Microprocessor-based ambulatory activity monitoring in stroke patients


Medicine & Science in Sports & Exercise: March 2002 - Volume 34 - Issue 3 - pp 394-399
CLINICAL SCIENCES: Clinical Investigations

MACKO, R. F., E. HAEUBER, M. SHAUGHNESSY, K. L. COLEMAN, D. A. BOONE, G. V. SMITH, and K. H. SILVER. Microprocessor-based ambulatory activity monitoring in stroke patients. Med. Sci. Sports Exerc., Vol. 34, No. 3, pp. 394–399, 2002.

Purpose: Recovery of ambulatory function after stroke is routinely assessed using standardized subject- or observer-rated instruments that do not directly measure ambulatory activities in the home-community setting. Accuracy of conventional pedometers in stroke patients is not established, limiting their application in mobility outcomes monitoring. This study investigates the accuracy and reliability of a mechanical pedometer versus microprocessor-based step activity monitoring (SAM) in gait-impaired hemiparetic stroke patients.

Methods: Accuracy and test-retest reliability of ankle-worn SAM and belt-worn pedometer were tested directly against hand tallied stride counts and cadence during a battery of timed walks in 16 chronic hemiparetic stroke patients. Patients performed replicate 1-min floor walks at self-selected and fastest comfortable paces, and two 6-min walks on separate days.

Results: SAM cadence and total stride counts are more accurate than pedometers during 1-min walks at self-selected (99 ± 1 vs 87 ± 11.3%, mean ± SD, P < 0.01); fast pace (98 ± 2.3% vs 85 ± 15%, P < 0.01); and repeated 6-min walks performed on separate days (99 ± 1% vs 89 ± 12%, P < 0.01). Although SAM is highly reliable (r = 0.97, P < 0.0001) and accurate in all patients under every walking condition tested, the mechanical pedometer demonstrates this high level of accuracy in only half of stroke patients and has poor test-retest reliability (r = 0.64, P < 0.05).

Conclusion: SAM, but not the conventional pedometer, provides accurate and reliable measures of cadence and total stride counts in hemiparetic stroke patients. Portable microprocessor-based gait monitoring offers potential to quantitatively measure home-community-based ambulatory activity levels in this population.

Baltimore Veterans Affairs Medical Center Geriatrics Research, Education, and Clinical Center, Baltimore, MD; The University of Maryland School of Medicine Division of Gerontology, Departments of Neurology, Physical Therapy, and School of Nursing, Baltimore, MD; The Prosthetics Research Study, Seattle, WA; and Departments of Orthopedics and Rehabilitation, University of Washington, Seattle, WA

Submitted for publication December 2000.

Accepted for publication June 2001.

©2002The American College of Sports Medicine