Traditional Tai Chi is not about achieving skill by simply being "relaxed" but rather about using the right force (Li), applying Li correctly, and engaging in proper expansion and contraction movements. The "square frame" utilizes a balanced and stable "internal Li (force)" to support and stretch the entire spine, joints, tendons, and muscles, promoting expansive and gentle large opening and large closing movements, as well as calm, balanced lifting and sinking. These movements gradually improve the body's functions and quality, increasing its strength and flexibility. One should coordinate the internal and external movements, maintaining a balance between tension and relaxation, connecting each section, and integrating it into the spine, allowing the "centralized internal strength (Zhong Ding Nei Jin)" to govern the whole body, resulting in an "elastic" body frame that can withstand pressure without collapsing even during dynamic movements.