Anatomical structure of the subcutaneous tissue on the anterior surface of human thigh.

The anterior thighs of 16 limbs from eight donated cadavers were observed using ultrasonic imaging and gross dissection with a specific focus on the subcutaneous tissue, which is considered an auxiliary element of locomotion. On ultrasonic imaging, the subcutaneous tissue was found to comprise multiple layers. The number of layers gradually decreased on progressing distally in the thigh. On gross dissection, a lot of fatty tissue and loose multiple laminar structures were observed in the medial and proximal areas. However, on progressing distally, these layers thinned out and became less fatty. Cutaneous nerves were apparent among the layers below the dermis. In addition, there were many associated fiber bundles between the dermis and muscle fascia, some of which appeared to be so-called skin ligaments that run through the subcutaneous tissue perpendicularly from the fascia to dermis, accompanying cutaneous nerve fibers and blood vessels. While identifying the peripheral cutaneous nerve fibers, several anastomosing rami and neural networks were recognized. These observations suggest that skin ligaments could be elements regulating motor restriction during muscular movement.