Active v. Passive

[Guest guest]

I'm totally outside the box on this. Once the expertise of our

orthotist had been thrown into doubt, I began viewing our " ups and

downs " with Clara's STARband with an empirical eye, aiming to

maximize the " ups. " Surveying the spectrum of opinion like

yourself, I began to disregard the active-passive distinction as

marketing hubris, and sought understanding on a different basis.

There *should* be more confusion among the Hanger and STARband

orthotists, because the distinction breaks down logically along wider

product lines. Consider the General Information given for the

Clarren helmet, the original and definitive " Passive " helmet <http://

www.orthomerica.com/products/cranial/clarren.htm>:

- Modified to full symmetry as minimal adjustment is available in liner

- Looser initial fit held in place with chin strap

- Less frequent follow-up required

and compare that to the Orthomerica's preeminent " Active " offering,

the STARband:

- Modified to full or partial symmetry

- Considerable adjustments available through removal of liner material

- Requires frequent follow-up for ongoing adjustments

If you order a STARband " modified to full symmetry, " and only make

symmetrical adjustments for head growth, not squareness of fit, is

that not also passive? I think the orthotists would say yes, but

their pragmatism, while frequently evident in discussions with

parents, would be at odds with the authoritative product definitions

of the manufacturer.

For we the consumers, the pragmatic determination needed is a

prediction of effectiveness. Even a passive helmet must be " active "

sometimes, or else it would be useless.

But I specifically had a STARband, a STARband that worked sometimes,

and sometimes not. I swallowed my disappointment and kept

communication with the orthotist as open as possible. Finally I

concluded that the helmet's " action " was to the torque the skull

plates into a more symmetrical angular relationship, then hold that

shape as long as possible while new growth rounded out the angles.

In the absence of either growth or torque, no correction.

Conversely, I would re-define " passivity " as the exertion of less

forceful, less constant torque. The difference is a matter of

degree, but the definitive sign I would use to distinguish the two is

reactive hyperemia that only just manages to resolve during a

helmet's off hour, on the first day following an adjustment. That's

the maximum pressure you'd ever want on the skin, and if properly

directed (on prominent points), a mighty torque.

--

Thad Launderville

Montpelier, VT

Clara age 2, STARband grad

On Apr 19, 2010, at 10:24 PM, Rapp wrote:

> I've spoken to the cranial-facial surgeon, parents on this board,

> and 3 different orthotists at Hanger. I still cannot get a

> satisfactory definition of the difference between an active and

> passive band. You seem very knowledgeable and obviously had your

> ups and downs with a band for your daughter. In your experience

> and discussions with your orthotist what would you say the true

> difference is? I'm really at a loss, even when I google it I get

> so many different definitions and opinions. I would appreciate

> your input. Thanks.

>

>

>

> On Mon, Apr 19, 2010 at 5:07 PM, Thad Launderville

> <p38thadl@...> wrote:

[snip]

> [...] I think a rotating " active, " or gradually reconforming helmet

> like the DOC Band or STARband, is even worse than a well-fitting

> " passive, " or symmetrical helmet. The former follows the

> circumference of the deformity, more or less, so when it rotates, you

> get " passive " type, light contact in flat areas, where there ought to

> be none. With an actual passive helmet, the shape is more rounded,

> so (I imagine) the void space is largely preserved. While neither

> exerts enough force to hold the plates of the skull in any particular

> shape, the net transient forces in the passive helmet should trend

> more toward correction.

>