Vest Cooling For The Baseball Catcher

In the game of baseball, most of the attention is focused on the pitcher. We are always continuing to research multiple avenues on how to enhance performance for the baseball pitcher. But what about the guy behind the dish?

Catchers are often beaten and scarred at the end of regulation play. Speaking from experience, catching for a doubleheader in the middle of the summer heat is difficult.

Is there a way we can optimize performance for the baseball catcher during a game?

Could it be as simple as staying hydrated, regulating body temperature to prevent heat exhaustion, or wearing an ice vest?

A recent study looked at the effects of intermittent vest cooling on increasing in-game performance for baseball catchers.

Since the game of baseball is mostly played during the hottest months of the year, the use of vest cooling may decrease perceived physical exertion, recovery heart rate, and core body temperature.

This study showed that the use of vest cooling for 4-minutes between innings in simulated games decreased core temperature, cardiovascular strain, and perceived exertion.

The subjects in this study who used the vest cooling also saw a greater perceived recovery status, meaning that they felt more recovered throughout the game.

But couldn’t ice reduce the amount of activity of your working muscles? The 4-minute interval between innings showed no negative effects on muscle temperature and body awareness!

Reducing core temperature and cardiovascular strain during competition allows for the player to increase the amount of work performed.

However, future research is needed to fully understand the mechanisms of intermittent vest cooling for baseball performance.

In this study, subjects only performed catching a fixed number of pitches during a simulated game and were not asked to hit or run the bases, as this would result in an increase in total work performed.

As a rule of thumb, I would give the baseball catcher a quick checklist throughout the game:

  1. Am I hydrated enough?
  2. Am I able to take deep breaths between innings and get my heart rate down?
  3. Is there a bag of ice readily available in the dugout if I feel overheated?

As we learn more, using a cooling vest seems like it may have a future in the game.

 

 

Bishop, SH, Szymanski, DJ, Ryan, GA, Herron, RL, and Bishop, PA. The effect of intermittent vest cooling on thermoregulation and cardiovascular strain in baseball catchers. J Strength Cond Res 31(8): 2060–2065, 2017—Baseball catchers are exposed to multiple physiological challenges while playing out- side during the spring and summer months, many of which deal with recovery and thermoregulation. The purpose of this study was to investigate the effect of intermittent cooling on core temperature, cardiovascular strain, exertion, and recovery during a simulated catching performance in the heat. Six trained college-aged baseball catchers performed in a controlled, hot (358º C), and humid (25% relative humidity) environment in a counter-balanced, cross-over design. Ice vest cooling (VC) was used as a cooling modality and was compared with a control of no cooling (NC). Rectal temperature (Tre), heart rate (HR), rating of perceived exertion (RPE), and perceived recovery scale (PRS) were recorded before and after each simulated inning. All activities took place in a heat chamber, and each inning consisted of catchers receiving 12 pitches in their position followed by 6 minutes of recovery. Nine total innings were performed, and 27 total innings were performed with each of the 2 treatments. A significantly smaller mean Tre change was seen in VC when compared with NC (0.58 ± 0.28° C, 0.98 ± 0.28° C, p ≤ 0.01, respectively). Rating of perceived exertion was significantly lower and PRS was significantly improved for VC compared with NC (both p ≤ 0.05). Mean recovery HR during VC was significantly lower than NC in the fifth (VC = 84 ± 8 b*min-1, NC = 90 ± 9 b*min-1, p = 0.04), seventh (VC = 84 ± 3 b*min-1, NC = 92 ± 7 b*min-1, p=0.02), and ninth (VC = 85 ± 7 b*min-1, NC = 93 ± 5 b*min-1, p = 0.01) innings. Heart rate during catching was significantly lower at the end of the VC trials when compared with NC (108 ± 16 b*min-1 vs. 120 ± 19 b*min-1, p = 0.02, respectively). Vest cooling decreased heat strain, cardiovascular strain, and RPE while it improved perceived recovery in catchers over a simulated 3-game series performed in hot conditions.

