Baseball Fact or Fiction: Part I

Have you ever wondered why most baseball players put a weight on their bat when they’re in the on-deck circle, or why Coors Field in Denver, CO is such a hitters haven?  Maybe you’ve seen a post game press conference and the pitcher has his entire arm wrapped in ice packs with large ace bandages and thought, “Why does he do that?”  Well, wonder no more, curious baseball fan.  Let’s take some time to look into some of the unique aspects of baseball and answer these questions for you.  This is part I of my “Fact or Fiction” series.  If you have questions you’d like answered, please submit them to the Maniac Ball team on Twitter @ManiacBall.


I.  Hitters warm up a weighted bat on-deck because it makes their regular bat feel lighter and they can swing faster.

Mike Trout waiting on deck.

Mike Trout warming up with a weight on his bat.


This practice goes way back in the sport, and continues still today.  The concept is that the difference in weight will make the regular swing faster, resulting in more power or helping a hitter catch up to a hard thrower.  In reality, swinging a weighted bat actually is counterproductive or inconsequential.  One clinical study demonstrated that not only does warming up with a heavy bat not make the swing faster, it actually hinders a batter’s ability to adjust to a timing exercise (ie. making contact with a ball that is delivered at an unknown velocity).  Montoya, Brian S., et al, at Cal State Fullerton published research in the Journal of Strength & Conditioning in August of 2009 that showed that warming up with a heavy bat decreased the post-warmup velocity of the normal bat swing.  In each trial, subjects would warmup with one of three bats (light bat, normal bat, and heavy bat).  Post warmup normal bat velocity was measured.  Light bat warmup resulted in an average normal bat velocity of 52.29 (+/- 2.68mph).  Normal bat warmup resulted in an average normal bat velocity of 50.60 (+/- 3.04mph).  Both of these conditions, statistically speaking, were significantly faster than the normal bat velocity following the heavy bat warmup, which was 48.26 (+/- 2.98mph).  The difference between the light bat and normal bat warmup was not statistically significant, and thus, their conclusion was that warming up with either of those provided an advantage over the heavy bat warmup.  Other studies that demonstrated the same were published by DeRenne, et al., 1992; Otsuji, et al., 2002; and Southard & Groomer, 2003.

The studies above investigated pure swing velocity.  In a dynamic study, Nakamoto, Ishii, Ikudome, & Ohta (2012) found that warming up with a weighted bat resulted in a relatively large timing error in the cases of a decrease in the target velocity.  In other words, when the pitch came in slower, the timing mechanism was adversely affected.  There are studies that suggest an imbalance between what the athlete feels and what actually occurs results in decreased perceptual motor control (Gray, 2002 ; Gray, 2009 ; Scott & Gray, 2010).  Additionally, Nakamoto, et al., (2012) found that warming up with a weighted bat for an interceptive task, or making contact with a moving baseball, affects the central nervous system rather than the peripheral nervous system.  If we recall our basic human physiology, the CNS is controlled by our brains.  Signals relayed from our eyes or limbs, or any other sensory mechanism for example, must be sent to the brain via the afferent nerves.  The messages are interpreted and relayed back to our bodies through the efferent nerves, also called motor nerves.  The motor nerves control our muscles, and the motor nerves are controlled by the central nervous system.  Remember, this all happens at ridiculously fast speeds, but then again, baseballs are also pitched at very high speeds and a hitter’s reaction time is only a fraction of a second.  Any delay or interruption in the normal processing of the nervous system may interfere with the timing task of hitting a thrown baseball.

Ohta, Ishii, Ikudome and Nakamoto (2014) found that a weighted bat warmup, while having no significant effect on muscle activity before impact associated with temporal or spatial movement corrections, found that the extensor carpi ulnaris was inhibited.  This is a muscle that performs extension of the pinky finger and also performs ulnar deviation, which is when the wrist moves in the direction of the pinky side of the hand.  If you know hitting, you know that the batter needs to “throw” their hands to the ball during their swing.  Ulnar deviation is this particular movement.  Think, holding the bat out in front of you with both hands, and without moving your shoulders or elbows, chopping downward with the bat.  This movement is particularly important in the swing.  Inhibiting this muscle’s activity led the authors to hypothesize that the weighted bat warmup decreased the adjustment ability of the hitter to a moving target.

Not everybody uses weighted bats, but good luck changing the habits of those that do.  If there’s one thing I know about ballplayers, is that these are men of routine.  Sometimes, changing the routine can be more catastrophic than beneficial!


