Suwariwaza are seated techniques that are performed with both attacker (uke) and defender (nage) in a kneeling position.
These types of techniques originate in the practice of requiring samurai to sit and move about on their knees while in the presence of a lord.
In theory, this made it more difficult for anyone to attack them. It was also a position in which one received guests (not all were trustworthy).
In Aikido, knee walking is important for learning how to use and strengthen your hips, legs, knees, ankles, and toes. It also helps in developing the flexibility of your muscles, tendons and ligaments.
Shikko is a form of walking on the knees from a seated (seiza) position. It was designed to improve balance, hip stability and prepare a student for the execution of suwariwaza or seated techniques.
Shikko is very important for developing a strong awareness of your centre of gravity. This is helped by focusing your mind on your 'one point' in your lower belly (hara).
Of course, it is more natural for students in the East, as knee walking is more common in their daily life... eating, tea ceremony, etc.
In the West we are taught to sit in chairs and experience life from a more upright position. Even when we pray we are rarely on our knees, because it can be seen as a weak and submissive position. It doesn't fit in with our upbringing where we are taught to be individual, proud, full of self.
In my opinion we should learn to kneel down, bow our heads, be more humble and accept that we are not as important as our inflated ego's would have us believe.
Aikido training is an excellent way of teaching you how to become a warrior. One who is strong and powerful, but also gentle and loving. Seiza, shikko and suwariwaza will all help you achieve it.
Aikido Success Blueprint shows you how to fast-track your skills.
Knee walking puts a lot of pressure on your muscles, tendons, ligaments and joints, and incorrect practise can lead to physical injury.
But you can avoid many of the problems that may come up in your practise, simply by preparing your body in the right way.
Ok, so what can you do?
1 - First of all develop a good level of physically fitness.
2 - Relax your mind/body, and loosen up your joints.
3 - Plenty of practise on stretching and flexibility.
4 - Development of muscle strength, speed, and power.
5 - Learning important nutritional needs and remedies.
When you have taken action on these, then your practise of seiza, shikko, and suwariwaza will be less painful, and become more enjoyable.
All of these points are covered, in detail, in my Aikido First Aid Kit Ebook. Get it absolutely free with my... Aikido Success Blueprint Ebook Collection
A good yoga stretching routine will balance your energy centres (chakras), greatly improve flexibility, and develop all-round strength.
How do I know?
I practise it for 15 minutes every day, and I wouldn't recommend anything that I haven't checked out personally :)