Written by Jenny Moshak, MS, ATC, LAT, CSCS
The rotator cuff is made up of four muscles (supraspinatus, infraspinatus, subscapularis, teres minor) that cross the shoulder joint (glenolhumeral). These four muscles originate on the shoulder blade (scapula) and insert as a tendon on the upper arm (humerus). As a group, the rotator cuff muscles perform the primary motions of internal and external rotation and assist the shoulder throughout the rest of its range of motion. The shoulder is a ball-and-socket joint. The ball (head of humerus) is twice the size of the shallow socket (glenoid fossa), creating a mobile-but-unstable joint. The rotator cuff plays an intricate roll in the stabilization of the shoulder by working with the labrum (a cartilaginous rim attached to the glenoid fossa that deepens the socket). The rotator cuff helps to hold down the ball portion of the joint in the deepest, widest area of the socket Increased stress is placed on the rotator cuff in overhead-throwing, action-type sports such baseball, football, tennis and volleyball, and in overhead-overuse professions such as construction, hair styling, and painting. Strengthening the rotator cuff muscles can help reduce injury as well as improve performance.
Strengthening exercises for the rotator cuff
Lie face down on a table or corner of a bed. Arms are hanging off the edge of the table. This exercise is broken down into four movements:
- Draw your shoulder blades in to the center of your body (scapular retraction). This will bring your arms slightly off the table.
- Externally rotate your arms—“stick-up” position.
- Extend your arms overhead—officials indicating scored field goal position.
- Hands behind head—“chillin’ position”
- Reverse the four movements back to starting position.
Perform three sets of 10 repetitions.
The only place the arm is actually attached (bones and ligaments) to the body is where the collar bone (clavicle) meets the breast bone (sternum) at the strenoclavicular (SC) joint. The design of the upper extremity allows for its main function, to bring food to the mouth. This main function requires a relationship and coordination between the SC joint, the rotator cuff, and the radial head/thumb.
Tubing with Thumb Involvement
Stand with a rolled towel, foam roller or even a football between your elbow and side of your body. Rest your elbow against the object so that it is in 60 degrees of flexion (in front of your body) and 60 degrees of abduction (away from the side of your body). Attach the tubing to a stationary object so that is it waist height.
- Internal Rotation: Wrap the tubing around your hand and your thumb; make the tubing taut enough so that resistance is present throughout the range of motion. Start with your arm at the end range of external rotation (away from the body) and your hand/thumb in supination (palm up/”hitch hiking”). Pull the tubing in towards your body (internally rotate) and turn your palm downward (pronate) so that your thumb ends up pointing at your stomach. Perform three sets of 10-15 repetitions.
- External Rotation: Wrap the tubing around your hand and your thumb; make the tubing taut enough so that resistance is present throughout the range of motion. Start with your arm at the end range of internal rotation (against your stomach) with your palm facing down (pronation). Pull the tubing away from your body (externally rotate) and turn your palm upward (supination) so that your thumb ends up in the “hitch hiking” position.
Perform three sets of 10-15 repetitions.
Stand holding light-weight plates (2.5-5 lbs.) in the palms of your hands.
- Start with the weights under your chin (as if “smelling” the pizza)
- Keeping the weights at shoulder height, extend your arms in front of your body.
- Maintaining the weights at shoulder height, move your arms out to the side of your body.
- Bring your arms back in front of you. Bring the weights back under your chin (again as if “smelling” the pizza)
You are tracing a “T” in this exercise. Perform three sets of 10-12 repetitions.
Isolating the supraspinatus muscle can be beneficial in rotator cuff strengthening.
Stand holding light dumbbells (3-5 lbs.) at your side.
- Internally rotate your arms so that your thumbs are pointing to the floor.
- Raise your arms at a 45-degree angle (the line between in front of your body and the side of your body) up to shoulder height.
- Lower the weight to the starting position.
Perform three sets of 10 repetitions.
A healthy rotator cuff impacts the function of shoulder movement and stability. Understanding the physical design of the rotator cuff as it relates to body movement is important for maintaining strength, extending performance and preventing injury.
View the full spring 2010 issue of the ACSM Fit Society® Page online.