Examples of common positional mistakes - Seat tipping forward
This causes your weight to be over the withers therefore restricting the horse’s ability to lift through them
Your legs tip too far back
Your body becomes inverted therefore blocking the contact elasticity and you do not have contact through your seat.
This then restricts the horse from working with his natural gait and you will find it difficult to maintain a balance.
If you jump like this you will be in front of the movement and therefore it will be easier to be unseated.
To correct this for dressage/flatwork you should sit tall in the centre of the saddle, keep your weight even in your stirrups and relax through your shoulders.
There should be an invisible line from your shoulders through to your hips and heels.
Don’t grip with your knees and keep yourself relaxed in your thigh and through your pelvis