Research Review: Weighted Implements and Swing Velocity

Hitting success in the game of baseball can be classified with three distinct factors: decision time, swing velocity, and exit velocity.

Since exit velocity can be influenced by the first two factors, is there a way we can enhance swing velocity before stepping into the batter’s box?

Previous researchers have tried to determine if swinging a slightly lighter or slightly heavier bat can enhance swing velocity.

Decision time and swing velocity have an inverse relationship: having more time to decide in swinging the bat will need a quicker swing velocity.

In this present study, subjects performed a swinging warm up with either a lighter plastic bat, normal game bat, or a significantly heavier bat.

The results showed that there were no significant differences in swing velocity before the swing intervention.

However, after the different swing warm ups, the plastic bat seemed to increase swing velocity post-warm up, with no significant difference from the normal game bat.

Adding to the body of research, this study shows that swinging a heavier bat can decrease swing velocity.

Although this new information adds to the body of research, the subjects rested for 2-3 minutes between their warm up trial, which may not be enough time in a normal game situation.

Previous research determined that swinging a bat within a 10% range of your normal game bat can still enhance swing velocity without altering swing mechanics. The heavy bat used in this study was almost 200% greater in mass!

If you want to optimize your swing velocity in the batter’s box, it is recommended to use a bat that you are comfortable with. A significantly heavier bat may decrease your swing velocity, so it’s important to stay within the 10% range of your normal game bat.

Evaluating the effects of underloaded and overloaded warm ups on subsequent swing velocity.

Several attempts to identify the optimal on deck procedure to enhance swing velocity in baseball have been made. However, inconsistent findings continue to constitute much of the body of literature. Additionally, the emergence of athlete monitoring in sport has led to the exploration of more sport specific tasks to potentially identify athlete fatigue and readiness to perform. Therefore, the purpose of this investigation was to examine three different bat weight warm up protocols on subsequent swing velocity and to examine the reliability of swing velocity measurements to allude to its potential a sport specific athlete monitoring metric. Thirty-two recreational male baseball players (20.3 ± 2.0years, 179.6 ± 7.1cm and 89.6± 11.1kg) completed the study. Subjects completed three testing visits that included warming up with a control bat ([CB] 32in, 29oz), plastic bat ([PB] 31in, 6.4oz), or heavy bat ([HB] 32in, 57oz). Testing visits began with three CB swing trials followed by three intervention bat trials, then concluded with three additional CB swings. Swing velocity was assessed using visual 3D technology. Analyses of variance indicate that following the PB (26.6 ± 2.0m/s) and CB interventions (26.2 ± 1.7m/s) significantly faster (p<0.001) swing velocities were generated when compared to the traditional HB intervention (24.1 ± 2.2m/s). When assessed for reliability, the average ICC was 0.681 and Chronbach’s alpha was 0.95 indicating exceptional reliability. Congruent to previous research, this data bolsters the notion that warming up with a HB can hinder swing velocity. However, in contrast to previous research this data suggests that using a PB can increase swing velocity significantly. Furthermore, visual 3D can be designated as an exceptionally reliable device to measure swing velocity.

Total Motion Release: A New Warm-Up Approach

There is no surprise that baseball is a very one-sided sport. Due to this one-sidedness, baseball athletes present an adaptive muscular tightness and weakness in their throwing shoulder from repetition after repetition.

There is also no surprise that one of the most common techniques to improve joint range of motion and structural alignment is through static stretching. Contrary to popular belief, it may not affect throwing velocity.

Static stretching may be a good tool to pull from the tool box, but it may not have the greatest carry over since throwing a baseball is a dynamic activity.

However, what might surprise you is that there is a new method being used called Total Motion Release (TMR).

The TMR system assesses the body as a unified symphony of joints, like the Functional Movement Screen (FMS), to determine pain or dysfunction in one area that is affected by movements that take place elsewhere in the body.

The TMR system has six different movements to assess dysfunction and asymmetry. In this present study, the researchers only used the Standing Trunk Twist and Standing Arm Raise.

The TMR system was compared to a general dynamic warm up to determine which method was superior in increasing total range of motion in the throwing shoulder.

