Recent Research Publications & Presentations

Background: Though chronic overhand throwing is known to result in range of motion and strength adaptations, there is limited research regarding interventions for maintenance of these characteristics.

Purpose: The purposes of this study were to explore the use of a pre-throwing protocol focusing on lumbopelvic-hip complex musculature in high school baseball players and examine its effects on shoulder and hip range of motion and isometric strength over the course of a season.

Study Design: Descriptive Laboratory.

Methods: Thirty-nine participants (174.14 ± 1.22 cm, 72.71 ± 13.66 kg, 15.64 ± 1.22 years) were included. Seventeen participants (172.1 ± 7.1 cm, 68.3 ± 12.0 kg, 15.5 ± 1.2 years) on the intervention team and 22 participants (175.7 ± 8.1 cm, 76.2 ± 14.1 kg, 15.8 ± 1.2 years) were included on the control team.Four exercises were added to the intervention team’s warm-up routine. The control and intervention teams’ passive bilateral hip and shoulder range of motion and isometric strength were assessed pre/post-season. A multivariate analysis of variance revealed significant differences in delta scores between the teams for multiple shoulder and hip range of motion and isometric strength variables.

Results: Key results were the intervention team lost significantly more stride hip external rotation but gained more isometric strength than the control team. The intervention team was also able to better maintain shoulder range of motion than the control team.

Conclusion: Practitioners should use the results of this study and consider incorporating exercises that target lumbopelvic- hip complex musculature into their current training program.

 

This abstract has a full manuscript that has been published in the International Journal of Sports Medicine. You can get full access at https://www.thieme-connect.com/products/ejournals/pdf/10.1055/a-1214-6278.pdf.

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Influence of a Pre-Throwing Protocol on Range of Motion and Strength in Baseball Athletes

Jessica Downs, Kyle Wasserberger, Gretchen Oliver

Background: Though chronic overhand throwing is known to result in range of motion and strength adaptations, there is limited research regarding interventions for maintenance of these characteristics.

Purpose: The purposes of this study were to explore the use of a pre-throwing protocol focusing on lumbopelvic-hip complex musculature in high school baseball players and examine its effects on shoulder and hip range of motion and isometric strength over the course of a season.

Study Design: Descriptive Laboratory.

Methods: Thirty-nine participants (174.14 ± 1.22 cm, 72.71 ± 13.66 kg, 15.64 ± 1.22 years) were included. Seventeen participants (172.1 ± 7.1 cm, 68.3 ± 12.0 kg, 15.5 ± 1.2 years) on the intervention team and 22 participants (175.7 ± 8.1 cm, 76.2 ± 14.1 kg, 15.8 ± 1.2 years) were included on the control team.Four exercises were added to the intervention team’s warm-up routine. The control and intervention teams’ passive bilateral hip and shoulder range of motion and isometric strength were assessed pre/post-season. A multivariate analysis of variance revealed significant differences in delta scores between the teams for multiple shoulder and hip range of motion and isometric strength variables.

Results: Key results were the intervention team lost significantly more stride hip external rotation but gained more isometric strength than the control team. The intervention team was also able to better maintain shoulder range of motion than the control team.

Conclusion: Practitioners should use the results of this study and consider incorporating exercises that target lumbopelvic- hip complex musculature into their current training program.

 

This abstract has a full manuscript that has been published in the International Journal of Sports Medicine. You can get full access at https://www.thieme-connect.com/products/ejournals/pdf/10.1055/a-1214-6278.pdf.

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Kinematic Differences Exist Between the Fastball, Changeup, Curveball, and Dropball Pitch Types in Collegiate Softball Pitchers

Jessica Downs, Nicole Bordelon, Kenzie Friesen, David Shannon, Gretchen Oliver

Background: A majority of softball literature focuses on the mechanics associated with pain and injury within a single pitch type per study; however, the generalizability of these findings is unknown since a kinematic comparison has yet to be performed between pitch types. Understanding kinematic differences between pitch types can be used to identify risk factors for injury, improve safety guidelines, and improve performance by linking specific mechanics with desired pitch outcomes.

Purpose: To compare kinematics between the fastball, changeup, curveball, and dropball pitch types in collegiate softball pitchers. It was hypothesized that there would be significant kinematic differences between pitch types.

Study Design: Descriptive Laboratory.

