ORLANDO, Fla. — Intermittent doffing can reduce fluid loss in the limb for some prosthesis users, particularly those with fleshy limbs, according to study results presented at the American Academy of Orthotists and Prosthetists Annual Meeting and Scientific Symposium.
“Walking is good. Standing is bad. Sitting with a donned prosthesis may be good or bad – it depends on the participant,” Joan E. Sanders, PhD, a professor in the Department of Bioengineering at the University of Washington, said, here.
Joan E. Sanders
Sanders and colleagues wanted to determine the effect volume changes in the limb had on users’ activity and self-reported outcomes, and to evaluate intermittent doffing as an accommodation solution for volume and fluid loss. The presentation was one of the winners of the Thrandhardt Lecture Series awards.
In the study of 30 transtibial amputees with a K-level of 2 or higher, about half of the participants used socks for accommodation. The researchers monitored sock use for 2 weeks and used the information to distinguish between accommodators — those who change socks during the day — and non-accommodators, or those who do not.
They measured the fluid change as patients went through five cycles of sitting, standing and walking. Sanders said of particular interest was the fluid change between cycles of activity, during which participants were told to go about their normal activities, including any donning or doffing of the prosthesis.
The results showed 77% of participants lost fluid volume between morning and afternoon activity sessions. The researchers also found as doffing time increased, the amount of fluid lost between sessions decreased. Non-accommodators spent less time on their feet than accommodators, but spent more time doffed. In addition, non-accommodators had higher self-reported outcomes than accommodators, but the change was not statistically significant.
Sanders said temporary doffing throughout the day kept fluid volume levels in an acceptable range.
In a second, 6-hour study conducted outside the lab, Sanders and colleagues measured limb fluid volume among 13 patients with a portable system. The study was conducted during 3 test days, each composed of three cycles of activity. The participants underwent both high and low activity stages, with a donned and doffed prosthesis.
The results showed the rate of fluid volume is greater earlier in the day compared with later in the day. They also showed participants had a smaller reduction in limb fluid volume during intervals with high activity than intervals with low activity.
The researchers found three responses to intermittent doffing among patients: six patients had less volume loss with intermittent doffing; three patients had more volume loss; and four patients had day-to-day variability of response. Further examination showed the patients who benefited from intermittent doffing had fleshy limbs. The researchers also posited the use of an elevated vacuum system after a period of high activity could aid in limb fluid volume recovery.
In a recent and related study, Sanders and colleagues found the thickness of socks used for limb volume accommodation changes non-linearly over time for amputees. – by Amanda Alexander
Sanders J, et al. Paper #TL2. Presented at: American Academy of Orthotists and Prosthetists Annual Meeting and Scientific Symposium; March 9-12, 2016; Orlando, Fla.
Disclosure: Sanders reports no relevant financial disclosures.