ACCURACY OF FUNCTIONAL TESTS FOR IDENTIFYING ANTICIPATORY ACTIVATION OF THE LUMBOPELVIC MUSCLES

ABSTRACT

Introduction:

Anticipatory adjustments (pre-activation) of the deep trunk muscles increase lumbopelvic stability. Previous studies have shown that asymptomatic individuals may experience delays in the start of muscle activation, as well as functional physical alterations. However, there are no studies that assess whether physical and functional tests (PFT) are able to identify changes in early activation of the lumbopelvic stabilizer muscles.

Objective:

To assess the levels of sensitivity, specificity and accuracy of a set of physical and functional performance tests to detect changes in anticipatory activation of the transversus abdominis/internal oblique muscles (TrA/OI) and lumbar multifidus (ML) during a task of fast shoulder flexion movements (FSFM) .

Method:

Twenty-seven volunteers, asymptomatic for low back pain, with a mean age of 23.8 (Standard deviation: 2.2) years, participated in the study. They were submitted to PFT and FSFM to determine the initial activation time of the deep trunk muscles through surface electromyography. Sensitivity and specificity were determined, and accuracy was analyzed by the ROC (Receiver Operating Characteristic) curve and chi-square test for comparisons between percentages (p<0.05) .

Results:

Anticipatory activation was the condition that occurred most frequently in the group as a whole, and in both genders, with the exception of TrA/OI in females (χ^{_{2=0.28/P=0.58). Among all the PFT assessed, the repetitive trunk flexion-extension test showed the highest values for sensitivity, specificity and area under the ROC curve (0.75; 0.73; 0.74, respectively).}}

Conclusion:

Among the PFT evaluated, the repetitive trunk flexion-extension test showed acceptable levels of accuracy for identifying changes in the activation of deep trunk muscles in volunteers who were asymptomatic for low back pain. Thus, the repetitive trunk flexion-extension test can be used clinically to predict changes in the activation of deep muscles of the trunk.

Keywords:
electromyography; stabilization; physical fitness; lumbosacral region