BioSensics has developed a Physical Activity Monitoring System (PAMSys) that consists of a single wearable motion sensor that is worn on the torso. The objectives of this observational study are the following: 1) to test the efficacy of PAMSys for objectively assessing a persons risk of falling based on activity data measured during activities of daily living and 2) to test the efficacy of PAMSys for identifying precise early physical activity or functioning indicators of frailty in those who are pre-frail or frail as compared to non-frail controls.