What is the optimal range of motion for shoulder flexion, specifically at 90 degrees, in order to prevent injury and improve overall shoulder function?

The optimal range of motion for shoulder flexion is typically between 150-180 degrees. Maintaining flexibility and strength in this range can help prevent injury and improve overall shoulder function. It is important to be cautious when performing activities at extreme ranges of motion, such as 90 degrees, to avoid straining the shoulder muscles and ligaments.