Methods: A total of 28 female collegiate softball pitchers pitched 3 trials of each pitch type to a catcher at regulation distance. Pitch speed, stride length, trunk extension, trunk rotation, trunk lateral flexion, elbow flexion, and center of mass for each trial were calculated using an electromagnetic motion capture system and were averaged for analysis. A 1-way analysis of variance (ANOVA) was used to investigate pitch speed differences between the 4 pitch types. A 4 (pitch type) × 5 (event) within-athlete multivariate ANOVA was also used to determine kinematic differences.

Results: The results revealed a significant difference in pitch speed between pitch types; a pitch type main effect for trunk extension, trunk rotation, trunk lateral flexion, and center of mass; and an event main effect for all variables except stride length. The results also revealed a pitch type by event interaction for trunk flexion, trunk lateral flexion, and center of mass. Specifically, the dropball type had less trunk extension than the fastball at all pitching events. Similarly, the curveball type had a more posteriorly shifted center of mass than the dropball at the last 3 pitching events of foot contact, ball release and follow-through.

Conclusion: Significant kinematic differences exist between pitch types, but these differences may be necessary to execute desired pitch outcomes.

 

This abstract has a full manuscript that has been published in the American Journal of Sports Medicine. You can get full access at https://journals.sagepub.com/doi/10.1177/0363546520988172?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed

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Increased Upper Arm Length and Youth Loading Rate Identified as Potential Risk Factors for Injury in Youth Baseball Pitchers

Jessica Downs, Kyle Wasserberger, Michael Saper, Gretchen Oliver

Background: In the throwing elbow, increased elbow torque has been correlated with increased injury risk. Additional insight into the relationships between anthropometric factors and elbow joint loading is warranted.

Purpose: To investigate the relationship between physical limb length characteristics, elbow kinetics, and elbow kinematics in youth baseball pitchers, and to examine the relationship between elbow varus loading rate and elbow kinetics.

Study Design: Descriptive Laboratory.

Methods: Twenty-seven (15.8 ± 2.7 years,176.3 ± 13.0cm, 71.7 ± 16.4kg) male youth baseball pitchers participated. Upper arm (UA) and forearm (FA) length were measured by using a moveable sensor to digitizing bony landmarks. Kinematic data were collected at 240 Hz using an electromagnetic tracking system. Participants threw three fastballs to a catcher at a regulation distance (60ft 6in), and the fastest velocity trial was used for analysis. Linear regression was used to determine the relationship between physical limb length characteristics, elbow kinetics, and elbow kinematics after accounting for the effects of body weight and height.

Results: Pitchers with increased UA length experienced increased maximum elbow varus torque (P = .005) and maximum net elbow force (P = .001). Pitchers with higher FA:UA had decreased elbow compression force (P < .001) and exhibited a more flexed elbow at foot contact (P = .001). Pitchers with greater maximum loading rates experienced higher elbow varus torque (P = .002).

Conclusion: In youth baseball pitchers, increased upper arm length and loading rate increase varus torques about the elbow during a fastball pitch.

 

This abstract has a full manuscript that has been published in the American Journal of Sports Medicine.

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Biceps Tendon Changes and Pitching Mechanics in Youth Softball Pitchers

Gretchen Oliver, Jessica Downs, Kenzie Friesen, Michael Saper, Adam Anz, James Andrews

Background: With the lack of pitch count regulation, youth softball pitchers are experiencing unremitting high stresses on the anterior shoulder.

Purpose: To examine the association of acute changes in the long head of the biceps tendon with pitching kinematics and kinetics in youth softball pitchers following an acute bout of pitching.

Study Design: Descriptive Laboratory.

Methods: Twenty-three softball pitchers (12.17 ± 1.50 yrs.; 160.32 ± 9.41 cm; 60.40 ± 15.97 kg) participated. To investigate the association between biceps tendon changes and kinematic and kinetic changes from pre to post-simulated game, each biceps tendon measure was split into those whose biceps tendon thickness, width, and/or area increased pre- to post-simulated game, and those whose did not.

Results: There were significant differences in biceps tendon longitudinal thickness (Z = − 2.739, p = 0.006) and pitch speed; as well as a difference between groups in biceps tendon transverse thickness and the amount of change in trunk rotation at the start of the pitching motion (p = 0.017) and the amount of change in trunk flexion at ball release (p = 0.030).

Conclusion: This study illustrates the association of trunk and lower extremity kinematics and shoulder kinetics with morphologic changes in the biceps tendon with an acute bout of windmill softball pitching.

 

This abstract has a full manuscript that has been published in the International Journal of Sports Medicine. You can get full access at https://www.thieme-connect.com/products/ejournals/abstract/10.1055/a-1236-3855.

