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Surface Electromyography of the Forearm Musculature During the Windmill Softball Pitch.

Remaley DT, Fincham B, McCullough B, Davis K, Nofsinger C, Armstrong C, Stausmire JM - Orthop J Sports Med (2015)

Bottom Line: The flexor carpi ulnaris signal strength was significantly greater than the other forearm flexors.Understanding the mechanics and physiology of the elbow in windmill pitchers is crucial to prevention and treatment of these increasingly common elbow injuries.This study establishes baseline data that will be useful to further prevent windmill pitch elbow injury.

View Article: PubMed Central - PubMed

Affiliation: Mercy St Vincent Medical Center, Toledo, Ohio, USA.

ABSTRACT

Background: Previous studies investigating the windmill softball pitch have focused primarily on shoulder musculature and function, collecting limited data on elbow and forearm musculature. Little information is available in the literature regarding the forearm. This study documents forearm muscle electromyographic (EMG) activity that has not been previously published.

Purpose: Elbow and upper extremity overuse injuries are on the rise in fast-pitch softball pitchers. This study attempts to describe forearm muscle activity in softball pitchers during the windmill softball pitch. Overuse injuries can be prevented if a better understanding of mechanics is defined.

Study design: Descriptive laboratory study.

Methods: Surface EMG and high-speed videography was used to study forearm muscle activation patterns during the windmill softball pitch on 10 female collegiate-level pitchers. Maximum voluntary isometric contraction of each muscle was used as a normalizing value. Each subject was tested during a single laboratory session per pitcher. Data included peak muscle activation, average muscle activation, and time to peak activation for 6 pitch types: fastball, changeup, riseball, curveball, screwball, and dropball.

Results: During the first 4 phases, muscle activity (seen as signal strength on the EMG recordings) was limited and static in nature. The greatest activation occurred in phases 5 and 6, with increased signal strength, evidence of stretch-shortening cycle, and different muscle characteristics with each pitch style. These 2 phases of the windmill pitch are where the arm is placed in the 6 o'clock position and then at release of the ball. The flexor carpi ulnaris signal strength was significantly greater than the other forearm flexors. Timing of phases 1 through 5 was successively shorter for each pitch. There was a secondary pattern of activation in the flexor carpi ulnaris in phase 4 for all pitches except the fastball and riseball.

Conclusion: During the 6 pitches, the greatest muscular activity was in phases 5 and 6. Flexor carpi ulnaris activity was greatest among the muscles tested. The riseball had the highest peak activity, but the curveball and dropball had the highest average signal strength. This muscle activity correlates with increasing distraction in the elbow, suggesting that flexor muscles act to counterdistract the elbow as they do for the baseball pitch.

Clinical relevance: Windmill pitchers are unique among overhead athletes as they throw, on average, more pitches per overhead athlete. Understanding the mechanics and physiology of the elbow in windmill pitchers is crucial to prevention and treatment of these increasingly common elbow injuries. This study establishes baseline data that will be useful to further prevent windmill pitch elbow injury.

No MeSH data available.


Related in: MedlinePlus

Surface electromyography chart of the changeup pitch. MVIC, maximum voluntary isometric contraction; PT, pronator teres; FCR, flexor carpi radialis; FDS, flexor digitorum superficialis; FCU, flexor carpi ulnaris.
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fig6-2325967114566796: Surface electromyography chart of the changeup pitch. MVIC, maximum voluntary isometric contraction; PT, pronator teres; FCR, flexor carpi radialis; FDS, flexor digitorum superficialis; FCU, flexor carpi ulnaris.

Mentions: Muscle activity in the forearm showed a consistent increase across the successive phases (Figures 5–10). The lowest average activity was seen in phase 3, with an average signal strength below 50% of the MVIC. The signal strength markedly increased during phases 4 through 6. Flexor carpi ulnaris (FCU) contraction reached an average of nearly 500% of MVIC during phase 6 of the riseball pitch. Pronator teres, flexor carpi radialis, and flexor digitorum superficialis also increased but with a variable pattern based on pitch type. Each of these muscles did have an increase in average peak activity to at least 150% of MVIC. The breaking pitches (dropball, curveball, screwball) had a more rapid increase in FCU activation during phase 4 that plateaued in phase 5 and then a second rapid rise in peak activity through phase 6. The riseball and fastball pitches showed a more consistent rise through phases 4 and 5, with a rapid increase through phase 6. The changeup pitch did show a decrease in pronator teres activity between phases 5 and 6.


Surface Electromyography of the Forearm Musculature During the Windmill Softball Pitch.

