It's estimated that there are over 6 million youth and adolescent baseball players in the United States. Studies of American youth and high school baseball players have found an incidence of elbow pain of 26% among youth players and 58% among high school players. The incidence of shoulder pain was found to be 29% to 35%. This represents a significant number of shoulder and elbow throwing injuries. These injuries are on the rise in the U.S. and Dr. James Andrews has described this as an epidemic. He reported an alarming sequential increase in the number of Ulnar Collateral Ligament reconstructions (Tommy John surgery) in high school versus college or professional pitchers over three consecutive four-year periods.
Percent of High School Pitchers undergoing Tommy John Surgery:
The increasing rate of shoulder and elbow injuries is related to how much athletes are throwing. USA Baseball and Little League Baseball now have rules designed to help protect athletes from these injuries. Adhering to these pitch counts is a priority in avoiding injury. For those playing on more than one team, the pitch counts are the total for all teams.
Little League Baseball has the following pitch count regulations:
Age Pitch Count
10 or less 75
USA Baseball has different pitch count limits:
Age Pitch Count
Dr. Khalfayan’s Tip: Here in the Seattle area, my recommendation is to follow the most conservative recommendation for each age group and follow the USA Baseball pitch count limits. They can be modified lower on an individual basis as needed.
Risk Factors for throwing injuries
Most throwing injuries are due to overuse. Studies have shown the following factors are associated with shoulder and elbow injuries:
1. Pitching with fatigue
Pitching with arm fatigue increases the risk of injury 36-fold - this is a 3,600 percent increase in risk of injury!
2. Pitching more than 8 months per year
Adolescent pitchers who pitched more than 8 months per year were found to have a 5-fold increase in injury risk. Researchers found pitchers who required surgery pitched an average of 8 months per year compared to 5.5 months per year for those who did not require surgery.
3. Pitching more than 100 innings per year
In a prospective study of 481 pitchers aged 9-14, it was found that pitchers who pitched more than 100 innings in a year had a 3.5-fold increase in injuries.
4. Pitching more than 80 pitches per game
Pitchers 14-20 years old who threw more than 80 pitches per game were found to have a 4-fold increased risk of needing surgery than those who threw less than 80 pitches per game.
5. Pitching in showcases
Injured pitchers pitched in 4 showcases per year compared to 1 showcase for uninjured pitchers.
6. Pitching with high velocity
Pitchers 14-20 years old who threw with a velocity of greater than 85 mph were 2.6 times more likely to have an injury requiring surgery.
7. Using anti-inflammatory medication
Pitchers who used anti-inflammatory medications and iced their arms were more likely to have shoulder and elbow injuries. Pitching with pain is associated with an increased injury risk.
8. Playing pitcher and catcher
Research has shown a trend for pitchers who also play catcher to more likely be injured.
9. Starting pitchers, tall or heavy pitchers
Pitchers falling into these groups have been found to have a tendency for more injuries. This may be due to these pitchers typically throwing with greater velocity.
10. Throwing more warm-up pitches
Pitchers who throw more warm-up pitches (average 34) were found to have a higher injury rate than a control group (average 28) of adolescent pitchers.
The above are not the only factors involved in shoulder and elbow throwing injuries. Other factors include pitch type, pitching mechanics, strength, and flexibility.
Pitch Type and risk of arm injury
It has long been felt that throwing breaking balls places greater stress on the elbow and shoulder. The standard recommendation has been that pitchers should not throw curveballs before the age of 13.
Older studies have shown higher rates of arm injuries with throwing breaking balls compared to fastballs and change ups. A study in 2002 found an association between throwing a slider and elbow pain and throwing a curveball and shoulder pain.
However, more recent studies have shown higher stresses on the elbow and shoulder with throwing a fastball compared to a curveball. Throwing a change up had the least amount of stress.
At this time, there is not conclusive evidence that throwing breaking balls leads to an increased rate of shoulder or elbow injuries. The change up has the least stress on the throwing arm and is the safest pitch to throw.
