CARDIOVASCULAR STRESS IN ISOKINETIC TRUNK STRENGTH TEST

Study Design. In this experimental study, the participants served as t heir own controls. Objective. To estimate cardiovascular stress in iso kinetic trunk extension-flexion strength test. Summary of Background D ata. Thirty-one women with low back or neck pain who participated in t he physical reconditioning program were the study participants.Methods . Trunk extension and flexion strength was measured at three angular v elocities with heart rate recording and standard graded submaximal bic ycle ergometer test. Power output at the maximal age-predicted heart r ate level was estimated separately by trunk extension-flexion and bicy cle ergometer tests. Results. Torque decreased and heart rate and powe r increased with angular velocity (P < 0.0001). Power and heart rate v alues at the highest angular velocity of 120 degrees s(-1) in isokinet ic trunk strength testing were comparable to those measured during bic ycle ergometer test at the submaximal level. In trunk strength testing 13 subjects exceeded the power and 23 subjects exceeded the heart rat e they achieved in the bicycle ergometer test. Power output at the max imal age-predicted heart rate level estimated by isokinetic trunk stre ngth test and bicycle ergometer test had a clear correlation 0.76 (con fidence interval 95% 0.55-0.88. Conclusions. The cardiovascular capaci ty is an important factor-limiting performance in isokinetic trunk str ength testing, particularly at high velocities. Patients with suspecte d heart problems need special attention. Heart rate recording may help estimate degree of effort.