Descriptive Profile of Shoulder Range of Motion and Strength in Youth Athletes Participating in Overhead Sports

Gretchen Oliver, Jessica Downs, Paul Camargo

Background: The unilateral and repetitive nature of overhead sports, often result in a biomechanical overload of the upper extremity. Understanding the musculoskeletal shoulder range of motion (ROM) and strength patterns in the youth sports of baseball, softball, and tennis could assist injury prevention screening and further the development of conditioning and rehabilitation programs.

Purpose: To generate a descriptive profile of shoulder musculoskeletal characteristics and determine whether bilateral differences in shoulder ROM exist in youth baseball, softball, and tennis athletes. A secondary aim was to determine whether shoulder rotational adaptations are correlated with playing position, sport, or years of experience.

Study Design: Descriptive Laboratory.

Methods: A total of 136 competitive youth overhead athletes (baseball: n=51,12.8±0.9yrs; softball: n=63,12.3±1.1yrs; and tennis: n=22,12.5±0.9yrs) participated. Bilateral shoulder internal (IR) and external (ER) passive ROM and exter­nal rotation strength were measured using an inclinometer and handheld dynamometer.

Results: Significant differences (p<.001) in bilateral shoulder ROM and ER strength were found between the athletes in the three sports. Post-hoc test revealed tennis athletes had greater bilateral shoulder ROM than both baseball and softball athletes, but baseball and softball athletes had greater bilateral ER strength than tennis athletes. There were no differences between baseball and softball athletes. Additionally, tennis athletes had greater bilateral internal rota­tion and total ROM but less ER strength than baseball pitchers, baseball positional athletes, softball pitchers, and softball positional athletes. There were no significant differences between positions and baseball and softball athletes. There were no significant correlations between playing position, sport, or years of experience.

Conclusion: The results of this study showed differences in shoulder passive ROM and strength adaptations between youth tennis, baseball, and softball athletes. The descriptive nature of this study is impactful as it presents specific ROM adaptions seen in this population. Future research is needed to further evaluate if the “at risk” ROM identified in older populations holds true in the youth population.

 

This abstract has a full manuscript that has been published in the International Journal of Sports Physical Therapy. You can get full access at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7727435/pdf/ijspt-15-1090.pdf.

Decreased Shoulder and Elbow Joint Loads During the Changeup Compared with the Fastball and Curveball in NCAA Division 1 Collegiate Softball Pitchers

Gretchen D. Oliver, Jessica L. Downs Talmage, Kenzie B. Friesen, Michael G. Saper, Jeffrey R. Dugas

Background: Baseball leagues have implemented pitch count and pitch type restrictions based on biomechanical concepts 

associated with pitch type. Softball has not yet adopted these practices, although softball pitchers continue to pitch at a high 

volume and learn multiple pitches at a young age. 

Purpose: To examine shoulder and elbow kinetics between the fastball, curveball, and changeup, as well as to provide descriptive upper extremity pain data in National Collegiate Athletic Association (NCAA) softball pitchers. 

Study Design: Descriptive laboratory study. 

Methods: Study participants consisted of 27 female NCAA Division I softball pitchers (age, 20.2 ± 1.9 years; height, 175.7 ± 5.7 cm; weight, 83.6 ± 12.7 kg). The participants pitched 3 balls of each pitch type, and kinetic data were recorded. A one-way within participants repeated-measures multivariate analysis of variance was used to determine significant differences in kinetics and pitch speed between pitch types. 

Results: Results revealed a statistically significant main effect for pitch type (Wilks 𝜆 .087; F . 36.523; P < .001). Post hoc testing showed that the changeup produced less anterior elbow force compared with the fastball (P < .001) and the curveball (P = .012). In addition, the changeup produced less shoulder distraction force compared with the fastball (P < .001) and the curveball (P = .001). Additionally, there was a significant difference in pitch speed between all 3 pitch types (P = .006). The curveball revealed no statistically significant kinetic differences compared with the fastball. 

Conclusion: The fastball and curveball placed similar stress on the upper extremity in collegiate softball pitchers. However, in 

comparison with the changeup, the fastball and curveball placed increased stress on the upper extremity. More research is needed 

to fully explain the differences seen between pitch type and injury risk. 

Clinical Relevance: Sports medicine professionals, coaches, and athletes should use the current study results to note these 

differences in shoulder distraction and elbow anterior forces between softball pitch types. The study results can be used as a 

reference and basis for future research investigating kinetic differences across varying pitch types.

Poster Abstracts

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