Slip and fall is a major cause of injury in the elderly and outdoor workers. This paper presents the development of a wearable knee assistive device aimed to prevent slip-induced falls. The proposed novel approach relies on providing active assistance to the trailing leg during slip onset. The assistive device, when slip is detected and device is activated, actively extends the knee of the trailing leg creating contact with the ground. This immediately extends subject's base of support and helps with balance recovery. The lightweight device is powered by compressed CO2 gas from a small cartridge that can be used for a single slip assistance and easily replaced. The results of device characterization and human subject testing demonstrate that the device can assist with rapid knee extension during gait, forming an active slip and fall recovery strategy.
Self-weighing is consistently associated with more effective weight control. However, patterns show that participants disengage from their weight control behaviors following weight gain. Women with BMIs in the overweight/obese range (N = 50) enrolled in a long-term behavioral weight loss program completed ecological momentary assessment (EMA) surveys immediately after their daily weigh-ins. Nightly EMA surveys and self-monitoring data through Fitbit measured their weight control behavior that day. On days when participants gained weight (vs. lost or maintained), they reported more negative mood, more guilt/shame, and lower confidence in weight control. Motivation following daily weight gain depended on participants' overall satisfaction with their weight loss so far: more satisfied participants had marginally higher, but less satisfied participants had marginally lower motivation in response to daily weight gain. Greater guilt/shame and lower motivation after the weigh-in predicted less effective weight control behavior that day (e.g., lower likelihood of calorie tracking, fewer minutes of physical activity). Results demonstrate that even small weight gain is distressing and demoralizing for women in BWL programs, which can lead to goal disengagement. These findings have implications for future BWL interventions, including the potential utility of just-in-time adaptive interventions to promote more adaptive responses in the moments after weigh-ins.
