A review of activity monitors as a new technology for objectifying function in lumbar spinal stenosis

The purpose of this review article is to introduce the concept of activity monitoring, and to discuss the application of accelerometry in rehabilitation research and clinical practice using lumbar spinal stenosis as a model. Function is a complex concept, and changes in function have historically been challenging to measure. The International Classification of Functioning (ICF) defines two distinct components of function: capacity and performance. Capacity, the ability to perform a given task in a controlled environment can be measured through any number of existing functional measures. Performance, defined as activities performed on a day to day basis in the context of real life is challenging to measure, yet important in identifying the impact of pathology on real life. Recent advances in technology have allowed us to begin to measure performance, using activity monitors (accelerometers). Activity monitoring has the potential to change our concepts of outcomes, and as a result, expand our ideas about appropriateness of interventions in rehabilitation. Researchers and clinicians might benefit from using the new technology of activity monitors to measure the impact of intervention and to assess function. Therefore, this review will discuss the concept of activity monitoring and highlight potential uses for activity monitors in spine research and clinical care.