Manipulative therapy (MT), administered by certified physical therapists, encompasses manual techniques such as kneading, pressing, rubbing, and tapping the musculoskeletal system [1,2]. MT is a non-invasive physical therapy that promotes blood flow, alleviates pain, and enhances muscle flexibility [3]. It finds wide application for injury prevention, treatment, and relaxation [1]. However, studies evaluating the effects of MT using objective indicators are less abundant compared to other medical fields, with inconsistent results [4].Recently, we developed diffuse correlation spectroscopy (DCS), an innovative optical technology that allows non-invasive measurement of blood flow in local deep tissue [5][6][7][8][9][10][11]. Using DCS, we observed a significant increase in local blood flow on the targeted trapezius muscles for at least 5 min after MT without affecting systemic circulatory function [6]. Nonetheless, the contribution of increased blood flow to the primary clinical outcomes of MT such as relief of muscle stiffness remains uncertain. Moreover, the effects of MT on blood flow redistribution in the cutaneous and subcutaneous tissues above the target and neighboring muscles were not explored in previous single-channel DCS measurements [6,12], and require elucidation. This study aimed