Various implementations of a patient monitoring assembly may be useful in preventing pressure ulcers, monitoring of air cushion inflation, estimating physical activity and energy expenditure and managing body weight of a patient seated on the assembly. The patient monitoring assembly may be installed on a manual or powered wheelchair, for example, and continuously monitors and provides feedback to the patient and/or caregiver about whether the patient is engaging in pressure relief activities while seated on a cushion of the assembly, whether the patients activities are in accordance with clinical guidelines for pressure relief, the amount of calories expended over a period of time and the weight and weight distribution of the patient seated on the assembly. The feedback may be provided in substantially real time via an interface on the wheelchair and/or via a remotely located computing device.