Cardiovascular responses to isokinetic trunk exercise

Department of Physical Therapy, University of Texas Medical Branch, Galveston 77550.

Isokinetic trunk ergometers are relatively new devices. Because the stresses on the cardiovascular system when using these types of devices were unknown, the purpose of this study was to document the heart rate (HR) and blood pressure (BP) responses during a typical exercise session. Twelve subjects participated in three sessions of trunk flexion and extension exercises conducted on separate days. Exercises at one speed (ie, 60 degrees, 90 degrees, or 120 degrees/sec) were performed at each session. During each session, five 30-second exercise periods were separated by 60-second rest intervals. There were no differences in the HR and BP responses between exercise sessions at the three speeds. There was a progressive increase in HR to a value approximating 77% of predicted maximal HR by the end of the exercise sessions. Systolic blood pressure did not change from rest to exercise; diastolic blood pressure decreased initially and remained stable at the lower value throughout the exercise sessions. Several subjects reported light-headedness and dizziness during rest intervals. Because of the symptoms reported, we recommend that therapists monitor BP and observe patients for signs and symptoms of exercise intolerance when performing this type of exercise.