All 20 subjects performed both the TMR and dynamic warm up. However, in the cross-over design of the study, one group performed the TMR following the dynamic warm up and vice versa.

The results of the study showed that the TMR system significantly improved total range of motion in the throwing shoulder when compared to the general dynamic warm up.

The results also showed that there was also a time effect. Those who performed the TMR following the dynamic warm up significantly improved total joint range of motion when compared to the group who performed the TMR first.

A general dynamic warm up is important for increasing blood flow, tissue extensibility, and neuromuscular communication. To get the biggest bang for your buck, perform your dynamic warm up first, and then follow it up with using controlled movements from the TMR system.

Future research is needed to determine the retention rate of the range of motion improvements following the TMR system.

For example, between innings, 6-hours post pitching, 12-hours post pitching, 24-hours post pitching, as well as its effects on athletic performance such as throwing velocity, total innings pitched, etc.

Comparing the immediate effects of a total motion release warm-up and dynamic warm-up protocol on the dominant shoulder in baseball athletes.

A decrease in total range of motion (ROM) of the dominant shoulder may predispose baseball athletes to increased shoulder injury risk; the most effective technique for improving ROM is unknown. The purpose of this study was to compare the immediate effects of Total Motion Release® (TMR®) to a generic dynamic warm-up program in baseball athletes. Baseball athletes (n=20) were randomly assigned to an intervention group: TMR® group (TMRG; n=10) or traditional warm-up group (TWG; n=10). Shoulder ROM measurements were recorded for internal (IR) and external (ER) rotation, the intervention was applied, and post- measurements were recorded. Each group then received the other intervention and post- measurements were again recorded. The time main effect (p ≤ .001) and the time x group interaction effect were significant (p ≤ .001) for IR and ER. Post hoc analysis revealed TMR® produced significant increases in mean IR (p ≤ .005, d = 1.52) and ER (p ≤ .018, d = 1.22) of the dominant shoulder initially. When groups crossed-over, the TMRG experienced a decrease in mean IR and ER following the dynamic warm-up, while the TWG experienced a significant increase in mean IR (p ≤ .001, d = 3.08) and ER (p ≤ .001, d = 2.56) following TMR® intervention. TMR® increased IR and ER of the dominant shoulder more than a dynamic warm-up. Dynamic warm-up following TMR® also resulted in decreased IR and ER; however, TMR® following dynamic warm-up significantly improved IR and ER. Based on these results, TMR® is more effective than a generic dynamic warm-up for improving dominant shoulder ROM in baseball players.

Push Off Ground Reaction Force and Ball Speed in High School Pitchers

Many pitching coaches teach young players to either stay “tall and fall” or push as hard off the mound as they can when delivering a pitch to home plate. Is one method more optimal than the other?

If you want to throw hard, you must be able to produce force into the ground that will propel you in a forward direction towards home plate. The linear momentum that is created contributes to rotation of the trunk before ball release.

These movement sequences have been studied before in college-aged pitchers, and previous research has shown that college pitchers threw hardest when producing a high amount of force into the mound.

However, these same sequences have not been studied in the high school population.

A recent study looked at the role of push off and ground reaction force during the throwing motion on throwing velocity in high school aged pitchers.

Of the 52 pitchers that were analyzed, the results showed a significant relationship between ball speed and ground reaction force.

During the push off, horizontal ground reaction force reached around half the body weight of the player, which previous research has shown greater metrics in collegiate pitchers. While there was a statistically significant correlation between push off force and ball speed, it was weakly correlated.

These results tell us that high school aged pitchers are not utilizing their lower half when producing a pitch to home plate.

While the weak relationship may be due to poor hip musculature and general strength, poor motor control of the trunk, and lack of movement awareness, it may also indicate that while push off force is important, factors such as height, weight, and physical maturity are more important for high school aged pitchers.

According to the researchers, peak rotation velocity of the pelvis must be achieved prior to peak rotation of the trunk.

