The negative consequences of immobility during hospitalization are numerous, profound, and well-documented, including pressure ulcer formation, longer lengths of stay, muscle weakness, increased risk of falls, loss of independence, and reduced quality of life. Barron Associates’ wireless Patient/Resident Mobility Tracker (PREEMPT) provides an effective, accurate, noninvasive, and practicable method for automatically documenting patient mobility, providing the desired activity and body posture information that is relevant in both hospital and senior care settings. The PREEMPT device was evaluated in a clinical study using both healthy participants and hospital patients to evaluate the accuracy of its activity, mobility, and posture tracking algorithms. All outcomes were statistically equivalent truth captured via video. A usability/user-acceptance study indicated that the device was comfortable (many were unaware it was being worn at all) and accepted by patients.