How can I avoid a repeat rotator cuff injury?

Luck & strength. Rotator cuff injuries become more common as we age for several reasons. The rotator cuff tendon thins as we age and the bony architecture becomes more narrowed. This can lead to impingement and tearing of the rotator cuff tendon. In order to avoid injury, it is important to maintain strenght and flexibility of the shoulder joint. Try to avoid things that aggravate your shoulder.
Be smart & lucky. While there are some variables that you have the ability to control (such as how you lift, what activities you participate in, etc), there are some variables that you cannot easily control. This includes normal aging of the tendon and genetics.

Related Questions

What should you avoid to eat when you have a muscle tear or rotator cuff injury?

Muscle tear. There are no specific studies showing that any one single nutrient would hurt or help for this injury. Maintain a well-balanced diet, making sure that you have adequate protein intake. Read more...
See below. I don't think there is any one food you should avoid as long as it provides nutritional value. Eating foods that are rich in anti-oxidants will be helpful as well as protein, fat and carbohydrates. Read more...

What are foods to avoid eating when you have a muscle tear or rotator cuff injury?

Good Question. I'm not aware of any studies or research looking at relationship of shoulder and rotator cuff symptoms and food. That said, for patients planning on a surgical procedure it does make sense to optimize your nutrition to promote healing. Read more...