Cardiovascular Responses to Static Assessments of Trunk Muscles

ABSTRACT.

Objectives: To investigate the cardiovascular responses to standard static assessments of strength and endurance of trunk extensor muscles.

Methods: Trunk extensor performances of 10 healthy men, age 48.2 ± 5.6 years, and 10 healthy women, age 49 ± 5.7 years, were assessed by means of a maximum static strength test [consisting in maximal voluntary contractions [MVC] performed with a specific dynamometer], and two static endurance tests [the Sorensen test, and a 50 percent MVC test]. Heart rate [HR], auscultatory systolic blood pressure [SBP], and diastolic blood pressure [DBP] were recorded throughout the tests.

Results: The MVCs induced significant increases of HR and SBP [mean peak values averaging 90 [female] to 95 [male] beats per minute [bpm] and 133 [female] to 141 [male] mmHg]. The HR, SBP, and DBP values increased significantly across time throughout both endurance static tests. At the end of these tests, mean HR, SBP, and DBP reached 114 to 122 bpm, 172 to 185 mmHg, and 112 to 120 mmHg, respectively. Genders differed significantly with regard to holding times [longer in females], but a gender effect was only found on SBP [higher in males]. HR and SBP increases were significantly higher in males than in female subjects.

Conclusions: The strength test seems less demanding than expected, though our results need to be confirmed. Standard static endurance tests yield sizeable functional stress on the cardiovascular system. Our study emphasizes the need to exclude subjects with cardiac trouble from such efforts and suggests the relevance of monitoring cardiovascular parameters if tests are performed until exhaustion.

KEYWORDS. :

• Isometric exercise
• cardiovascular system
• blood pressure
• heart rate
• spinal muscles

ACKNOWLEDGEMENTS

The authors thank A. Depas, A. Depaifve, A. Godet, P-A Absil, V. Tits, and A. Tits for their help, cooperation, and valuable assistance.