In reply
We thank Shadmi and Zisberg for their interest in our article and were pleased to see similar findings on the association between higher levels of mobility and shorter lengths of stay reported in their study. We also agree that practical recommendations for ambulation during this critical period are needed. An important underlying assumption is that not all inactivity during hospitalization is necessary or inevitable. Clearly, serious acute illness will require bed rest and reduced activity, but the overriding clinical impression of investigators in the field is that inadequate attention is given to methods to increase activity when clinically appropriate. There is strong evidence that disability among older persons is driven largely by illnesses and injuries leading to hospitalization and restricted activity.1 Motion sensor technology within the acute care setting will provide new capabilities to develop therapeutic guidelines for ambulation in hospital as well as examine its potential as a biomarker of recovery and response to treatment.