Arm Ergometry in Stroke Patients-Evaluation of Fitness with Single Arm Ergometry and Its Relation to Grip Strength.

[Objectives] Although the aerobic power of stroke patients has been studied with bicycle ergometry or treadmill exercise, they are not suited to moderate-to-severely involved patients. Arm ergometry (AE) is potentially more widely applicable to the disabled. The purposes of this study are to examine methodological issues of AE and compare exercise responses of stroke patients to normal controls.<br>[Methods] AE was performed with Cybex MET 300 ergometer, and heart rate (HR) and oxygen consumption (VO₂) were monitored with a Morgan Magna 88 system. The work rate was increased by 1 watts/3sec. in young adults and 5 watts/min. in strokes and matched controls till exhaustion.<br>1) Reproducibility was examined in 15 young adults (mean age: 27.7yr) and 8 strokes (mean age: 58.8yr). In the former, the differences between single and bilateral AE, and between right and left sides were also studied.<br>2) With single AE, 87 strokes (mean age: 58.4yr) were compared to 35 matched controls (mean age: 59.9yr).<br>3) The relatioship between aerobic power and muscle strenght was studied.<br>[Results and discussion] 1) The intraclass correlation coefficients of two trials were over 0.83 for maximal VO₂ (VO₂max) and 0.70 for maximal HR (HRmax). 2) Single AE VO₂max corresponded to 70 -80% of bilateral AE VO₂max. 3) VO₂max and HRmax were not significantly different between the two sides. 4) VO₂max and HRmax were not significantly different from controls, but HR-O₂ coefficient or the regression coefficient between HR and VO₂ were lower in strokes (Student t-test, p<0.05). It is suggested that differences are difficult to detect in maximal exercise since it is more limited by peripheral (muscular) factors, and hemiplegics are well conditioned to use their sound arms. On the contrary, differences are easier to detect in submaximal exercise that is more limited by central (cardiopulmonary) factors, as reflected by lower HR-O₂ coefficient. 5) VO₂max and HR-O₂ coefficient were lowest in the wheelchair dependent group, followed by wheelchair independent, household ambulatory and community ambulatory groups (Kruskal Wallis, p<0.05). 6) No complications were observed. 7) 61% of the variance of VO₂max was explained by grip strength.<br>[Conclusion] The aerobic power of strokes can be safely and reliably measured with single AE. There is cardiopulmonary deconditioning as evidenced by lower HR-O₂ coefficient. Grip strength could be a good predictor of VO₂max measured with single AE.