The rhomboid flap is a reliable, versatile, and widely used tool in head and neck surgery. Although its geometry is well described, the mechanics of the flap have not been scientifically investigated. For example, there is disagreement whether the maximum tension is located at the closure of the donor site or at the tip of the flap. An experimental model using piglets and stabilized force gauges has been developed to measure the distribution of tension in a standard Limberg flap (60 degrees rhomboid). Variables evaluated include the size of the rhomboid, the amount of undermining, and the position of the flap on the animal. Consistent measurements show tension at the closure of the donor site to represent the majority of tension around the flap (58% average); the size of the rhomboid and degree of undermining do not change relative tensions. A composite figure discloses the relationship of the initially outlined flap to the final result and quantifies the observable changes in the length of sides.