Upper Extremity and Hip Range of Motion Changes Throughout a Season in Professional Baseball Players

Motor alterations along the kinetic chain in amateur volleyball and handball athletes with shoulder pain: An observational comparative study

Overhead sports overload the shoulder complex due to movement repetition and the great amount of force created during the athletic motion, which may cause adaptations in the shoulder and lead to shoulder pain. However, overhead movements include the kinetic chain, and alterations in some of the structures throughout the kinetic chain may increase stress on the shoulder complex and be associated with shoulder pain.

PURPOSE

To compare kinetic chain components in overhead athletes with and without shoulder pain.

METHODS

Forty-one volleyball and handball athletes (21 with and 20 without shoulder pain) were included and assessed for hip internal (IR) and external rotation (ER) range of motion (ROM), hip and trunk isometric strength, trunk endurance and neuromuscular control of the lower and upper limbs (Y balance test).

RESULTS

Athletes with shoulder pain showed smaller IR ROM in both hips, lower endurance time for trunk extensors and flexors, decreased reach distance in the anterior and posteromedial direction, as well as a smaller composite score in the Y balance test (p < 0.05).

CONCLUSION

Volleyball and handball athletes with shoulder pain showed changes in ROM throughout the kinetic chain in addition to lower core endurance, and decreased neuromuscular control of lower limbs.

The COVID-19 lockdown as a model of detraining in division 1 college softball players

BACKGROUND

The COVID-19 pandemic interrupted the organized training of softball players, similar to the abrupt cessation of sports participation that can happen after an injury. Thus, the COVID-19 pandemic offers a unique model to study how sudden detraining influences softball players.

METHODS

We recruited a sample of convenience of National Collegiate Athletic Association Division 1 softball players. They participated in three data collections: pre-lockdown (Jan 2020, T1), post-lockdown (Sept 2020, T2), and before the 2021 season (Jan 2021, T3). Between T1 and T2, players received an at-home conditioning and throwing program, but compliance was not strictly monitored. Between T2-T3, players resumed formal fall training (team-organized workouts, on-field practice, and within-team scrimmage games). At each time point, we collected bilaterally: 1) shoulder internal rotation (IR) and external rotation (ER) range of motion (ROM); 2) shoulder IR and ER strength; 3) hip IR and ER ROM; and 4) hip abduction and extension strength. We used four independent (2 Sides × 3 Timepoints) MANOVA with repeated measures; we followed up significant MANOVA main effect of time with Sidak posthoc tests for pairwise comparisons between time points.

RESULTS

Fifteen players participated in this study. We found a significant MANOVA main effect of time for shoulder and hip ROM (p < 0.01). Between T1-T2, dominant shoulder ER ROM decreased 6.5°, dominant shoulder IR ROM increased 4.3°, and lead hip IR ROM increased 4.4°. Between T2-T3, dominant shoulder ER ROM increased 6.3° and trail hip ER ROM increased 5.9°. We found a significant MANOVA main effect of time for shoulder strength (p = 0.03) but not for hip strength (p = 0.18). Between T2-T3, non-dominant shoulder IR and ER increased 1.8 kg and 1.5 kg, respectively.

CONCLUSION

A sudden and prolonged cessation of organized training generated changes in shoulder and hip ROM but affected strength to a lesser extent. The loss of shoulder ER and increased lead hip IR ROM are maladaptive as they are associated with injury in overhead athletes. Resuming team-organized training and scrimmage reversed some (shoulder ER), but not all of these changes. Practitioners should monitor clinical variables regularly and be aware of potential changes due to unexpected and prolonged interruptions in training, such as when players suffer sports-related injuries.

Current concepts: the hip, core and kinetic chain in the overhead athlete

BACKGROUND

As overhead sports continue to grow in popularity, there has been increased interest in optimizing sports performance and injury prevention in these athletes. The hip, core, and kinetic chain have become a focus of research in recent decades, and their importance in upper extremity mechanics is now being recognized.

