Knowing Your Shoulder Joint
Your shoulder is a complex joint made up of three bones: the humerus or upper arm bone, the clavicle or collar bone and the scapula or shoulder blade. Your shoulder is a ball and socket joint with the head of your humerus fitting into a socket at the end of your scapula. The four rotator cuff muscles -- the supraspinatus, infraspinatus, subscapularis and teres minor -- form a covering over the head of your humerus, keeping your upper arm secure in your shoulder socket.
Rotator Cuff Injuries
According to the American Academy of Orthopaedic Surgeons, the two main causes of rotator cuff tears are injury and degeneration. An injury may be caused by falling on your outstretched arm, lifting a heavy object with a jerking motion, breaking your clavicle or dislocating your shoulder. Degenerative tears are caused by repetitive stress, such as repeating the same shoulder motion when weightlifting.
Deadlifts and Your Rotator Cuffs
When performing deadlifts, your rotator cuffs work intensely to stabilize your scapula and keep your upper arm secure in your shoulder socket. Writing for Functional Movement Systems, strength coach Gray Cook emphasizes you shouldn't shrug your shoulders or retract your scapula as you lift the bar from the floor. This places extra stress on your rotator cuffs. Using a light weight makes it more likely that you shrug your shoulders and retract your scapula. It is much harder to shrug your shoulders and retract your shoulder blades with a heavy weight. Tense your shoulders to enhance joint stability and reduce the workload on your rotator cuffs. However, don't use an excessively heavy weight that compromises your technique and increases risk of injury. Ensure you can perform a proper hip-hinge, keep your back straight, and your chest up.
The deadlift simultaneously engages several joints and muscles. It is an intense exercise that is demanding on your musculoskeletal structure even when performed with correct technique. Though deadlifts are not inherently bad for your rotator cuffs, you shouldn't perform the exercise more than twice a week, with at least two days of rest between workouts to ensure adequate recovery. If you use very heavy weights, do deadlifts only once a week.
Exercises To Avoid
Wide-grip bench presses place excessive stress on your rotator cuffs. According to the "American Journal of Sports Medicine," you should use a grip that is no more than 1.5 times your biacromial width. This is a slightly wider than shoulder-width grip with your forearms roughly parallel to each other. The biacromial width is the distance between the two bony protrusions at the top of each shoulder. Avoid the barbell press-behind-neck and lat pulldowns behind the head. The AJSM says these exercises cause excessive external rotation of your shoulder joints and may hurt your rotator cuffs.