of the Reverdin's orginal first metatarsal head osteotomy technique is the technique I still use to this day for the majority of my bunion surgeries (now with cannulated screw fixation).

 

So who was the first to describe the first ray cut-out, Kevin (AKA Dr Pack Rat)?
http://www.podiatry-arena.com/podiatry-forum/showthread.php?t=30500