1. Check your daily posture. Do you have the habit of hunching over? Do you sit on the table with only one hand for a long time, or do you often shrug your shoulders? These postures may lead to muscle tension, which in turn leads to the trapezius muscle being large on one side and small on the other.

2. Carry out targeted muscle exercise. For example, try some bilateral stretching exercises to make both trapezius muscles develop in a balanced way. Hold for 5- 12 seconds after stretching, then relax and do 10- 12 groups each time.

3. If the problem persists and even tends to worsen, it is recommended to seek medical advice as soon as possible. It is possible that the muscle is damaged by trauma, and then the trapezius muscle is large and small. It may also be caused by poor posture, such as long-term incorrect sitting and standing posture, or frequent shrugging, which may lead to excessive stress on one trapezius muscle.

The above suggestions are for reference only. If the problem still exists, it is recommended to seek the help of a professional medical or fitness coach.