The sit-up itself is through the back and forth up and down movement, to exercise the abdomen, so this equipment helps to help the abdominal muscles in the human body exercise, to allow exercisers to better control their own body, and here belongs to the middle of the body, for the human body is also a certain role, to strengthen the support for the back. Helps to better engage in other sports.
https://www.yaconfitness.cn/product/adjustable-sit-up-bench/