Is an Ambulatory Biofeedback Device More Effective than Instructing Partial Weight-Bearing Using a Bathroom Scale? Results of a Randomized Controlled Trial with Healthy Subjects

Abstract

So far, there have been no high-quality studies examining the efficacy of outpatient biofeedback devices in cases of prescribed partial weight-bearing, such as after surgery on the lower limbs. This study aimed to assess whether a biofeedback device is more effective than using a personal scale. Two groups of healthy individuals wearing an insole orthosis were trained to achieve partial loading in a three-point gait within a target zone of 15-30 kg during overground walking and going up and down stairs. The treatment group (20 women and 22 men) received continuous biofeedback, while the control group (26 women and 16 men) received no information. Findings were compared in a randomized controlled trial. Compliance with partial loading without biofeedback was poor; on level ground and stairs, only one in two steps fell within the target area, and overloading occurred on at least one in three steps. The treatment group reduced the percentage of steps taken in the overload zone to ≤8.4% (p < 0.001 across all three courses) and achieved more than two-thirds of their steps within the target zone (p < 0.001 on level ground, p = 0.008 upstairs, and p = 0.028 downstairs). In contrast, the control group did not demonstrate any significant differences in the target zone (p = 0.571 on level ground, p = 0.332 upstairs, and p = 0.392 downstairs). In terms of maintaining partial load, outpatient biofeedback systems outperform bathroom scales.

Keywords: biofeedback; evidence-based medicine; orthosis; partial weight-bearing; pressure sensor; rehabilitation.

Figure 1

The device outputs loads under 20 kg with a green light (a) and loads over 20 kg with a red light (b), accompanied by an audible alarm sound. The removable sensereader is located on the outside of the orthosis. This makes it easy to see and ensures that it does not get in the way while walking.

Figure 2

Diagram of the study’s design (BF = biofeedback).

Figure 3

This classification was determined by the authors. It is based on Warren’s preliminary research where patients continue to exert a load after an alarm is triggered due to a physiological response time of 150 to 250 milliseconds [27,28]. This response leads to excess weight on the injured limb. To address this, it is recommended to set the alarm slightly below the maximum weight-bearing limit to account for this delay and additional loading.