Forearm and Biceps Circumferential Variations in Skin Tissue Dielectric Constant and Firmness

Nova Southeastern University, Davie, Florida, USA

Objective. To determine circumferential variations of skin tissue dielectric constant (TDC) and indentation force (FORCE) at arm sites frequently used to evaluate arm lymphedema. Background. Little is known about how these values depend on the circumferential position at which such measurements are made. We sought to provide initial data on this question by determining the extent of circumferential variability among healthy young adult women. Methods.Women (N=35, age 18-31 years with BMI of 17.4 to 37.2 Kg/m2) were evaluated by measuring TDC and FORCE at medial, anterior and lateral sides of the subject’s non-dominant forearm and bicep. The sites were 5 cm distal and 8 cm proximal to the antecubital fossa. TDC was measured at 300 MHz by touching skin for about 5 seconds with a coaxial probe. FORCE was measured in milliNewtons by recording the force needed to indent skin 1.3 mm. Results: There were small but statistically significant differences among circumferential TDC values at forearm (p=0.003) and among bicep sites (p Conclusion: Clinical assessments of TDC and FORCE are best done by standardizing and maintaining the same anatomical site when differences herein reported are of clinical importance. Further research on mature subjects and lymphedema patients is needed.