Improve Throwing Velocity: Plyometric Training for the Shoulder
So you have spent the off season working hard on endless squats, lunges, and box jumps to improve leg strength for a powerful push off. And you also trained the core with tiring planks, chops, and medicine ball tosses to transfer that power efficiently, but you find that you are still just shy of reaching that ninety mile hour fastball. What else can you train to help put you over the top and achieve that commanding fastball? The next place you should look to train is the shoulder and arm.
Throwing is extremely stressful on the shoulder and elbow joints. Professional baseball pitchers have been measured to reach 7500-7700o/sec of humeral (shoulder) internal rotation velocity during a pitch, and upwards of 2200-2300o/sec of elbow extension velocity. This can produce around 64 Newton-meters of valgus torque at the elbow, which is enough to tear the medial ulnar collateral ligament if the muscles do not provide enough counter-torque. This is why it is important the muscles of the shoulder and elbow are appropriately trained and ready to accept these forces.
Because of the large amounts of motion and power needed to pitch at high speeds, the shoulder needs to be both mobile and stable, which is known as the “thrower’s paradox." Mobility can be achieved through shoulder, elbow, and wrist stretches, but stability needs to come from muscular strength around the shoulder blade. An excellent way to train the shoulder and arm to prepare for the high forces and speeds created while throwing is to perform plyometric exercises.
Plyometric exercises are exercises designed to improve the amount of force a muscle produces in a shorter period of time, which means they are done quickly. A plyometric exercises has three phases. The eccentric loading phase is when an external force is place on a muscle and the muscle-tendon unit lengthens as a result. This is followed by an amortization phase which is the transition time between when a muscle produces enough force to stop lengthening and begins to start shortening, and the joint angle motion will change direction. The last phase is a quick concentric contraction phase where the muscle shortens and produces force to create a quick movement.
For those who want to know a little more how plyometric exercises can change the neurophysiologic properties of muscles, there are two nerve receptors that measure muscle properties. Muscle spindles are located around the muscle fibers. They detect the stretch of the muscle and elicit a muscle contraction in that same muscle as a protective mechanism so it is not overstretched. The strength of this contraction depends on the rate of muscle stretch. So by stretching a muscle in the eccentric loading phase, we can allow the muscle to provide a stronger than normal muscle contraction. This is called the myotatic stretch reflex. The other receptor is the Golgi tendon receptor which is located at the musculotendinous junction. Normally this receptor detects the force of muscle contraction and inhibits the agonist muscles and activates the antagonist muscles as a protective mechanism. However, recent data suggests the Golgi tendon organ can actually initiate excitatory reflexes during locomotion and plyometric activities resulting in an increase in muscle contraction. Utilizing these reflexes during training allows muscles to generate more force than voluntary contractions, and through specificity of training, these reflexes become faster.
The goal of plyometric exercises is to decrease the time of the amortization phase so that maximal force is created in the shortest amount of time. This is the definition of power: larger forces in shorter periods of time. Since pitching is dependent on how much force can be placed on the ball and is time dependent, pitchers should be utilizing plyometric exercises.
Compared to the lower extremity, the efficacy of plyometric exercises in the upper extremity have not been well documented. Because of the lack of research, there are no validated guidelines on which sport athletes benefit most from plyometric training. However, an article by Andrew Carter found a 2 MPH increase in throwing velocity for college baseball players who performed eight weeks of training using the Ballistic Six throwing program, suggesting baseball pitchers will benefit since they are performing a powerful movement when throwing. The American College of Sports Medicine recommends for power training performing 3-5 sets of 1-5 reps at a load 30-60% of the one rep max. Rest time should be 3-5 minutes between sets and done training should be done 3-5x/week.
Examples of upper extremity plyometric exercises include weighted ball IR/ER tosses, medicine ball wall toss, medicine ball slams, and plyometric push-ups. If you are interested in learning more about how plyometric exercises can help you reach the next level in your training and pitching, email, call, or visit our clinic in San Jose, CA.
Written by Matt Rickerts, PT, DPT
Competitive EDGE Physical Therapy
Serving Bay Area residents