Throwing Velocity: Transferring Power through the Trunk
We hear so much about the importance of “core strength” that it is put into almost every sports training program. However, much less often do athletes know what the “core” consists of or why it’s important. And it becomes even more confusing trying to find the “best” or most appropriate core exercises due to the sheer volume of articles dedicated to the subject that can be found online or in fitness magazines.
These fitness articles and magazines almost always show a guy or gal with six pack abs and a catchy title of “top 5 exercises to blast your abs for that great summer look!” This only perpetuates the misconception that you need a six pack in order to be athletic and have a strong core, but the cores is so much more than having an impressive rectus abdominis.
The core or trunk is all of the muscles that connect the lower limbs to the axial skeleton or provide movement or stability at the axial skeleton: vertebra, pelvis, or ribs. These muscles include the abdominal muscles (rectus abdominis, transvers abdominis, external/internal obliques, and diaphragm), the back muscles (erector spinae, paraspinals, multifidus, rotatores, latissimus dorsi, and quadratus lumborum), and hip muscles (gluteus maximus/medius, hamstrings, iliopsoas, and adductors).
If we look at baseball pitchers, the function of the core is to transfer the power that is generated from the legs during the pitching stride (see previous blog) through the trunk and into the shoulder and arm. If the transfer occurs efficiently, less power is lost and the arm can supply more force into the ball leading to faster pitching velocities. If the transfer is inefficient, power is lost and ball velocity declines.
So what determines whether the transfer is efficient or inefficient? Power must be transferred from movement at one joint into movement at the next joint through the use of muscles. Depending on the joint, these movements may need to be linear, rotational, or most often a combination of both. If the muscles crossing the joints are not strong enough or ready to provide tension through a timely contraction, then the muscle fibers can lengthen rather than shorten and power is lost into creating a movement in the wrong direction. Thus, an efficient transfer of power is due to a strong and timely contraction
of muscles to provide torque at joints and movement in the correct direction. We call inefficient movements “power leaks”. Power leaks where force is lost due to movement in another direction can be caused by a lack of motion at the joint or muscles not able to provide tension to prevent motion in the wrong direction. This is why it is important to look at pitching mechanics and correct power leaks when improving throwing performance.
Thinking back to your childhood, a good example that demonstrates this concept of efficient or inefficient power transfer is jumping on a trampoline. When you jump on a trampoline, the weight of your body on the mat stretches the springs which then shorten and can provide an upward force to propel you to a higher than normal jump. And you may have experience getting bounced higher when jumping with a friend, if they time their jump to help you stretch the springs at the same time. However, if they jumped too early and pre-stretched the springs, or too late and stopped the springs from shortening, you lost the force to propel you up and your jump height was decreased.
Physical therapists are movement experts trained to identify power leaks, inefficient movements, or movements creating abnormal forces and placing individuals at risk of injury. We can test muscle strength, muscle length, and joint mobility to determine the weak link in the kinetic chain and how to train through exercises to improve efficiency of movement and performance. There is a principle in performance training known as “specificity”. It states that in order to improve your performance, your training and exercises must be relevant and appropriate to the task you need to perform.
For baseball pitchers, their motion requires a very rapid transfer in power from the legs to the arm. The legs generate the power from hip extension, knee extension, and ankle plantarflexion, which continues through rotational force in the trunk and into the shoulder and arm. Rotational strength through the trunk is extremely important for baseball pitchers because if they open up their trunk too early they lose torque/power, and if they don’t rotate enough they lose torque/power. Thus, pitchers should spend a majority of their “core” workout performing rotational exercises.
Functional core exercises for baseball pitchers include working the external/internal obliques, multifidus and rotatores muscles, gluteus maximus/medius muscles, rectus abdominis, and performing plyometric activities to ensure specificity of training for speed and timing. Exercises such as: pulley chops/diagonals, swiss ball walkouts with hip extensions, Russian twists, rotating side/front planks, multifidus walkouts, plyometric jumps, and medicine ball toss are all excellent exercise to improve core strength for baseball pitchers.
If you are interested in learning more about pitching mechanics, strength training, and improving overall performance, take the next step in reaching your goals by emailing, calling, or visiting our clinic in San Jose, CA.
This blog was written and researched by a previous Competitive EDGE Physical Therapy employee.