I do these while playing with the kids on the floor or
watching a movie with the family.
Sit fully upright on a chair with feet flat on the floor slightly apart.
Place your fingertips so they are touching the top of the shoulders, so the arms are bent at the elbows.
Slowly twist the elbows, arms and shoulders as if you are turning to look over your shoulder. Don't turn your head, let it follow round with the upper part of your body.
Throughout the turn keep your abdominal muscles tensed.
Once you have reached as far round as is comfortable, slowly rotate back round to the opposite side, then return to the starting position.
Repeat the exercise for a further 5-6 repetitions.