Optimum Thoracic Pad Placement

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By Marty Carlson, CPO, FAAOP

In the early to mid-1970s one commercial entity began to teach that the cephalad margin of scoliosis corrective/holding pads should be no more cephalad than the apex of the curve they were applied to. In the years since, that "rule" has gained considerable inertia, as it has been consistently part of teaching hundreds of orthotists how to treat scoliosis. The rule has been adhered to quite widely, but I'm not aware that it has the support of either clinical trials or mathematical model analysis. My own clinical experience, qualitative engineering analysis, and literature search indicated early on that such a rule was unwise. In fact, I feel that such a thoracic pad placement formula is clearly detrimental for some double curve (for example, right thoracic-left lumbar) combinations and for thoraco-lumbar curves. The biomechanics reasoning (with illustrative 3-D models) for this view was presented at the scoliosis symposium in Portland, Oregon. My own analysis indicates that thoracic pads should be centered at a level horizontal to the curve apex in most cases.

Unilateral Cervical Component for AIS Orthoses

Postero-lateral view of Tamarack's custom cervical component on a CTLSO. The stainless steel bar is welded to the superstructure posteriorly and coupled to the anterior bar by a vertical axis hinge.
Postero-lateral view of Tamarack's custom cervical component on a CTLSO. The stainless steel bar is welded to the superstructure posteriorly and coupled to the anterior bar by a vertical axis hinge.

At the same time as the Milwaukee has been recognized as the "gold standard" for treating adolescent idiopathic scoliosis (AIS) and as being the most adaptable (for managing sagittal abnormalities which often attend AIS) and adjustable design, orthopedists and orthotists have turned to alternatives. The reason is the neck ring, which has always been considered a very significant factor limiting acceptance of the Milwaukee orthosis.

In the early 90's Tamarack designed and built a substitute for the Milwaukee neck ring. Our reasoning was that a unilateral (left or right) cervical component of the correct design could perform both of the very important functions of the old-style neck ring: 1) The anterior-posterior mechanical linkage at the cephalad extremity of the orthosis greatly increases the structural integrity and pad placement options; 2) It serves as an alignment stimulus on the left (usually) or right side of the child's neck, depending on the curve pattern.

We reasoned that eliminating neck encirclement would be a significant step toward greater emotional-psychological and cosmetic acceptance for both parents and child. The Tamarack cervical component is made of metal to minimize bulk while maintaining excellent mechanical linkage integrity (rigidity).

Marty Carlson, CPO, FAAOP, has a masters degree in engineering mechanics and materials from the University of Minnesota and received his orthotic and prosthetic education at Northwestern University. He was director of habilitation technology at Gillette C