Mossberg KA, Greene B, Ohinata A, Eckert L, Tompkins T; University of Texas Medical Branch and the Transitional Learning Center, Galveston, TX, USA. kmossber@utmb.edu.

PURPOSE: Survival rates after brain injury have improved recently and more individuals with traumatic brain injury (TBI) are potential candidates for increased rates of morbidity and poor quality of life. Physical fitness is an important contributor to improved health related quality of life. Measurement of physical function in persons with TBI in reliable ways is essential given the cognitive impairments often accompanying TBI. The purpose of this study was to assess the reliability of graded exercise treadmill test to assess cardiorespiratory fitness in persons with TBI. SUBJECTS: Sixteen clients (11 male, 5 female) with TBI were recruited from a post acute residential treatment center. All subjects were capable of ambulation with or without an assistive device. METHODS: Subjects ambulated on a motorized treadmill while their heart rate, electrocardiogram, ventilation, and oxygen consumption was continuously monitored. The treadmill protocol followed was a modification of the Balke-Ware protocol. Maximum safe speed of walking was determined for each subject during a two-minute warm-up phase. After the warm-up phase the incline was increased 2% every minute thereafter. Reasons for stopping the test included the subject requested to stop or ambulation became unsafe, the subject reached peak oxygen consumption, the heart rate reached 85% of age predicted maximum and/or the subject achieved a respiratory quotient of 1.2. Each patient was tested twice, separated by 4-10 days, at the same speed and time of day. ANALYSIS: All dependent variables were analyzed using the intraclass correlation coefficient (ICC (2,1)) to determine the level of absolute agreement between the test and the retest for the peak response and during each minute of submaximal exercise. RESULTS: The ICCs for the peak responses were as follows: total ambulation time 0.81, peak heart rate 0.66, peak oxygen consumption 0.80, and peak minute ventilation 0.82. During the first 8 minutes of ambulation when most subjects still had the ability to walk, the ICCs for the submaximal responses ranged from 0.78 to 0.94. CONCLUSIONS: Monitoring peak responses can reliably assess adaptations to increased or decreased levels of physical activity. However, submaximal responses have equal or greater test-retest reliability. Individuals with TBI can perform an ambulatory treadmill test of cardiorespiratory fitness reliably. FUNDING SOURCE: The Moody Foundation. CONFLICT OF INTEREST: None.

Copyright 2004 by the American Physical Therapy Association

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