Limits...
The Impact of Fatigue on the Kinematics of Collegiate Baseball Pitchers.

Grantham WJ, Byram IR, Meadows MC, Ahmad CS - Orthop J Sports Med (2014)

Bottom Line: Maximum external rotation of the shoulder and elbow height at foot contact decreased over the course of a game.Elbow flexion decreased with greater season pitch counts.Recognition of kinematic alterations may better demonstrate fatigue-related injury risk and may assist injury prevention in addition to standardized limitations of innings and pitches thrown.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Columbia University Medical Center, New York, New York, USA. ; Department of Orthopaedic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA.

ABSTRACT

Background: Many factors are believed to contribute to throwing injuries in baseball pitchers, in particular overuse and poor throwing mechanics. The impact of fatigue on pitching biomechanics in live-game situations is not well understood.

Hypothesis: Pitchers will demonstrate significant deviation in their pitching motions with increasing levels of fatigue.

Study design: Descriptive laboratory study.

Methods: Eleven National Collegiate Athletic Association (NCAA) Division I collegiate baseball pitchers were filmed in multiple live-game situations throughout a single season using 2 orthogonal high-speed cameras at 120 Hz. The first fastball of each inning and, when available, the fastball subsequent to the 15th and 30th pitch of each inning were recorded and analyzed for 26 kinematic parameters. Pitch count and velocity were recorded. Kinematic differences were assessed for association with pitch count and subjective fatigue measures over the course of each inning and game through the season.

Results: Twenty-six games were recorded. Pitchers had a mean of 97.2 ± 16.1 pitches per start and 1079 ± 251 pitches per collegiate season. Increased hip lean at hand separation, elbow height at foot contact, and hip flexion and shoulder tilt at maximum external rotation were seen in innings lasting longer than 15 pitches. Maximum external rotation of the shoulder and elbow height at foot contact decreased over the course of a game. Hip lean at hand separation and elbow height at foot contact increased over the course of the season. Season pitch count was weakly correlated with increased shoulder external rotation and shoulder alignment at maximum external rotation and with shoulder abduction at ball release. Elbow flexion decreased with greater season pitch counts.

Conclusion: Hip lean, elbow height, and shoulder external rotation were the most sensitive kinematic parameters to inning, game, and season fatigue. Pitch count and fatigue have a significant impact on live-game pitching kinematics.

Clinical relevance: Fatigue likely alters pitching mechanics. Recognition of kinematic alterations may better demonstrate fatigue-related injury risk and may assist injury prevention in addition to standardized limitations of innings and pitches thrown.

No MeSH data available.


Related in: MedlinePlus

Camera positions.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2 - License 3
getmorefigures.php?uid=PMC4555605&req=5

fig1-2325967114537032: Camera positions.

Mentions: During regularly scheduled games in the spring intercollegiate season, each pitcher was filmed using 2 high-speed cameras (Qualysis Motion Capture Systems) at 120 Hz. The 2 cameras were positioned off of the baseball field, with 1 camera directly behind home plate and the other perpendicular to the arm side of the pitcher (Figure 1). The camera lateral to the pitcher was estimated to be orthogonal to the plane of the pitch. The cameras were synchronized and stationed at the same positions at each baseball field to allow for consistent measurement of kinematic parameters. The first fastball of each inning was recorded, and when applicable, the first fastball after the 15th pitch and 30th pitch of the inning were also recorded. Filming commenced with the first pitch of the game and was completed when the pitcher’s performance was done. Data such as pitch count, duration of each inning, duration of rest between innings, and pitch velocity were recorded. After the game, each pitcher completed a questionnaire rating subjective measures of fatigue. Data included a binary self-assessment of the pitcher’s ability to continue pitching and a rating of the degree of fatigue felt at the beginning and at the end of the game. Fatigue was quantified using a 10-point visual analog scale, with the player marking his level of energy on a 10-cm line between “completely fatigued” and “fully rested.”


