Directional variance in skin movement

Skin tension is known to affect the amount of movement in normal skin and has been theorized to have a possible influence on burn scars. This study measured the directional variance in skin movement, which is related to this theory. Twenty adult female volunteers had 5 predetermined skin sites tested; these sites were on the ventral surface of the upper extremities (UE), from the shoulder to the wrist. A 1 kg axial traction force was randomly applied to each skin site in both proximal and distal directions. The skin was load-cycled 6 times before movement was measured with the use of a laser beam projection. Analysis was performed for each site, and pooled data was normalized for the entire UE. Distal skin movement was significantly greater than proximal movement at each of the 5 test sites and for the UE as a whole (P < .001). No significant differences were found among like-direction sites. Only subject height and length of UE correlated strongly (r = .88). This study demonstrates a difference in skin movement and discusses how these findings may relate to the theory that skin tension could be involved in burn scar contracture and hypertrophy.