Always strive for full range of motion (ROM).

The main reason you may not be able to go full ROM is because you have trained your body to only do half or three-quarters of the movement.

It will normally just be a matter of lowering the weight and taking time to let your body adjust to what is basically a foreign form of training.

Some people are not as flexible as others. Practice STRETCHING to help improve your flexibility and mobility for full ROM.

Related Questions:

1. What are static stretches and dynamic stretches and which is best?