As a rule of thumb, if you want to throw hard and be successful on the mound, focus on these key variables:

  1. Get stronger in the weight room, and train to use this strength in a powerful manner
  2. Work on push off force and momentum when throwing your bullpens
  3. Include dynamic exercises that highlight the coordination between the trunk and pelvis

 

 

The relationship between the push off ground reaction force and ball speed in high school aged pitchers.

Baseball pitching is a sequential movement that requires transfer of momentum from the lower extremity to the throwing arm. Therefore, the ground reaction force (GRF) during push off is suggested to play a role in production of ball speed. The purpose of this study was to investigate the correlation between GRF characteristics during push off and ball speed in high school baseball pitchers. A total of 52 pitchers performed fast pitches from an indoor pitching mound. A force plate embedded in an indoor mound was used to capture the push off GRF. The GRF characteristics (peak anterior, vertical, and resultant forces, vertical and resultant forces at the time of peak anterior GRF, and impulse produced by the anterior GRF) from the three fastest strike pitches from each pitcher were used for analyses. Spearman’s rank correlation coefficients were used to describe the relationships between ball speed and the GRF characteristics. Ball speed was only weakly correlated with peak resultant force (r=.32, p=.02), and vertical (r=.45, p<.001) and resultant (r=.42, p=.002) forces at the time of peak anterior force. The ball speed was not correlated with other variables. The correlation between ball speed and push off force in high school pitchers was weak, especially when compared to what was reported for adult pitchers in other studies. Unlike for adult pitchers, higher push off force is only weakly correlated with ball velocity in high school pitchers, which suggests that training to better utilize body momentum may help high school pitchers improve ball speed.

Defining Long Toss

A recent study out of Wake Forest in the Orthopedic Journal of Sports Medicine looked at the perceived definition of a long toss program by pitchers, pitching coaches and athletic trainers associated with Major League Baseball. The ultimate goal was to see the differences, if any, in how players and teams incorporate these programs into daily programs, including rehabilitation.

The study showed that long toss distances were longer if utilized by the pitcher or pitching coach compared to when an Athletic Trainer employed the program. Also, there was considerable variation in throwing mechanics when throwing on a line and when the athlete would utilize a crow hop.

One possible explanation between these differences may be that players performing a long toss program designed by an athletic trainer were likely rehabilitating back from a pitching injury, while pitching coaches were just performing daily long toss between outings.

The results of this study show that there is considerable variation in the use and rationale behind a long toss program. Players, coaches and athletic trainers need to understand the implications  and demands of a long toss program in order to maximize their use between starts and in the rehabilitation setting. It may be most beneficial to use multiple variations of long toss programs that best suit the athlete and the goals of the throwing program, such as one form for rehabilitation and another for healthy players.

 


 

Defining the Long-Toss: A Professional Baseball Epidemiological Study

Austin V. Stone, MD, PhD, Sandeep Mannava, MD, PhD, Anita Patel, Alejandro Marquez-Lara, MD, and Michael T. Freehill, MD

Background: Despite widespread use of long-toss throwing in baseball as a component of arm conditioning, interval throwing programs, and rehabilitation, long-toss distance and throwing mechanics remain controversial.

Purpose: To ascertain the perceived definition of long-toss throwing through a survey of professional pitchers, pitching coaches (PCs), and certified athletic trainers (ATCs) associated with Major League Baseball.

Study Design: Descriptive epidemiology study.

Methods: Pitchers, PCs, and ATCs associated with 5 Major League Baseball organizations completed an anonymous survey that collected demographic data, personal use of long-toss throwing, and their perception of the distance and throwing mechanics that comprised long-toss.

Results: A total of 321 surveys were completed by 271 pitchers, 19 PCs, and 31 ATCs. For all respondents, the mean distance considered as long-toss was 175 ft (95% CI, 170-181 ft). Respondents categorized the throwing mechanics of long-toss, with 36% reporting throwing “on a line” and 70% reporting long-toss as “not on a line.” Of those throwing “on a line,” 28% reported using crow-hop footwork while 60% used crow-hop footwork when throwing “not on a line.” Interpretation of long-toss distance significantly varied by position: pitchers, 177 ft (95% CI, 171-183 ft); PCs, 177 ft (95% CI, 155-200 ft); and ATCs, 157 ft (95% CI, 144-169 ft) (P = .048). When asked when long-toss throwing is used, pitchers reported using it more frequently in preseason (P = .007), during the season (P = .015), and in the off-season (P = .002) compared with that by ATCs. Functional goals for long-toss throwing demonstrated that pitchers and PCs use long-toss for shoulder stretching more frequently than ATCs (P < .001 and P = .026, respectively). ATCs used long-toss more than pitchers for interval throwing programs (P < .001).