METHODS

An extensive review was carried out to identify papers correlating the hip, core and/or kinetic chain in overhead athletic performance and injury.

RESULTS

Recent literature has shown that efficiency and synchrony of the hips and core during an overhead movement (such as in baseball, golf, tennis, or volleyball) is essential for a powerful and precise execution of the task. Impairments of the hip and core, particularly abnormal joint mobility or weakness, can limit efficient energy transfer through the kinetic chain and may negatively impact performance. Recent epidemiologic studies have found hip pain to be common in adolescent, collegiate, and adult athletes. Moreover, hip pain in overhead athletes specifically has also been found to occur at a high rate. Abnormalities in hip range of motion, hip morphology, and core strength can lead to abnormal mechanics upstream in the kinetic chain, which may place athletes at risk of injuries.

CONCLUSION

In this review, the complex and multifaceted relationship between the hip, core, and kinetic chain is highlighted with an emphasis on recent literature and relevant findings.

Evaluation of Hip Characteristics in Baseball and Softball Athletes with and Without Throwing Arm Pain

During throwing, the lower extremity assists in the generation and transfer of momentum. Lower extremity stability assists in this transfer by providing a base for distal mobility of the arm segments. This study aimed to determine differences between hip rotational range of motion and strength based on the presence of throwing-arm pain (yes/no) and throwing sport (baseball/softball). We hypothesized those experiencing pain would display decreases in hip range of motion and strength, and that softball players would display greater range of motion than baseball, but less strength based on sex-specific characteristics. Forty-four baseball (13±2 years, 165.2±13.0 cm, 58.5±13.4 kg) and 50 softball players (13±2 years, 160.9±11.2 cm, 62.7±17.9 kg) participated. Multivariate analysis of variance tests (2×2) determined differences in bilateral hip range of motion, total arc of motion, and strength between pain status and sport. There were no significant interactions (>0.05) for pain status and sport on hip range of motion, total arc of motion, and strength. Furthermore, no significant main effects (>0.05) were found for pain status or sport alone on range of motion or strength. Future work should be directed at explaining the effects of hip characteristics on the throwing motion and how it equates to throwing-arm health.

Range of Motion Adaptations During a Simulated Game Exposure in Softball Pitchers

Hip and shoulder range of motion (ROM) alterations are correlated with increased risk of injury in softball athletes. The purpose of this study was to investigate bilateral shoulder and hip ROM adaptation during a simulated softball double-header exposure. It was hypothesized that shoulder and hip ROM would decrease after simulated game exposure and would not return to baseline following a 30-minute break. Thirty (14.8±1.9 yrs, 162.5±18.3 cm, 71.79±16.03 kg) adolescent softball pitchers participated. Testing included: bilateral hip and shoulder ROM (preSG), simulated game exposure (100 pitches), bilateral hip and shoulder ROM (postSG), 30-minute break, bilateral hip and shoulder ROM (preDH), pitching first inning of a simulated double header (12 pitches), and bilateral hip and shoulder ROM (postDH). Two separate repeated measures multivariate analyses of variance tests determined differences in ROM between time points. Dominant shoulder internal rotation ROM and non-dominant shoulder internal and external rotation ROM significantly decreased from preDG. Stride hip external rotation ROM and drive hip internal and external rotation ROM significantly decreased from preSG to preDH. Key results revealed the break given between games may not be sufficient recovery time for hip ROM. Thus, assessing ROM as workload progresses can be a useful strategy for monitoring a softball pitcher's injury risk.

Advancements for the Future: A National Survey of Fastpitch Softball Coaches' Perspectives on Injury Prevention Programming

Background

Approximately 50 percent of softball injuries are the result of overuse or chronic conditions. However, research exploring preventative measures for softball players is limited and usage of injury prevention strategies among softball coaches is unknown.

