The purpose of this study is to determine the effects of daily feedback about physical activity (number of bouts of walking, duration of bouts, total walking distance, average and fastest walking speed) and walking average speed compared to feedback about walking speed only on walking-related outcomes during inpatient rehabilitation for stroke. For the first time, daily walking and other exercise will be monitored by bilateral triaxial accelerometers on the ankles. Activity-recognition algorithms will analyze the inpatient sensor data and return a summary to the participants at each site.

Wireless Sensor System The inertial sensor system and activity-recognition algorithms were previously described and tested for short-term reliability. Three sets of triaxial accelerometers (Gulf Coast Data Concepts, Waveland, MS) were mailed to each site's coordinator. Therapists placed one sensor on each ankle before participants got out of bed each morning and removed them once they were in bed at the end of the day; sensor use during weekends was optional. A soft snap band secured each sensor proximal to the medial malleolus, flush against the bony tibia. Every night, sensors were plugged into a local computer to recharge while accelerometer data were uploaded to the central server at UCLA for secure storage and processing. Sensor Calibration and Data Processing In recognition of the variations in gait speed and stand and swing symmetry that occur in patients who need inpatient rehabilitation after stroke, we chose to generate individual templates of each participant's gait from a pair of standardized walks. On study entry participants performed two stopwatch- timed 10-meter walks at self-selected casual and safest fast walking speeds. A hybrid classifier employing dynamic time warping and Naïve Bayes algorithms generated statistical models of each participant's gait based on the two walks. Repeat walks were performed and the templates updated weekly for the remainder of each participant's rehabilitation stay to account for expected changes in gait parameters.

Inclusion Criteria:

• Admission for acute inpatient rehabilitation of a first stroke (or second stroke after full recovery from prior TIA/Stroke)
• Time from onset of stroke to admission for rehabilitation < 35 days
• Stroke from any cause (thrombotic infarct, cardioembolus, intracerebral hemorrhage) that includes unilateral hemiparesis. Hemiparesis means less than / equal to 4/5 strength by the British Medical Council scale for hip flexion tested supine and for knee or ankle flexion and extension (scores less than / equal to 22 of 25 possible points)
• Ability to follow simple instructions, especially to understand verbal reinforcement about activity.
• Independent in mobility prior to admission by the Barthel Index.
• Able to walk with no more than physical assistance of 2 persons for at least 5 steps (for example, 3 strides of the left leg alternating with 2 on the right leg). Subjects can use any type of assistive device and brace needed.
• Able to understand and repeat information related to the Informed Consent. The subject signs a Consent form.

Exclusion Criteria:

• Current medical disease that will limit physical therapy at the time of randomization or limited walking prior to the stroke, such as serious infection, DVT, orthostatic hypotension, > stage 2 decubitus ulcer of buttocks or legs, congestive heart failure, claudication, and pain with weight-bearing or walking. Subjects can be entered if a complication resolves within 7 days of admission screening.
• Aphasia with inability to follow 2-step directions during therapeutic instructions or answers Yes/No to questions with < 75% accuracy related to personal health and symptoms.