To Sock or Not To Sock?
January 2005 Issue
Its been a common refrain of amputees for years, even in todays world of gel liners and total surface weight bearing sockets: "When my leg shrinks during the day, I just put another sock on." But is applying sock after sock after sock really the best way of adapting to volume change?
Consider this: when a limb loses volume, the bony prominences of the limb are not going to shrink. The loss happens entirely in the soft tissue areas. And since the soft tissue itself is not dispersed symmetrically throughout the limb, any volume loss that happens will not be symmetric either.
So what are we doing when we apply a sock (or two or five or more)? Were increasing the volume of the limb by the same amount everywhere. For a typical transtibial socket, imagine how much the condylar area gets squeezed in that scenario.
If the socket started out with a total surface weight bearing design, it certainly doesn't meet that description any more. And any type of liner that is worn with that socket is going to be subjected to those uneven pressures, too. A liner designed to accept even pressure across its entire surface is not going to last nearly as long when it is forced to take all of the pressure in one or two small areas.
The solution is to add volume only to the areas where it has been lost. Fortunately, many manufacturers today offer gel pads for the purpose of accomplishing this exact goal. The pads can be easily applied by the patient when volume is lost, and easily removed when the limb returns to its original volume. The key is to make sure that the patient understands exactly where to apply them.
Be sure to explain to the patient that, although volume loss will sometimes result in discomfort on the limb, the area where discomfort is felt is usually not the area where volume has been lost. A pad will only be effective if it is placed onto the area where volume has been lost. For example, for transtibial amputees, explain to them that the area most likely to lose volume is the area at the back of the leg, even though the looseness may be felt on the front of the leg at the tibia.
Benefits of Selective Padding
By adding pads in this manner, the total surface weight bearing design can be preserved, the gel liner will not be subjected to undue stress, and - most importantly - the patient will continue to experience the comfort of equal pressure across the entire limb, instead of discomfort across the bony areas. Socks (or any other products that apply an equal thickness around the entire limb) cannot achieve these goals. Using selective padding to replace volume in the exact area where it was lost is the most effective way of addressing the volume fluctuation that all amputees experience.
Raymond Francis, CP, is a certified prosthetist with over 40 years of experience. He is the chief prosthetist for Ohio Willow Wood and works extensively on research and product development.