Conclusion: The definition varies for long-toss throwing distance and throwing mechanics. Pitchers and PCs believe that long-toss comprised longer distances than ATCs and employed long-toss differently for strength conditioning, training, stretching, and rehabilitation. This discrepancy highlights a potential lost opportunity for protecting the shoulder. While long-toss is an important tool, a more scientific definition is warranted to better elucidate its role in enhancing throwing performance and rehabilitation.

 

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5315237/

Changes in Pitching Mechanics Over the Course of a Game

 

One of the keys to pitching effectively is the ability to reproduce consistent mechanics and maintain your release point while on the mound.

In the past, we have found that baseball pitchers tend to become more upright as the game goes on.  Essentially, the lead knee and trunk are more upright from what would likely be fatigue of the legs.  It’s no wonder that baseball pitchers tend to leave pitches up in the zone as they become tired.

To date, we haven’t looked at this in youth pitchers, however a recent report out of AJSM sought to quantify any potential biomechanical changes in pitches aged 14-16 at the end of game.  The authors noted similar findings.  Your glove side landing leg tends to become tired and more upright, however, the authors also noted a decrease in pitching velocity and in the amount of rear leg drive and power.

In order to best develop baseball pitchers, we need to understand what happens to the body as they pitch.  Based on this information, high school age baseball pitchers should include a proper strength and conditioning program designed to maintain leg strength and power development during the course of a game.

 


Changes in Lower Extremity Kinematics and Temporal Parameters of Adolescent Baseball Pitchers During an Extended Pitching Bout

BACKGROUND: Few studies have investigated detailed 3-dimensional lower extremity kinematics during baseball pitching in adolescent athletes during extended play. Changes in these parameters may affect performance outcomes.

PURPOSE: To investigate whether adolescent baseball pitchers experience changes in lower extremity kinematics and event timing during a simulated game-length pitching bout.

STUDY DESIGN: Descriptive laboratory study.

METHODS: Twelve male adolescent pitchers (aged 14-16 years) threw 6 sets of 15 fastball pitches from an artificial pitching mound to a target at regulation distance. Joint angles and angular velocities at the hip, knee, and ankle of both legs were collected throughout the phases of the pitching cycle as well as stride length, pelvis orientation, pitch duration, timing of foot contact and ball release, ball speed, and pitching accuracy. Paired t tests ( P < .05) were used to compare the dependent variables between the last 5 pitches of the second (baseline) and sixth (final) sets.

RESULTS: During the stride phase, decreased maximum angular excursions for hip extension (baseline: 14.7° ± 9.8°; final: 11.6° ± 10.3°; P < .05) and ankle plantar flexion (baseline: 30.2° ± 14.5°; final: 24.2° ± 15.3°; P < .05) as well as maximum angular velocity for knee extension (baseline: 144.9 ± 63.3 deg·s-1; final: 121.7 ± 62.0 deg·s-1; P < .05) were observed between sets in the trailing leg. At foot contact, pitchers had decreased hip flexion (baseline: 69.5° ± 10.1°; final: 66.5° ± 11.8°; P < .05) and increased hip abduction (baseline: 20.7° ± 8.9°; final: 25.4° ± 6.0°; P < .05) in the leading leg in the final set. Compared with the baseline set, ball speed significantly decreased in the final set (29.5 ± 2.5 m·s-1 vs 28.3 ± 2.5 m·s-1, respectively; P < .05).

CONCLUSION: Kinematic changes and decreased ball speeds observed in the final set suggest that adolescent pitchers are unable to maintain lower extremity kinematics and performance as a result of extended play.

