Affiliations: Hardin-Simmons University, Department of Physical
Therapy, Abilene, TX 79898, USA | Rice University School of Engineering, Houston, TX
77005-1847, USA | Valley Baptist Medical Center, 2224 Benwood Drive,
Harlingen, TX 78550, USA | University of Texas Health Science Center,
Instrumentation Services, 7703 Floyd Curl Drive, San Antonio, TX 78284,
USA | Rehabilitation Medicine, The University of Texas
Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78284, USA
Abstract: {\it Objective:} To measure test-retest reliability of physiological
responses during submaximal wheelchair downhill and horizontal treadmill
ergometry. {\it Design:} A test-retest design was used on a convenience sample.
Four male and three female non-wheelchair users, (22--43 years of age)
propelled or coasted in a wheelchair under steady-state conditions. Four minute
work bouts were performed at 1, 2, 3, and 4 km/hr. (0.62, 1.24, 1.86 and 2.5
mph, respectively) at
0^\circ,-2^\circ, and
-4^\circ. Subjects were studied twice
under each of the 12 conditions. Six tests were performed daily, with testing
occurring over four days. Dependent variables included oxygen consumption,
minute ventilation and heart. Intraclass correlation coefficients were
determined for each set of paired tests. {\it Results:} Intraclass correlation coefficients were high for
absolute VO_{2}(R= 0.84-0.99),
V_{\rm E} (R= 0.86-0.98) and HR (R=
0.95-1.0) over the range of 4 speeds and 3 inclinations studied. On
average, % to test 2 were less than 3%. {\it Conclusion:} At the treadmill speeds and inclinations (positive
and negative) studied in this investigation, untrained wheelchair users
responded in a physiologically reliable manner.
Keywords: wheelchairs, oxygen consumption, negative work