Hypothesis/Purpose

This survey aimed to investigate if softball coaches are implementing injury prevention programs to reduce injury and improve the performance of their players. The secondary purpose was to identify barriers to the implementation of injury prevention programs. Finally, this survey explored the coaches' knowledge of injury risk factors and their views on design and usage of preventative programs.

Study Design

Descriptive cross-sectional survey.

Methods

A 35-item survey was sent to approximately 14,000 high school and collegiate fastpitch softball coaches throughout the United States. Data were collected over a three-month period with an overall response rate of 1.2%.

Results

Among responding coaches, 45.9% (n=79/172) reported implementing injury prevention programs. Coaches who implement injury prevention strategies most frequently utilize team-based programs (68.8%, n=52/93) compared to group-based (19.0%, n=15/93) or individualized programs (15.2%, n=12/93). Coaches who do not use preventative programming reported that being unsure of what program to perform (53.8%, n=50/93) and not having enough staff (20.4%, n=19/93) were the greatest barriers to implementation. Although over 50% of coaches recognized arm fatigue/overuse (27.9%, n=48/172) and decreased core strength (22.7%, n=39/172) were important risk factors, 36% (n=94/172) "disagree" that softball pitchers should adhere to pitch counts and 90% (n=83/92) believe that preventative programming for pitchers and position players should be similar.

Conclusion

Less than 50 percent of softball coaches implement exercise programs to prevent injury. Limited familiarity with effective program design, inadequate staffing, and inconsistent risk factor awareness are the major contributors to lacking implementation. Collaboration between rehabilitation professionals and softball coaches regarding preventative programming should be considered.

Level of Evidence

Level 3©The Author(s).

Kinetic and kinematic comparisons in high school pitchers with low and high pitch location consistency

BACKGROUND

Although ball velocity has often been associated with increased kinetics at the upper extremity and risk of injury in youth and adolescent pitchers, it is unclear if the performance metric pitch location consistency has any positive or negative associations with pitching kinetics.

METHODS

High school pitchers (n = 59) pitched 8-12 fastballs using 3D motion capture (480 Hz). Pitchers were divided into high-consistency (HiCon) and low-consistency (LoCon) groups based on the absolute center deviation of each pitcher's pitch to the center of the pitcher's mean pitch location. Ninety-five percent confidence ellipses with major and minor radii were constructed, and kinematics and kinetics were compared between groups.

RESULTS

Compared with LoCon pitchers, HiCon pitchers had decreased lead hip flexion at elbow extension (40° ± 12° vs. 52° ± 13°, respectively, P = .008), and at foot contact, decreased back hip extension (-1° ± 10° vs. -10° ± 13°, respectively, P = .038) and increased back hip internal rotation (9° ± 15° vs. -2° ± 15°, respectively, P = .043). LoCon pitchers achieved maximum lead hip flexion earlier in the pitch (61.3% ± 23.2% vs. 75.8% ± 15.1%, respectively, P = .039). A multiregression model predicted 0.49 of variance in pitch location consistency using kinematic inputs.

DISCUSSSION AND CONCLUSION

Pitchers who differ in pitch location consistency outcomes do not appear to demonstrate physiologically unsafe kinematics. High school pitchers who strive for improved pitch consistency can consider adjusting parameters of hip kinematics during early portions of the pitch.

Effect of Weather and Game Factors on Injury Rates in Professional Baseball Players

BACKGROUND

Injury rates in baseball players of all ages are increasing. Identifying modifiable risk factors is paramount to implementing injury prevention programs.

PURPOSE/HYPOTHESIS

The purpose was to evaluate the influence of weather (temperature, humidity, atmospheric pressure, and heat index) and game factors (start time, duration, single vs doubleheader) on injury rates in professional baseball players. We hypothesized that colder temperatures would be associated with significantly more injuries per game.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This was a retrospective database study. Two data sets were combined: 1 containing all injuries in Major and Minor League Baseball between 2011 and 2017 and 1 containing all games played in Major and Minor League Baseball during the same period to determine the number of injuries per game. Temperature, humidity, atmospheric pressure, and heat index were determined for each game using the data from the US Environmental Protection Agency. Additional game variables included the level of play, the turf type (natural vs artificial grass), the stadium type (open vs dome vs retractable), the game start time, the game duration, and whether the game was a doubleheader. Then, a multivariate analysis was conducted to determine which factors were associated with the number of injuries per game.

