Investigation of the effects of isokinetic knee assessment on cardiovascular parameters in middle-aged subjects

Abstract

The cardiovascular response to a routine isokinetic knee assessment was measured in 10 normal middle-aged subjects using continuous invasive arterial blood pressure and electrocardiographic monitoring. All subjects were pre-screened with a treadmill test, which yielded an average increase of 113% in resting heart rate, 47% in systolic blood pressure and 214% in calculated rate pressure product. The isokinetic assessment comprised strength tests at 60, 180 and 350° sec−1 (1.05, 3.14 and 6.11 rad sec−1) and a fatigue test at 240° sec−1 (4.20 rad sec−1). This assessment produced an average increase in heart rate of 90%, in systolic blood pressure of 65% and in rate pressure product of 216% over an average time of 6 min. Since these increases may stress the cardiovascular system, consideration should be given to pre-screening of middle-aged and older subjects with known cardiac risk factors prior to undertaking isokinetic assessment of strength and endurance in large muscle groups.