In Rinzai Zen, koan practice is a central and highly emphasized form of meditation. However, it is not the only form of meditation in this tradition. Rinzai Zen also incorporates other practices such as seated meditation (zazen), chanting, and physical exercises.

Koan practice involves the use of paradoxical questions or statements, known as koans, to challenge the student's logical thinking and push them towards a state of sudden awakening or enlightenment. These koans are often nonsensical or seemingly impossible to solve, and the purpose is to break through the limitations of the rational mind and reach a deeper understanding of reality.

While koan practice is the primary focus of Rinzai Zen, it is often accompanied by zazen, or seated meditation. In zazen, practitioners sit in a specific posture and focus on their breath or a specific object, such as a wall or a candle flame. This practice helps to cultivate mindfulness and concentration, which are essential for understanding and resolving koans.

Chanting is also a common practice in Rinzai Zen, with the recitation of sutras and mantras being an integral part of the daily routine in monasteries and temples. Chanting is believed to have a purifying effect on the mind and can help to deepen one's understanding of Buddhist teachings.

Physical exercises, such as martial arts or calligraphy, are also incorporated into Rinzai Zen practice. These activities require intense focus and can help to develop discipline and concentration, which are crucial for koan practice.

It is important to note that in Rinzai Zen, all of these practices are seen as tools for reaching sudden awakening, rather than separate techniques. They are all interconnected and work together to help practitioners let go of their attachments and reach a state of enlightenment.

In conclusion, while koan practice is the primary form of meditation in Rinzai Zen, it is not the only practice. Other forms of meditation, chanting, and physical exercises are also essential components of this tradition, all working towards the ultimate goal of sudden awakening.