Dr. Khalfayan’s Tip: The science behind baseball injuries is not developed enough for us to definitively say which pitch types are higher risk and when they should be introduced. Along with the science, recommendations from those coaches and physicians with experience should be considered. In general, they lean toward avoiding throwing breaking balls before the age of 13 or 14. I recommend following this rule until the science is clearer. The most important risk factors are throwing with pain or fatigue and throwing too much.
Pitching mechanics is a complex and controversial subject. This discussion deals with mechanics from an injury viewpoint and is not meant to replace coaching. The biomechanics of pitching have been studied and found to play an important role in both performance and injury. Energy required to throw a baseball is transferred from the lower extremities through the trunk/core into the arm-the body’s kinetic chain. This requires strength in the lower extremities, pelvis, and trunk to provide a sound base as well as a coordinated sequence of complex movements appropriately timed. If there is a deficit in strength, sequence, or timing, not only will velocity and accuracy suffer, but there will be increased torque and stress placed on the shoulder and elbow, which can lead to injury. Studies have looked at pitching biomechanics and evaluated how efficiency in transferring kinetic energy from the lower extremities to the arm can improve velocity, accuracy, and probably decrease injury. Below is a summary of some of the findings from this work.
Recommendations to improve pitching mechanics:
- Develop good core, trunk rotation, and gluteal strength
- Shorten the interval of stride foot contact to hip rotation
- Land with stride foot pointing toward home plate
- Lead with the hips and rotate them toward home plate (closed hip positioning)
- Point lead shoulder toward home plate at stride foot contact (closed shoulder positioning)
- Keep hand on top of ball as it comes out of glove in early cocking phase
- Get maximal elbow height by stride foot contact
Stretching and Strengthening
Proper warm up is important in any sport. For pitchers it includes not only throwing warm up pitches, but also increasing heart rate and body temperature with some aerobic exercise.
There are adaptive changes that occur in the bone and soft tissues of pitchers shoulders and elbows. The shoulder in youth pitchers has open growth plates that are subjected to rotational forces that can result in a change in the normal relationship of the humeral head (top of the humerus at the shoulder joint) to the rest of the humerus. The joint capsule (lining tissue that forms the envelope of the joint) may contract in the back and stretch out in the front of the shoulder. These changes may result in a loss of internal rotation and increase in external rotation. Some degree of these adaptive changes is very common in pitchers shoulders. When they are excessive, they may lead to injury.
Glenohumeral Internal Rotation Deficit or GIRD is defined as a greater than 20-degree loss of shoulder internal rotation compared to the nonthrowing shoulder. GIRD has been associated with an increase in shoulder and elbow injuries. Stretching the capsule in the back of the shoulder by doing sleeper stretches can reverse GIRD and help prevent these injuries.
Strengthening is helpful for performance and also to prevent throwing injuries. Studies have shown that there is an association between rotator cuff weakness and throwing injuries requiring surgery in professional baseball players and throwing related pain in adolescents. There is a tendency for the rotator cuff muscles in the front of the shoulder to be stronger than those on top and in back of the shoulder. This imbalance may lead to increased stresses on the muscles and joint capsule in back as well as the scapula. The Thrower’s Ten Program is an exercise program developed to help strengthen the muscles in the back of the shoulder and maintain a more normal balance of shoulder strength. These exercises should be done on a regular basis to avoid injury and improve performance.
Youth throwing injuries are on the rise. There are many factors involved in this. Some can be modified. Parents and coaches can play a major role in reducing and preventing these injuries.
Action plan for parents and coaches:
- Educate young pitchers about the warning signs of elbow and shoulder injuries and remove them from play when they have pain or fatigue
- Take 4 months off from throwing each year
- Monitor pitch counts and warm-up pitches
- Limit pitching to 8 months and 100 innings per year
- Develop proper pitching mechanics
- Develop a core, lower body, and shoulder/elbow strengthening program
- Stretch and warm up properly prior to throwing
- Don’t use medication to manage pain with pitching
- Avoid pitching on more than one team and in too many showcases