CLINICAL RELEVANCE: The results from this study may warrant further investigation into how altered lower extremity kinematics may affect trunk and upper extremity function, performance, and risk of injuries during pitching in adolescent athletes, particularly during actual game play.

 

Source: Am J Sports Med. 2017 Apr;45(5):1179-1186. doi: 10.1177/0363546516687289. Epub 2017 Feb 3.

Is Rotator Cuff Strength the Key to Preventing Tommy John Injuries?

I like simple studies that answer complex answers.  A recent report in the International Journal of Sports Physical Therapy has shown the baseball pitchers with Tommy John injuries have weaker rotator cuff strength than healthy players.

This has long been studied and shown previously but the I really liked how the authors conducted this study.  Two things stand out to me from these results that have considerable implications.  Baseball players with Tommy John injuries had:

  1.  7% deficit in ER rotator cuff strength compared to their non-throwing arm.  Healthy players had no deficit between their shoulders.
  2. 30% deficit in ER rotator cuff strength compared to the throwing arm of healthy players.

So, players with Tommy John injuries were weaker in general and showed specific throwing arm weakness.  I’ve always said that shoulder strength and mobility is the key to reducing these Tommy John injuries, these results completely support the need for rotator cuff strength.

 

EBP Reinold Throwers Arm Care ProgramDownload Our Free Throwers Arm Care Program

So it’s pretty obvious that we should be performing a shoulder program.  I’ve recently put together a free arm care program for EBP that you can perform to get your shoulder and forearm strong, and hopefully prevent some of these Tommy John injuries.

 

 


Baseball Players With Ulnar Collateral Ligament Tears Demonstrate Decreased Rotator Cuff Strength Compared To Healthy Controls

Background: Ulnar Collateral Ligament (UCL) tears are common in baseball players. Alterations in rotator cuff strength are believed to be associated with injury to the shoulder and/or elbow in baseball players.

Hypothesis/Purpose: Baseball players diagnosed with a UCL tear will demonstrate decreased internal (IR) and external rotation (ER) force as an indication of isometric muscular strength in the throwing arm compared to IR and ER force of the throwing arm in healthy baseball players. The purpose of this study was to examine isometric IR and ER strength of the shoulder in baseball players with UCL tears at the time of injury compared to healthy baseball players.

Study Design: Case‐control study design

Methods: Thirty‐three of the participants were diagnosed with a UCL tear and thirty‐three were healthy, age‐ and positioned‐matched controls. All of the participants played baseball at either the high school or collegiate level and volunteered for the study. Isometric rotator cuff strength measurements for internal (IR) and external rotation (ER) were performed with the arm held to the side at 0 ° of shoulder abduction. All measurements were taken bilaterally and the means of the throwing and non‐throwing arms for IR and ER in the UCL group were compared to the means of the throwing and non‐throwing arms in the healthy group. One‐way ANOVAs were used to calculate differences between groups (p < 0.05).

Results: Baseball players with UCL tears demonstrated significant rotator cuff strength deficits on their throwing arm IR (p < .001) and ER (p < .001) compared to throwing arm IR and ER in the Healthy (UCL IR = 131.3 ± 31.6 N; Healthy IR = 174.9 ± 20.7 N) (UCL ER = 86.4 ± 18.3 N; Healthy ER = 122.3 ± 18.3 N). On the non‐throwing arm, the UCL group was weaker in both IR (135.0 ± 31.1 N; p < .001) and ER (93.4 ± 22.8 N; p < .001) than IR (172.1 ± 24.1 N) and ER (122.3 ± 19.1 N) in the Healthy group.

Conclusion: Participants with a UCL tear exhibit lower force values as an indication of isometric rotator cuff strength in both the throwing and non‐throwing arms than a healthy cohort.

Int J Sports Phys Ther . 2015 Aug; 10(4): 476–481. BASEBALL PLAYERS WITH ULNAR COLLATERAL LIGAMENT TEARS DEMONSTRATE DECREASED ROTATOR CUFF STRENGTH COMPARED TO HEALTHY CONTROLS Copyright © 2015 by the Sports Physical Therapy Section Abstract Background Ulnar Collateral Ligament (UCL) tears are common in baseball players.