Remaley DT, Fincham B, McCullough B, Davis K, Nofsinger C, Armstrong C, Stausmire JM - Orthop J Sports Med (2015)

Surface electromyography chart of the changeup pitch. MVIC, maximum voluntary isometric contraction; PT, pronator teres; FCR, flexor carpi radialis; FDS, flexor digitorum superficialis; FCU, flexor carpi ulnaris.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2 - License 3
Show All Figures
getmorefigures.php?uid=PMC4555585&req=5

fig6-2325967114566796: Surface electromyography chart of the changeup pitch. MVIC, maximum voluntary isometric contraction; PT, pronator teres; FCR, flexor carpi radialis; FDS, flexor digitorum superficialis; FCU, flexor carpi ulnaris.
Mentions: Muscle activity in the forearm showed a consistent increase across the successive phases (Figures 5–10). The lowest average activity was seen in phase 3, with an average signal strength below 50% of the MVIC. The signal strength markedly increased during phases 4 through 6. Flexor carpi ulnaris (FCU) contraction reached an average of nearly 500% of MVIC during phase 6 of the riseball pitch. Pronator teres, flexor carpi radialis, and flexor digitorum superficialis also increased but with a variable pattern based on pitch type. Each of these muscles did have an increase in average peak activity to at least 150% of MVIC. The breaking pitches (dropball, curveball, screwball) had a more rapid increase in FCU activation during phase 4 that plateaued in phase 5 and then a second rapid rise in peak activity through phase 6. The riseball and fastball pitches showed a more consistent rise through phases 4 and 5, with a rapid increase through phase 6. The changeup pitch did show a decrease in pronator teres activity between phases 5 and 6.

Bottom Line: The flexor carpi ulnaris signal strength was significantly greater than the other forearm flexors.Understanding the mechanics and physiology of the elbow in windmill pitchers is crucial to prevention and treatment of these increasingly common elbow injuries.This study establishes baseline data that will be useful to further prevent windmill pitch elbow injury.

View Article: PubMed Central - PubMed

Affiliation: Mercy St Vincent Medical Center, Toledo, Ohio, USA.

ABSTRACT

Background: Previous studies investigating the windmill softball pitch have focused primarily on shoulder musculature and function, collecting limited data on elbow and forearm musculature. Little information is available in the literature regarding the forearm. This study documents forearm muscle electromyographic (EMG) activity that has not been previously published.

Purpose: Elbow and upper extremity overuse injuries are on the rise in fast-pitch softball pitchers. This study attempts to describe forearm muscle activity in softball pitchers during the windmill softball pitch. Overuse injuries can be prevented if a better understanding of mechanics is defined.

Study design: Descriptive laboratory study.

Methods: Surface EMG and high-speed videography was used to study forearm muscle activation patterns during the windmill softball pitch on 10 female collegiate-level pitchers. Maximum voluntary isometric contraction of each muscle was used as a normalizing value. Each subject was tested during a single laboratory session per pitcher. Data included peak muscle activation, average muscle activation, and time to peak activation for 6 pitch types: fastball, changeup, riseball, curveball, screwball, and dropball.

Results: During the first 4 phases, muscle activity (seen as signal strength on the EMG recordings) was limited and static in nature. The greatest activation occurred in phases 5 and 6, with increased signal strength, evidence of stretch-shortening cycle, and different muscle characteristics with each pitch style. These 2 phases of the windmill pitch are where the arm is placed in the 6 o'clock position and then at release of the ball. The flexor carpi ulnaris signal strength was significantly greater than the other forearm flexors. Timing of phases 1 through 5 was successively shorter for each pitch. There was a secondary pattern of activation in the flexor carpi ulnaris in phase 4 for all pitches except the fastball and riseball.

Conclusion: During the 6 pitches, the greatest muscular activity was in phases 5 and 6. Flexor carpi ulnaris activity was greatest among the muscles tested. The riseball had the highest peak activity, but the curveball and dropball had the highest average signal strength. This muscle activity correlates with increasing distraction in the elbow, suggesting that flexor muscles act to counterdistract the elbow as they do for the baseball pitch.

Clinical relevance: Windmill pitchers are unique among overhead athletes as they throw, on average, more pitches per overhead athlete. Understanding the mechanics and physiology of the elbow in windmill pitchers is crucial to prevention and treatment of these increasingly common elbow injuries. This study establishes baseline data that will be useful to further prevent windmill pitch elbow injury.

No MeSH data available.


Related in: MedlinePlus