Changes in the PTI and MPP values after MP placement in each outcome group. The difference between two parameters differed significantly in each outcome group (p < 0.05). Note that the MPP of 4 feet increased after MP placement–3 rated the outcome as 1, while one rated it as no change, i.e. Subjective outcome rating: 1, worse; 2, no change; 3, improvement <50%; 4, improvement >50%. MPP, maximal peak pressure; PTI, pressure time integral.