Source: Baseball Players With Ulnar Collateral Ligament Tears Demonstrate Decreased Rotator Cuff Strength Compared To Healthy Controls

How a Bad Night Sleep Impacts Pitching Performance

A recent research report investigated the effect of travel on Major League Baseball teams and performance.  The authors found the MLB teams traveling eastward, such as those ending a series in Seattle and starting traveling to their next one in Boston, had an impairment in performance.

They authors found that some offensive statistics decreased, but pitching performance was the most impacted.  Pitchers traveling eastward with at least a 2-hour time difference allowed more home runs.

The results could be explained by the effect of jet-lag on the body’s circadian rhythms.  This likely resulted in fatigue that could have reduced velocity and command.

In my experience with the Red Sox, we often times sent our next starting pitcher to the next city early to assure they could get a good night sleep and be prepared for the game the next day.

Based on this information, I think it’s easy to say that a good night sleep the night before a start is very important for your pitching performance.

 

How jet lag impairs Major League Baseball performance.

Proc Natl Acad Sci U S A. 2017 Jan 23;:

Authors: Song A, Severini T, Allada R

Abstract
Laboratory studies have demonstrated that circadian clocks align physiology and behavior to 24-h environmental cycles. Examination of athletic performance has been used to discern the functions of these clocks in humans outside of controlled settings. Here, we examined the effects of jet lag, that is, travel that shifts the alignment of 24-h environmental cycles relative to the endogenous circadian clock, on specific performance metrics in Major League Baseball. Accounting for potential differences in home and away performance, travel direction, and team confounding variables, we observed that jet-lag effects were largely evident after eastward travel with very limited effects after westward travel, consistent with the >24-h period length of the human circadian clock. Surprisingly, we found that jet lag impaired major parameters of home-team offensive performance, for example, slugging percentage, but did not similarly affect away-team offensive performance. On the other hand, jet lag impacted both home and away defensive performance. Remarkably, the vast majority of these effects for both home and away teams could be explained by a single measure, home runs allowed. Rather than uniform effects, these results reveal surprisingly specific effects of circadian misalignment on athletic performance under natural conditions.

PMID: 28115724 [PubMed – as supplied by publisher]

Source: How jet lag impairs Major League Baseball performance.

Resting Heart Rate Variability Among Professional Baseball Starting Pitchers

Heart rate variability (HRV) can be an important metric for athletes to measure recovery and response to stress.  A recent research report was published looked at HRV between starts in professional baseball pitchers.

The results indicate that changes to the autonomic nervous system were present on the day after a start, but returned to baseline the next day.  This indicates a certain level of stress the day after a start, which would help justify a lighter day of training and recovery-based activities.

We all know that pitching performance decreases with fatigue.  The authors recommend each pitcher measure their HRV daily over the course of a season to best monitor overtraining.  Certainly interesting and something to keep an eye on in an attempt to develop a system of customizing pitchers’ training and workloads between starts.

I also wonder the implications of monitoring relievers to assess potential overtraining over the season.  Hope someone measures this in the future as well.

 

Abstract: Cornell, DJ, Paxson, JL, Caplinger, RA, Seligman, JR, Davis, NA, and Ebersole, KT. Resting heart rate variability among professional baseball starting pitchers. J Strength Cond Res 31(3): 575–581, 2017—The purpose of this study was to examine the changes in resting heart rate variability (HRV) across a 5-day pitching rotation schedule among professional baseball starting pitchers. The HRV data were collected daily among 8 Single-A level professional baseball starting pitchers (mean ± SD, age = 21.9 ± 1.3 years; height = 185.4 ± 3.6 cm; weight = 85.2 ± 7.5 kg) throughout the entire baseball season with the participant quietly lying supine for 10 minutes. The HRV was quantified by calculating the natural log of the square root of the mean sum of the squared differences (lnRMSSD) during the middle 5 minutes of each R-R series data file. A split-plot repeated-measures analysis of variance was used to examine the influence of pitching rotation day on resting lnRMSSD. A statistically significant main effect of rotation day was identified (F4,706 = 3.139, p = 0.029). Follow-up pairwise analyses indicated that resting lnRMSSD on day 2 was significantly (p ≤ 0.05) lower than all other rotation days. In addition, a statistically significant main effect of pitcher was also identified (F7,706 = 83.388, p < 0.001). These results suggest that professional baseball starting pitchers display altered autonomic nervous system function 1 day after completing a normally scheduled start, as day 2 resting HRV was significantly lower than all other rotation days. In addition, the season average resting lnRMSSD varied among participants, implying that single-subject analysis of resting measures of HRV may be more appropriate when monitoring cumulative workload among this cohort population of athletes.