II.  Balls fly out of Coors Field because of “thin air.”

DENVER, CO - JULY 20:  Carlos Gonzalez #5 of the Colorado Rockies hits a solo home run during the fifth inning as catcher Welington Castillo #53 of the Chicago Cubs looks on at Coors Field on July 20, 2013 in Denver, Colorado.  (Photo by Justin Edmonds/Getty Images)

DENVER, CO – JULY 20: Carlos Gonzalez #5 of the Colorado Rockies hits a solo home run during the fifth inning as catcher Welington Castillo #53 of the Chicago Cubs looks on at Coors Field on July 20, 2013 in Denver, Colorado. (Photo by Justin Edmonds/Getty Images)


This is true.  “Thin air” is a lay term for air that is less dense.  At higher altitudes, barometric pressure is decreased, resulting in decreased density.  The same principle applies to temperature.  In fact, the more humid the temperature, more nitrogen and oxygen molecules are replaced by water molecules, resulting in less dense air.  You know how it can feel tough to breathe on really humid days or at altitude?  That is probably why.  This has nothing to do with all the fat NFL lineman you see sucking pure O2 on the sidelines in Denver.  We’ll table that for another day.  Back to the thin air, though.  When the atmosphere is less dense, there is less resistance a projectile has to fight during its flight path.  Sure, there are numerous other factors that affect a batted baseball’s trajectory like type of spin, initial horizontal velocity and initial projection angle.  But all things being equal, the baseball will travel through the air with more ease in a higher altitude stadium.

The viscosity, or thickness, of the air applies to pitchers as well.  A flame thrower would prefer the thinner air of Denver because of the decreased density in the air.  Maybe he can gain a mph or two on his four-seamer.  Alternately, a knuckleballer would prefer a humid night in San Diego.  More viscous air results in more resistance, adding the effect of the knuckleball.  Obviously, the pitcher also prefers the thicker air adding to the difficulty of hitting a homerun against him.


III.  Pitchers ice their shoulders and elbows after their outing to enhance their recovery time and to decrease inflammation.

Mark Mulder icing his left shoulder and elbow.

Mark Mulder icing his left shoulder and elbow.

FICTION (or at least, not a fact)

This one is a bit tricky.  As a certified athletic trainer who spent 9 seasons in professional baseball, I’ve iced down shoulders and elbows thousands of times.  The old adage goes R.I.C.E. (Rest, Ice, Compression, Elevation).  This is how we treat acute injuries, right?  Got a bruise?  Ice it.  Sore knees?  Ice ’em down.  Just pitched 9 shutty on 110 pitches?  You had better be icing that wing!  In my personal experience, icing is a preference.  Most athletes aren’t doing literature reviews on the topic, so they do it for one of a handful of reasons.  Either it’s just part of their post game routine (a mental reason), or their dad told them to do it all through their development.  Maybe they do it just because if they don’t, they maybe aren’t doing all that they can to take care of themselves.  Sometimes it’s advocated by their athletic trainer, their coaches, or a teammate.

Recently, the debate over ice in the athletic training community has been heating up (pun intended).  In my own practice, I’ve never demanded that any pitcher ice down his arm.  I’ve also never refused to provide it when requested.  Every season I would meet with my pitching staffs and tell them this as part of my season opening spiel.  If a player ever asked me what he should do for his arm, we would sit down and have a bit of a longer discussion.  My goal was always to provide them with the means to make their own informed decision.

The research is lacking a conclusive stance on the topic.  In many cases, clinical results will either be statistically insignificant or no changes will occur.  Cryotherapy does provide a temporary pain relieving effect, which can be beneficial in certain situations.  If we’re examining muscle soreness and recovery, there are a few things to consider.  Soreness can be the result of an increase in lactic acid, one of the byproducts of glycolysis (the breakdown of carbohydrates into energy).  It can also be the result of microscopic muscle tears, which will trigger an inflammatory response.  Soreness can occur in our joints as well as our skeletal muscles.  For athletes, they are typically dealing with all of these concurrently.  We’re used to seeing pitchers run sprints in the outfield following a Spring Training outing.  This is part of their regular conditioning and part recovery effort.  They do it post pitching because, well, it wouldn’t be very wise to fatigue their bodies before they pitch.  They also do it to increase systemic circulation, the theory being that increasing blood flow will enhance the body’s recovery and ease soreness.  To me, this makes more logical sense than an ice pack.

Daniel Stern in "Rookie of the Year."

Daniel Stern in “Rookie of the Year.”

The body’s normal response to trauma is what we call inflammation.  The inflammatory cycle results in an increase in tissue temperature, redness, localized blood flow, possible swelling, and pain.  The degree of inflammation depends on the nature and severity of the trauma.  Pitchers who haven’t been injured and just finished an outing are not dealing with localized swelling and redness.  Pain is minimal so we call it soreness.  The increased blood flow brings to the damaged site the mechanisms for healing.  If more blood flow is present, it’s logical that more healing agents will arrive and the waste products will be removed quicker.  This relates more to the inflammatory phase than it does to removing lactic acid from the blood.  Sprint intervals will get the heart rate up, but by doing so, also creates more lactic acid.  This byproduct of exercise appears to resolve independently of external interventions.

