Providing Real-Time Wearable Feedback to Increase Hand Use after Stroke: A Randomized, Controlled Trial

Abstract

After stroke, many people substantially reduce use of their impaired hand in daily life, even if they retain even a moderate level of functional hand ability. Here, we tested whether providing real-time, wearable feedback on the number of achieved hand movements, along with a daily goal, can help people increase hand use intensity. Twenty participants with chronic stroke wore the Manumeter, a novel magnetic wristwatch/ring system that counts finger and wrist movements. We randomized them to wear the device for three weeks with (feedback group) or without (control group) real-time hand count feedback and a daily goal. Participants in the control group used the device as a wristwatch, but it still counted hand movements. We found that the feedback group wore the Manumeter significantly longer (11.2 ± 1.3 h/day) compared to the control group (10.1 ± 1.1 h/day). The feedback group also significantly increased their hand counts over time (p = 0.012, slope = 9.0 hand counts/hour per day, which amounted to ~2000 additional counts per day by study end), while the control group did not (p-value = 0.059; slope = 4.87 hand counts/hour per day). There were no significant differences between groups in any clinical measures of hand movement ability that we measured before and after the feedback period, although several of these measures improved over time. Finally, we confirmed that the previously reported threshold relationship between hand functional capacity and daily use was stable over three weeks, even in the presence of feedback, and established the minimal detectable change for hand count intensity, which is about 30% of average daily intensity. These results suggest that disuse of the hand after stroke is temporarily modifiable with wearable feedback, but do not support that a 3-week intervention of wearable hand count feedback provides enduring therapeutic gains.

Movement diversity and complexity increase as arm impairment decreases after stroke: Quality of movement experience as a possible target for wearable feedback

“…The Manumeter is a wrist-worn device consisting of a six degrees-of-freedom (DOF) IMU with an accelerometer and a gyroscope (LSM6DSL; STMicrosystems, Switzerland), four magnetometers on four corners of the device, and an OLED display [16], [17]. For this study, we analyzed sensor signals from the IMU, sampled at 52.6 Hz obtained from a previous pilot study of the effectiveness of hand count feedback versus conventional home exercise [10]. Twentytwo participants (see overview of participants in Table I) wore the Manumeter once before the three-week hand-count feedback intervention and then once after the intervention.…”

“…Twentytwo participants (see overview of participants in Table I) wore the Manumeter once before the three-week hand-count feedback intervention and then once after the intervention. 10 data sets were lost because of data acquisition problems [18], [27]. Thus, in total, 34 data sets were used for the study.…”

“…Groups 2 (moderately impaired) and 3 (mildly impaired) are distinguished by whether they use their hand in daily life. Figure 3B shows the relationship between hand use, measured with the Manumeter, and UEFM score, replotted from [18]. Subjects with UEFM score ≥ 50 points (approximately) show a greater amount of hand use in the real world.…”

“…Escaping this vicious cycle is challenging due to multiple factors. Firstly, people generally don't begin to use their impaired arm voluntarily unless its function reaches at least half of its normal functional ability [10], [11], which aligns with the threshold hypothesis proposed by Schweighofer et al [9]. Secondly, even when individuals show improvement on clinical functional tests, such as the Action Research Arm Test (ARAT), this progress doesn't necessarily translate to increased arm use in daily life, indicating a "translation gap" between arm functionality and actual use [12].…”

“…We developed the Manumeter, a wrist-worn magnetic array that senses the movement of a magnetic ring worn on a finger, indicating the number of hand movements on a display [16]- [18], [10]. We used the Manumeter to test the hypothesis that real-time, daily feedback could promote hand use in daily activities [18]. We found that providing three weeks of such feedback promoted a small but a statistically significant increase in the amount of hand movements.…”