A common misconception is that any martial art offers the opportunity to reach an 'internal' level of practice i.e. a karate man can become internal.
This is not true.
Internal forms are quite different to external ones.
They were designed to be a vehicle for the exploration of a very unique way of moving and using the body.
Movement is initiated by the centre (not by the hips) and entails moving every part of the body as one fluid unit. The joints do very little work.
The combat skills and sensibilities of the internal martial arts require a perceptual shift: blending, yielding, listening, stickiness.
There is no blocking, struggling or forcing involved.