As far as muscular soreness is concerned, icing may not be the most effective remedy.  Going back to the occasional pitcher who asked for my recommendations, what I would suggest was trying a routine of post pitching rotator cuff exercises with light weights/high reps, what we would call a “cuff flush.”  I also liked using the UBE, upper body ergometer or arm bike, to increase upper limb blood flow.  This type of exercise is not an anaerobic bout, therefore, not relying solely on glucose as its fuel and not adding to the lactic acid accumulation.  Most athletes experience their greatest muscular soreness either the next day or the day after that.  My typical routine for treatment, then, would address this with a soft tissue treatment of one or more massage and stretching techniques.  My philosophy on it is in keeping the muscles in a more elastic and pliable state.  Applying ice does decrease tissue temperature, and therefore, reduces its elasticity.  It also decreases localized blood flow.  Both are counterproductive to the goal I try to achieve in the management of muscular soreness.  That being said, the decreases in tissue temperature and elasticity are temporary, which is why I never refused to give ice to an athlete who requested it.

Shoulder internal rotation stretching.

Shoulder internal rotation stretching.

Inflammation is not the enemy.  I say the same thing about carbs.  You don’t need that South Beach diet, and you don’t need to pump yourself full of anti-inflammatory meds and cover your body in ice packs.  A well conditioned athlete should be able to fully recover from minor soreness without those things.

Continued research is needed on the topic in order for the medical and athletic communities to come to a sound conclusion on it.  Ice certainly has its uses.  An acute ankle sprain typically results in a swollen and painful joint.  Ice can help manage the swelling early on.  Keep in mind that swelling is part of healing process, but too much of it can certainly be detrimental and problematic.  For athletes dealing with routine muscular soreness, rest and light aerobic exercise may be a more effective strategy at aiding recovery.

IV.  A lighter bat results in more power.

FACT (with certain conditions)

Remember when Sammy Sosa and Albert Belle were found to be using corked bats?  What were they doing?  Let’s get biomechanical for a moment.  There are some principles here that will explain why bat regulations are in place for good reason.

Sammy Sosa of the Chicago Cubs walks to the batting cage prior to a game on June 4, 2003 -- the day after he was ejected for using a corked bat. Photo: Jonathan Daniel, Getty Images

Sammy Sosa of the Chicago Cubs walks to the batting cage prior to a game on June 4, 2003 — the day after he was ejected for using a corked bat. Photo: Jonathan Daniel, Getty Images

It should be obvious that a lighter bat can be swung with greater velocity.  But what is also part of the equation here is the length of the bat, which is why we have the drop standards for bats, which is typically a -3 (ie. 34 inch bat, 31 ounce weight).  In linear kinematics, velocity is constant at every point on the bat.  However, in angular kinematics, the velocity increases the farther away from point of axis.  Let’s imagine this in the baseball example.  We can say the point of axis is where the player grips the bat.  An argument could be made that the point of axis is actually in the hips or core of the player himself, but let’s keep this simple.  If his linear velocity of the swing is 70mph, it will be 70mph at every point along the handle and barrel.  However, since the swing is a rotational movement, we need to look at in terms of angular velocity.  Since the farther away from the axis we get, each point has to travel a longer angular distance in the same amount of time, the angular velocities get larger.  Now, we all know that there is a sweet spot on the barrel, and so hitting the ball off the very end of the bat is not advantageous to the hitter, but we can point to the sweet spot as the ideal place to make contact and move on.  A longer bat will have a sweet spot farther away from the axis than a shorter bat.

Kinetics/Kinematics of Baseball Bat Swing

Kinetics/Kinematics of Baseball Bat Swing

Torque is the rotational force generated by a moving arm in biomechanical terms.  The goal in baseball is to achieve a great amount of torque, which will result in more power.  The equation is simple.  Torque is the result of force x the perpendicular distance from the axis.  Force is calculated by mass x acceleration.  In baseball terms, the faster we can swing a bat, the more force.  If we can swing a heavier bat at the same speed, that equates to more force.  You can play around with the variables a bit to achieve similar outcomes.  The perpendicular distance is our sweet spot that we just talked about.  I know what you’re thinking.  Your head feels like a bunch of monkeys fighting over a bucket of marbles.  It’s good to break a mental sweat every now and then, right?  Continuing on…

Confused Jackie

Corking a bat removes some of the weight, while hopefully not affecting the integrity of the bat itself.  A player swinging a corked bat can generate more speed and more acceleration, more force, and thus, more torque.  Dropping the weight of a 34 inch bat by just two ounces results in a roughly 7% increase in torque.  This clearly gives them an advantage in performance.  Without any bat regulations, who knows what types of length/weight ratios we’d see, or what types of wood would be used to construct bats of immense capabilities.  Things would easily get out of hand.

I recall Sosa’s so-called excuse that he only used that bat for batting practice to give the fans a good show and somehow it made its way into the game, but let’s be honest, he was cheating.  Under the MLB regulations, a lighter bat is also shorter.  It has a sweet spot closer to the axis of rotation, which is why hitters know what size and weight is best for them.  In legal bats, you have to sacrifice some length for a drop in weight, so the trade off is negligible.  These regulations are in place to keep the bats from becoming too weaponized, for lack of a better term.

Please submit your baseball questions to @ManiacBall on Twitter, or in the comments section below.

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