*Methods and Tools for Assessing Muscle Asymmetry in the Analysis of Electromyographic… DOI: http://dx.doi.org/10.5772/intechopen.103061*


#### **Figure 15.**

*Measurement results from 12 muscles (sets Xn and Yn).*


#### **Table 8.**

*Results of the calculated correlation coefficient.*

#### **Figure 16.**

*Histograms of muscle-dependent values of correlation coefficients.*

#### **6.2 Application of the obtained results**

**Figure 17** shows a comparative interpretation of the results obtained from the measurement of muscle strength and the correlation analysis of the measurement results using the available apparatus of the EMG signals.

#### **Figure 17.**

*Comparison of the results obtained from the measurement of muscle strength and the correlation analysis of the measurement results of the EMG signals using the existing apparatus.*

As can be seen from the figure, in the first case, the measurement results are presented separately for each muscle in the form of histograms or graphs. However, sometimes the results obtained from the right or left side of the same muscle are inconsistent, making this comparison difficult. On the other hand, because the diagnosis is based on the maximum value, it is difficult to observe and compare the tendency to asymmetry in other muscles. This is also reflected in the comparison of different measurement results.

The results obtained by calculating the correlation coefficient are not only simpler in terms of visual observation, but also easier to compare. It can be easily deduced from the graph that the biceps femoris muscle and the gastrocnemius muscle are already prone to asymmetry in the medial part muscles (**Figure 17**), and this is important information in determining subsequent treatment procedures.

#### **6.3 The result**

A correlation analysis method has been proposed that allows the determination of this asymmetry on the basis of EMG signals and the judgment of its level in different measurements. For this purpose, 12 signal results from three main muscle types covering the lower extremity were used, and the asymmetry was determined by calculating the correlation coefficient of the samples. This allows to easily compare the results from a visual point of view, as well as to determine the level of asymmetry in other muscles.