Source: Resting Heart Rate Variability Among Professional Baseball Starting Pitchers

Humeral Retroversion Occurs in Youth Baseball Players as Young as Fourth Grade

A recent research report out of Japan continues to add to the body of evidence regarding humeral retroversion in the dominant shoulder in baseball players.  Essentially, the upper arm in baseball players has boney adaptations that occur while throwing as a youth with open growth plates.  This allows for external rotation (layback) while throwing, and is also responsible for the shift in total rotational range of motion and subsequent loss of internal rotation.

While this has been known for some time, we continue to see that this happens at an early age.  The authors of this study note that this occurred in youth athletes as young as in the 4th grade.

This boney adaptation is a requirement for throwing later in lift, showing the importance of needing to throw as a youth as young fourth grade.

Differences in humeral retroversion in dominant and nondominant sides of young baseball players.

J Shoulder Elbow Surg. 2017 Jan 25. pii: S1058-2746(16)30624-3. doi: 10.1016/j.jse.2016.11.051.

Kurokawa D1, Yamamoto N2, Ishikawa H3, Nagamoto H4, Takahashi H5, Muraki T4, Tanaka M6, Sato K6, Itoi E7.

Author information

  • 1Department of Sports Medicine and Orthopaedic Surgery, Tohoku Rosai Hospital, Sendai, Japan; Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
  • 2Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
  • 3Department of Physical Medicine and Rehabilitation, Tohoku University School of Medicine, Sendai, Japan.
  • 4Department of Orthopaedic Surgery, Kurihara Central Hospital, Kurihara, Miyagi, Japan.
  • 5Department of Orthopaedic Surgery, Kesen-numa City Hospital, Kesen-numa, Miyagi, Japan.
  • 6Department of Sports Medicine and Orthopaedic Surgery, Tohoku Rosai Hospital, Sendai, Japan.
  • 7Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan. Electronic address: [email protected]

Abstract

BACKGROUND:

The relationship between the disabled throwing shoulder and humeral retroversion has recently attracted a great deal of attention. However, none of the previous studies clarified when the side-to-side difference of humeral retroversion in young baseball players would start. This study aimed to clarify when the difference of humeral retroversion in the dominant and nondominant sides appeared in baseball players.

METHODS:

The bicipital-forearm angle in bilateral shoulders of 172 elementary school baseball players was measured by ultrasound. The bicipital-forearm angle was defined as an angle between the perpendicular line to the bicipital groove and the ulnar long axis with the elbow flexed at 90°. The correlation between the bicipital-forearm angle and the grade and the difference of the bicipital-forearm angle between the dominant and nondominant sides were analyzed.

RESULTS:

In the nondominant shoulders, the bicipital-forearm angle increased with the grade in school (r = 0.32, P < .0001), but this was not observed in the dominant shoulders. In the fourth to sixth graders, the bicipital-forearm angles were significantly smaller in the dominant shoulders than in the nondominant shoulders.

CONCLUSION:

Our findings indicated that humeral retroversion decreased with age in the nonthrowing side but not in the throwing side and that the side-to-side difference of humeral retroversion in the baseball players became obvious from the fourth grade. We assume that the repetitive throwing motion restricts the physiologic humeral derotation process and the difference became apparent from the fourth grade when the growth spurt begins in boys.