Preliminary investigation of residual-limb fluid volume changes within one day

Abstract

The purpose of this research was to investigate rates of residual-limb fluid volume change within one day for people with transtibial limb loss. Rates of fluid volume change during 30 min test sessions of sitting, standing, and walking activities were measured twice a day, once in the morning and once in the afternoon, on 12 regular prosthesis users with the use of bioimpedance analysis. Between test sessions, all subjects consumed food and drink, and subject activity ranged from low to high. The rate of fluid volume change within sessions ranged from -8.5 to 5.9 %/h (median: -2.2%/h). The rate of fluid volume change between sessions ranged from -2.7 to 0.9 %/h (median: -1.0%/h). The between-session rate of fluid volume change correlated highly with afternoon within-session rates of change (r = 0.9) but was not well correlated with morning within-session rates of change (r = 0.8). Subjects with peripheral arterial complications showed greater fluid volume loss rates during test sessions than between sessions. Rate of fluid volume change may be affected by sitting, standing, and walking activities; presence of peripheral arterial complications; being female; time since amputation; and wearing the socket without doffing for extended periods.

Figures

FIGURE 1

Electrode configuration for bioimpedance analysis.

FIGURE 2. Exemplary bioimpedance data collected during test sessions

The black dots indicate points during the 10 s stand interval after each 90 s walk that were used in analysis. The rate of fluid volume change was the slope of a linear fit to those five data points for each session.

FIGURE 3. Percent residual limb fluid volume change vs. time for all subjects tested

The arrowed lines illustrate the within-session fluid volume changes (AM and PM), and the dashed liner represents the between-session changes. Subjects are ordered from highest to lowest between-session rate of change (Between%/h).

FIGURE 4. Relationships between rates of fluid volume change

(A) Morning session (AM) data correlated moderately well with between-session data (r=0.8). (B) Afternoon session (PM) data strongly correlated with between-session data (r=0.9).

FIGURE 5. Rates of fluid volume change

Subjects with peripheral arterial complications (indicated with a *) showed greater fluid volume loss rates within sessions than between sessions. Subject identification #'s are the same as listed in TABLE 1.