The diaphragm is an essential respiratory muscle that accounts for 70% of the inspiratory function during stable breathing. Diaphragm weakness leads to decreased thoracic mobility due to inspiratory assist muscles overuse. It is closely related to respiratory dysfunction. This study aims to define the effect of TECAR therapy using Winback on diaphragm movement and chest mobility in adults with limited chest mobility. Thirty-six young adults with limited chest mobility were selected as participants in this study. TECAR therapy was applied to the participant’s diaphragm for 15[Formula: see text]min. Ultrasound measured each group’s diaphragm movement, and a tape measure was used to measure chest mobility. A paired t-test analyzed each group’s diaphragm movement and chest mobility change, and an independent t-test analyzed the difference in the amount of change between groups. The value was set to 0.05. As a result, after the intervention, diaphragm movement (unit: cm) significantly increased from [Formula: see text] to [Formula: see text] ([Formula: see text]). Upper chest movement (unit: cm) significantly increased from [Formula: see text]-[Formula: see text], middle chest movement (unit: cm) increased from [Formula: see text]-[Formula: see text], and lower chest movement (unit: cm) increased from [Formula: see text]-[Formula: see text] ([Formula: see text]). The results provide innovative clinical evidence that TECAR therapy significantly affected diaphragm movement and chest mobility improvement in young adults with limited chest mobility.