Cardiovascular responses during isokinetic muscle assessment in claudicant patients.

Background: Isokinetic dynamometry is becoming increasingly important for the assessment of muscle function in individuals with intermittent claudication. However, there is still little information available about the cardiovascular responses of these patients during this type of assessment.

Objective: To assess and compare the cardiovascular responses recorded during the assessment of muscle strength and endurance for two exercises commonly used in patients with IC (plantar flexion/dorsiflexion and knee flexion/extension).

Methods: The sample consisted of 17 claudicant patients with stable disease for at least 6 months. During the isokinetic dynamometer testing, non-invasive measurements of heart rate, blood pressure and double product at rest and at peak exertion were obtained according to specific protocols established for muscle strength and endurance assessment.

Results: Except for diastolic blood pressure, heart rate, systolic blood pressure and double product values rose during the exercise compared to the resting stage (p < 0.05). Elevations in heart rate and double product values were higher during knee extension/flexion than during plantar flexion/dorsiflexion (p < 0.05). Increases in heart rate were also higher during the endurance assessment protocol than during muscle strength assessment.

Conclusion: Isokinetic strength and endurance testing in patients with IC results in elevation of heart rate, systolic blood pressure and double product values during the exercises. These increases are higher during the muscle endurance exercises and in those involving greater muscle mass, suggesting that strength testing of small muscle groups causes less cardiovascular overload in these patients.