Analyzing How Skinfold Thickness Affects Log-Transformed EMG Amplitude-Power Output Metrics.

BACKGROUND

The purpose of this study was to determine whether accounting for skinfold thickness would reduce the variability observed on a subject-by-subject basis for the -intercept and slope terms derived from the log-transformed EMG amplitude-power output relationship. We hypothesized that using skinfold thickness as a covariate would reduce the subject-by-subject variability in the -intercept and slope terms and, therefore, indicate potential mean differences between muscle groups.

METHODS

Subjects had the skinfold from their three superficial quadriceps femoris muscles measured and then EMG electrodes placed over the three muscles. Thereafter, each subject performed an incremental single-leg knee-extensor ergometer exercise test to voluntary exhaustion.

RESULTS

The results indicated that using skinfold thickness as a covariate did not change the statistical outcome when comparing the mean values for the -intercept or slope terms across the three superficial quadriceps femoris muscles.

CONCLUSION

These findings suggest that there may be other factors that are influencing the subject-by-subject variability for the -intercept and slope terms, respectively.