The Impact of Fatigue on the Kinematics of Collegiate Baseball Pitchers.

Grantham WJ, Byram IR, Meadows MC, Ahmad CS - Orthop J Sports Med (2014)

Camera positions.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2 - License 3
Show All Figures
getmorefigures.php?uid=PMC4555605&req=5

fig1-2325967114537032: Camera positions.
Mentions: During regularly scheduled games in the spring intercollegiate season, each pitcher was filmed using 2 high-speed cameras (Qualysis Motion Capture Systems) at 120 Hz. The 2 cameras were positioned off of the baseball field, with 1 camera directly behind home plate and the other perpendicular to the arm side of the pitcher (Figure 1). The camera lateral to the pitcher was estimated to be orthogonal to the plane of the pitch. The cameras were synchronized and stationed at the same positions at each baseball field to allow for consistent measurement of kinematic parameters. The first fastball of each inning was recorded, and when applicable, the first fastball after the 15th pitch and 30th pitch of the inning were also recorded. Filming commenced with the first pitch of the game and was completed when the pitcher’s performance was done. Data such as pitch count, duration of each inning, duration of rest between innings, and pitch velocity were recorded. After the game, each pitcher completed a questionnaire rating subjective measures of fatigue. Data included a binary self-assessment of the pitcher’s ability to continue pitching and a rating of the degree of fatigue felt at the beginning and at the end of the game. Fatigue was quantified using a 10-point visual analog scale, with the player marking his level of energy on a 10-cm line between “completely fatigued” and “fully rested.”

Bottom Line: Maximum external rotation of the shoulder and elbow height at foot contact decreased over the course of a game.Elbow flexion decreased with greater season pitch counts.Recognition of kinematic alterations may better demonstrate fatigue-related injury risk and may assist injury prevention in addition to standardized limitations of innings and pitches thrown.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Columbia University Medical Center, New York, New York, USA. ; Department of Orthopaedic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA.

ABSTRACT

Background: Many factors are believed to contribute to throwing injuries in baseball pitchers, in particular overuse and poor throwing mechanics. The impact of fatigue on pitching biomechanics in live-game situations is not well understood.

Hypothesis: Pitchers will demonstrate significant deviation in their pitching motions with increasing levels of fatigue.

Study design: Descriptive laboratory study.

Methods: Eleven National Collegiate Athletic Association (NCAA) Division I collegiate baseball pitchers were filmed in multiple live-game situations throughout a single season using 2 orthogonal high-speed cameras at 120 Hz. The first fastball of each inning and, when available, the fastball subsequent to the 15th and 30th pitch of each inning were recorded and analyzed for 26 kinematic parameters. Pitch count and velocity were recorded. Kinematic differences were assessed for association with pitch count and subjective fatigue measures over the course of each inning and game through the season.

Results: Twenty-six games were recorded. Pitchers had a mean of 97.2 ± 16.1 pitches per start and 1079 ± 251 pitches per collegiate season. Increased hip lean at hand separation, elbow height at foot contact, and hip flexion and shoulder tilt at maximum external rotation were seen in innings lasting longer than 15 pitches. Maximum external rotation of the shoulder and elbow height at foot contact decreased over the course of a game. Hip lean at hand separation and elbow height at foot contact increased over the course of the season. Season pitch count was weakly correlated with increased shoulder external rotation and shoulder alignment at maximum external rotation and with shoulder abduction at ball release. Elbow flexion decreased with greater season pitch counts.

Conclusion: Hip lean, elbow height, and shoulder external rotation were the most sensitive kinematic parameters to inning, game, and season fatigue. Pitch count and fatigue have a significant impact on live-game pitching kinematics.

Clinical relevance: Fatigue likely alters pitching mechanics. Recognition of kinematic alterations may better demonstrate fatigue-related injury risk and may assist injury prevention in addition to standardized limitations of innings and pitches thrown.

No MeSH data available.


Related in: MedlinePlus