This study used three-dimensional (3D) scans to measure and analyse the skin strain distribution of the left lower limb during various running tasks, comparing the forward swing, maximum swing, landing, support and backswing. Two hundred female participants performed a standard standing posture and five running postures, dressed in shorts. With only two exceptions (part 5 and part 31), there were significant differences between the strain distributions and postures. The stretch ratios in the vertical direction were far larger than those in the horizontal direction. A more noteworthy lower limb movement produced a greater skin-stretch change. The thigh had significantly larger stretch ratios than the calf and hip in all five running tasks. During the swing forward, although the knee was bent, no large changes occurred in the skin of the knee but the thigh near the hip. Comprehensive and novel data were obtained using the 3D scanning system that could be used in running tight design.