RESULTS

In total, our analysis included 33,587 injuries and 76,747 games. A total of 25,776 (33.6%) games contained an injury, and 41% of injuries occurred as multiples per game, with up to 9 injuries per game. The multivariate analysis identified significant associations between game duration and injuries per game (P < .001; effect size, 0.013) and the level of play and injuries per game (P < .001; effect size, 0.011). There were significant associations between the venue type (P < .001), the game start time (P < .001), humidity (P < .001), the turf type (P = .016), and barometric pressure (P = .031); however, the effect size for each was <0.001, suggesting that these factors are clinically unimportant. Our overall model produced an R² of 0.04, indicating that these variables only predicted 4% of the variance in injury risk.

CONCLUSION

In professional baseball, the weather is not associated with injury risk; however, game duration may contribute to injury risk.

Lower extremity injuries in the baseball athlete

Baseball is unique in its multiple facets: pitching, hitting, base rounding, and fielding are distinct activities that require different athletic skills to perform at a high level. Likewise, these different aspects of the game can contribute to a multitude of varying injuries. While high-velocity overhead throwing, along with batting, can produce a plethora of upper extremity injuries that often garner attention, injuries to the lower extremity can severely impact a player’s performance and ability to compete. The rigors of the short, explosive sprinting required for base running, as well as the dynamic movement required for fielding, create ample opportunity for lower limb injury, and even subtle pathology can affect a pitcher’s ability to perform or increase their long-term risk of injury. Chronic injury from conditions such as femoroacetabular impingement and hip labral tears can also occur. The purpose of the present review is to summarize the relevant epidemiology, pathophysiology, and treatment of lower extremity injuries in baseball athletes, with reference to current research into the prevention and management of such injuries.

Seasonal and monthly trends in elbow ulnar collateral ligament injuries and surgeries: a national epidemiological study

Background

Monthly incidence of elbow ulnar collateral ligament (UCL) injuries and surgeries is relatively unknown. Defining seasonal peaks of UCL injuries and surgeries may identify opportunities for injury-prevention strategies. The purpose of this study is to analyze seasonal and monthly variations in UCL injuries and surgeries across the United States with emphasis on the timing of baseball season.

Methods

The Truven Health MarketScan database (2013-2015) was queried for patients younger than 40 years with a diagnosis code of elbow UCL sprain and a procedural code for UCL repair or reconstruction. Differences in patient characteristics were evaluated using chi-square and Mann-Whitney U-tests. Negative binomial regression models were calculated for UCL injuries and surgeries to assess monthly trends.

Results

UCL injuries were sustained by 13,894 patients, with 1404 (10.1%) patients having undergone surgery. The median age at first diagnosis was 17 years, and the median age of patients requiring surgery decreased from 20 to 18 years from 2013 to 2015 (P = .75). Most UCL injuries (n = 3785) and surgeries (n = 438) occurred during the spring season (March 21-June 20), and spring injuries were most likely to result in surgical management (11.6%). During the baseball season (March to September), the number of UCL injuries peaked in April/May, then declined, except for a second peak in September/October (incidence rate ratio 0.97; confidence interval 0.95, 0.99; P = .01). The number of UCL surgeries steadily increased from March (n = 116) to June (n = 152), followed by a gradual decline (incidence rate ratio 1.00; confidence interval 0.96, 1.04; P = .99).

Conclusion

Athletes frequently experienced UCL injuries and surgeries in the early months (April-June) of the baseball season. More emphasis should be paid to rehabilitative strategies at the beginning of a baseball season to help mitigate injury risk.

