Wu Song does not explicitly mention in the story of Jingyanggang fighting the tiger that he used Taijiquan. So, here are some speculations that can link Wu Song's fight against the tiger to tai chi:
Use of internal force: Taijiquan focuses on the use of internal force, and Wu Song successfully defeated a strong opponent through his inner strength and determination when he fought the tiger.
Overcoming rigidity with softness: Taijiquan emphasizes overcoming rigidity with softness, and defeating opponents through skillful techniques and postures. Wu Song may have used a similar strategy in the fight against the tigers.
Flexibility: Tai Chi's posture requires flexibility and the ability to respond to a variety of attacks. Wu Song showed excellent physical skills and dodging ability when fighting tigers.
Follow the trend: Tai Chi pays attention to following the trend and following the opponent's movements to defuse the attack. Wu Song may have used a similar principle when fighting the tiger, following the tiger's attack to fight back.
Borrowing Force: The technique of borrowing strength in Tai Chi can help Wu Song use the strength of his opponent in battle. Wu Song may have used a similar technique when fighting the tiger, using the power of the tiger to enhance his attacks.
Mental Concentration: Tai Chi emphasizes mental concentration and mind guides movements. Wu Song was highly focused on fighting the tiger and was fully engaged in dealing with the challenge.
Breathing coordination: Tai Chi focuses on the coordination of breathing, and regulates the state and strength of the body through breathing. Wu Song may have used a similar breathing technique to build his strength and endurance when fighting tigers.
Varied moves: Tai Chi moves are varied and creative, and can be used flexibly according to different situations. Wu Song displayed a variety of moves and techniques when fighting tigers, echoing the diversity of Taijiquan.
Sense of Rhythm: Tai Chi focuses on a sense of rhythm and controls the rhythm and progress of the battle by mastering the rhythm. Wu Song may have used a similar sense of rhythm to control the battle when fighting the Tigers.
Moral cultivation: Tai Chi is not only a martial arts technique, but also emphasizes moral cultivation and spiritual improvement. As a heroic and upright figure, Wu Song's moral and moral concepts are in line with the self-cultivation concept of Taijiquan.
Please note that the above is only speculation, and there is no conclusive evidence that Wu Song's fist method of beating the tiger is Taijiquan.