The unique demand of throwing a baseball places a great deal of stress on the bones, muscles, and soft tissues of the arm. Therefore, shoulder and elbow injuries are common amongst baseball players of all ages. Repetitive throwing leads to adaptations in the bony structure and muscles around the shoulder. Some of these adaptations are believed to be necessary in order to perform at a high level. Other changes, specifically those related to muscle tightness, can increase the risk of sustaining an elbow or shoulder injury. Therefore, it is important for baseball players, coaches, and parents to understand the rationale and best methods for stretching the muscles of the arm in overhead athletes.
Range of Motion in the Baseball Pitcher
The amount of shoulder external and internal rotation range of motion receives a great deal of attention in overhead athletes. Repetitive throwing during a youth athlete’s period of peak growth induces adaptive changes to the structure of the upper arm bone. The middle portion of the arm bone actually rotates backward in relation to the upper end of the bone or head of the humerus. This is termed retroversion and it is believed to be a necessary and beneficial adaptation. Retroversion of the humerus allows the baseball player to achieve greater amounts of shoulder external rotation, or layback, during the arm cocking phase of throwing.
Retroversion of the humerus will cause an increase in the amount of shoulder external rotation but a decrease in the amount of available internal rotation. Again, this is believed to be a necessary adaption to improve performance. Research suggests that the total arc of internal and external rotation range of motion is what becomes important. The total arc of motion between the throwing and non-throwing shoulder should be within 5 degrees of each other (shown in the illustration below). When greater discrepancies in the total arc of motion are present, stretching exercises should be performed to improve symmetry between sides.
The Basics of Stretching for Baseball Players
Baseball players have been shown to lose range of motion throughout the course of a single game and over the course of a season. This loss of range of motion and flexibility typically occurs in the shoulder and elbow musculature. Common muscles prone to tightness in baseball players include the rotator cuff, lattisimus dorsi, pectoralis major and minor, biceps, and triceps. A regular stretching routine, performed 3-5 times per week, can help restore lost range of motion. Also, a basic 10-minute stretching routine may potentially improve performance and decrease risk for an arm injury. The stretching exercises presented here are a few baseball players should be familiar with.
Five Arm Stretching Exercises for Baseball Players
- Cross-Body Stretch: This stretch addresses the posterior shoulder muscles which are prone tightness in overhead athletes. The infraspinatus, teres major, and teres minor muscles can become shortened from repetitive throwing. This stretch is performed lying on the involved side with hips and knees bent. The involved shoulder and elbow are positioned in 90 degrees of flexion. The hand of the uninvolved arm grasps the elbow of the involved arm and gently pulls it across the body. Once a mild stretch is felt on the outside or back of the shoulder, this position is held for approximately 30 seconds. The stretch is typically performed 2-3 times each session.
- Sleeper Stretch: The cross-body stretch has been shown to be superior to the sleeper stretch for improving shoulder range of motion in young baseball players. However, the sleeper stretch is probably the more popular of the two stretches. For this stretch, the same starting position as the cross body stretch is assumed. However, with the sleeper stretch, the wrist and forearm of the involved arm are gently moved down towards the table. Once a mild stretch is felt on the outside or back of the shoulder, this position is held for approximately 30 seconds. The stretch is typically performed 2-3 times each session. For most athletes, both the sleeper and cross-body stretch do not need to be performed. My personal experience, and the best available evidence, suggests the cross-body stretch is the most beneficial for improving range of motion.
- Bench T-Spine Mobilization: Extension of the upper back is necessary to achieve the arm cocking position needed for throwing. Without adequate extension of the spine, unnecessary stress will be placed on the shoulder or elbow. This stretch also provides a nice stretch to the lattisimus dorsi and triceps muscles which can also limit overhead mobility. The exercise begins by assuming a kneeling position facing a bench. Place your elbows on the bench in front of you holding a PVC pipe or dowel with the palms facing up. Sit back, pushing your buttocks towards your heels, keeping your spine relaxed, until you feel a stretch in your upper back. Be sure to engage your abdominal muscles to prevent excessive arching of the low back. (I could have done a better job of this in the video below). For an added stretch you can bend your elbows further past your head. Hold this position briefly, and exhale fully. Reverse the motion to return to the start and repeat 6-8 repetitins.
- Thoracic Spine Windmill: This is a great dynamic mobility drill to restore thoracic spine rotation and improve the flexibility of the lattisimus and pectoral muscles. Begin on your side with both arms outstretched in front of you. Place a foam roll under your top leg with the knee and hip bent to 90 degrees. The bottom knee and hip remain extended throughout the exercise. Reach forward with your top hand and then complete a large circular windmill motion as you rotate your entire upper body. Keep reaching as if you were attempting to lengthen your entire arm. Follow your hand with your eyes to ensure proper thoracic spine and rib cage movement. The top knee and leg should remain in contact with the foam roll throughout the exercise. We generally perform 6-8 repetitions on each side.
- Side-Lying IR/ER: This is a more advanced dynamic mobility exercise targeting the thoracic spine, rib cage, lattisimus dorsi, and pectoral muscles. Start in a side-lying position with the arm to be stretched on top. Place a foam roll under your top leg with the knee and hip bent to 90 degrees. The bottom knee and hip remain extended throughout the exercise. Initiate the movement by reaching with the lower arm up towards the sky. Hold this position, reaching upwards, throughout the drill. The arm to be stretched is then placed overhead with the thumb pointing down towards the floor. Exhale fully at the top and then reverse the movement by bringing the arm down to the side. As the arm is lowered the thumb position changes so it is pointing down towards the back pocket. It is important that both elbows remain fully straight during the drill. We generally perform 6-8 repetitions on each side.
These five stretching and mobility drills address typical muscle flexibility problems baseball players present with. As always, an individualized approach is always superior to ready-made one-size fits all programs. Building arm strength through resistance training is also important for improved performance and resiliency in the baseball player. Before engaging in any exercise program, those with a history of arm problems or those currently experiencing pain should first be evaluated by a physician, physical therapist, or athletic trainer. Some players may require additional arm care strategies such as passive stretching and soft tissue mobilization techniques.
- Bailey LB, Thigpen CA, Hawkins RJ, Beattie PF, Shanley E. Effectiveness of manual therapy and stretching for baseball players with shoulder range of motion deficits. Sport Heal A Multidiscip Approach. 2017;9(3):230-237. doi:10.1177/1941738117702835.
- Hibberd EE, Oyama S, Myers JB. Increase in humeral retrotorsion accounts for age-related increase in glenohumeral internal rotation deficit in youth and adolescent baseball players. Am J Sports Med. 2014;42(4):851-858. doi:10.1177/0363546513519325.
- Keller RA, De Giacomo AF, Neumann JA, Limpisvasti O, Tibone JE. Glenohumeral internal rotation deficit and risk of upper extremity injury in overhead athletes: A meta-analysis and systematic review. Sport Heal A Multidiscip Approach. 2018;Online:1-8. doi:10.1177/1941738118756577.
- Mine K, Nakayama T, Milanese S, Grimmer K. Effectiveness of stretching on posterior shoulder tightness and glenohumeral internal-rotation deficit: A systematic review of randomized controlled trials. J Sport Rehabil. 2017;26:294-305.