Blood Flow Restriction Enhances Rehabilitation and Return to Sport: The Paradox of Proximal Performance

The use of blood flow restriction (BFR) within rehabilitation is rapidly increasing as further research is performed elucidating purported benefits such as improved muscular strength and size, neuromuscular control, decreased pain, and increased bone mineral density. Interestingly, these benefits are not isolated to structures distal to the occlusive stimulus. Proximal gains are of high interest to rehabilitation professionals, especially those working with patients who are limited due to pain or postsurgical precautions. The review to follow will focus on current evidence and ongoing hypotheses regarding physiologic responses to BFR, current clinical applications, proximal responses to BFR training, potential practical applications for rehabilitation and injury prevention, and directions for future research. Interestingly, benefits have been found in musculature proximal to the occlusive stimulus, which may lend promise to a greater variety of patient populations and conditions. Furthermore, an increasing demand for BFR use in the sports world warrants further research for performance research and recovery.

LEVEL OF EVIDENCE

Level V, expert opinion.

Comprehensive Lower Extremities Joints Range of Motion Profile in Futsal Players

The purposes of this study were to describe the lower extremities joints range of motion (ROM) profile using a comprehensive approach in futsal players and to examine potential player position (goalkeepers vs. outfield players), competitive level (first [top] division vs. second division), number of playing years, sex (males vs. females), and bilateral (dominant limb vs. non-dominant limb) differences. A total of 72 male and 67 female elite futsal players from 11 clubs were measured of passive hip (flexion with knee flexed [HF_KF] and extended [HF_KE], extension [HE], abduction [HA], external [HER], and internal [HIR] rotation), knee (flexion [KF]) and ankle (dorsiflexion with knee flexed [ADF_KF] and extended [ADF_KE]) ROMs. Bayesian inferences exploring differences between player position, competitive level, sex and limb were made. A Bayesian correlation analysis was conducted to explore the influence of playing years on joints ROMs. The results showed no significant player position or competitive level related differences in any average ROM score. However, statistically significant sex-related differences were documented whereby female players reported higher hip and knee joints ROM average values than their male counterparts. Especially relevant were the proportions of males (72%) and players from teams engaged in the second division (61%) displaying limited HF_KE ROMs. Likewise, around 35% of all players showed restricted ADF_KF ROMs. In addition, approximately 21, 18, 22, and 25% of the futsal players were identified as having bilateral asymmetries (≥8°) for HA, HIR, HER, and KF ROMs, respectively. Finally, Bayesian correlation analysis did not report any significant association between years of playing futsal and ROM measures (all r values < 0.34). The implications that these restricted HF_KE and ADF_KF ROMs and bilateral asymmetries in hip (abduction, internal and external rotation) and knee (flexion) ROMs caused by the practice of futsal may have on physical performance and injury risk warrant future research.

Offseason Workout Recommendations for Baseball Players

PURPOSE OF REVIEW

Offseason training programs are crucial for the baseball athlete. Preparation for the competitive season should be carefully planned to allow long-term athletic success. The two goals of the offseason training program are to optimize performance and reduce injury risk. These goals can only be accomplished with an understanding of the unique physical demands of the sport, and how these demands relate to performance and injury. The purpose of this article is to review the unique demands of baseball training along with current strength and conditioning principles to optimize offseason training for the baseball athlete.

RECENT FINDINGS

Traditional strength and conditioning programs used in other sports may not maximize the qualities necessary for optimal baseball performance. Traditional strength and conditioning exercises, such as squat and deadlift, primarily train sagittal plane movement while frontal and transverse plane movements are likely equally as important for baseball players. Biomechanical studies have shown that trunk rotation power has the largest influence on throwing velocity in pitchers. Programs should also be designed to reduce injury risk for common injuries. The most common injuries in baseball include hamstring strains, throwing arm injuries, paralumbar muscle strains, hip adductor strains, and oblique muscle strains. This review describes the typical periodization phases of the offseason and provides a sample program outlining an offseason program for a professional baseball player from September through February.