Subcutaneous fat tissue thickness
Obesity has been proposed as a risk factor for low back pain (LBP), and the body mass index (BMI) has been used for obesity; however, a more reliable tool is required to assess obesity-related health issues. A recent study depicted the subcutaneous fat tissue thickness (SFTT) at the L1-L2 level as superior to BMI in predicting LBP and spine degeneration. However, the study failed to answer the following questions: (1) What was the cutoff value for the SFTT to predict LBP and spine degeneration? (2) Could this new index be adjusted according to gender? (3) Could this new index predict fatty infiltration in the paraspinal muscles, severe intervertebral disk degeneration (IVDD), and Modic changes in the lumbar spine? Therefore, the current study aimed to answer these questions by developing and validating a new anthropometric index-the subcutaneous fat index (SFI).