Table 1.

Quantitative ultrasound variables analyzed to evaluate the structural effects of percutaneous electrolysis on muscle tissue.

Variable	Description	Interpretation
A_Number	Number of affected areas detected in the ultrasound image after current application.	Reflects the appearance of visible structural alterations induced by electrolysis.
A_Area	Total area of the altered region after the intervention.	Assesses the magnitude of the effect induced by electrolysis.
A_Perimeter	Perimeter of the affected region, providing information about the boundaries of tissue alteration.	Indicates the extent of structural effects induced by electrolysis.
A_Convexity	Ratio between the perimeter of the altered region and the perimeter of its convex hull.	Quantifies the geometric regularity of the affected area; lower values suggest greater irregularity and tissue disruption.
A_Homogeneity:	Measurement of echogenicity uniformity in the image.	A reduction suggests increased heterogeneity in muscle structure induced by electrolysis.
A_Contrast	Represents the level of contrast between the treated region and the healthy tissue.	An increase indicates greater differentiation in the ultrasound signal induced by electrolysis.
A_ASM	Texture parameter reflecting pixel organization regularity in the ultrasound image.	A decrease suggests greater disruption of the muscle structure induced by electrolysis.
B_GLCM and B_GLDS	Set of variables derived from texture co-occurrence matrices.	Assesses the structural complexity of the tissue following electrolysis.

ASM: Angular Second Moment; GLCM: Gray-Level Co-occurrence; GLDS: Gray-Level Difference Statistics.