**2. Materials and Methods**

#### *2.1. Participants*

Sixteen healthy third-trimester primigravid pregnant women (age: 28.4 ± 2.30 years and height: 1.63 ± 0.04 m and trimester: 33.43 ± 3.37 w) participated in the study. Exclusion criteria included the following medical conditions: lupus, rheumatoid arthritis, gestational diabetes mellitus, hypertension, musculoskeletal or neurologic abnormalities, and any other conditions affecting postural stability [5]. All participants understood the purpose and significance of the research and signed an informed consent form. This study with detailed guidelines for participants' safety and experiment protocols was approved by the Human Ethics Committee of Ningbo University.
