A biomechanical analysis of youth pitching mechanics
ABSTRACT It is estimated that nearly 6% of youth baseball participants seek medical attention for injuries sustained during play. Most injuries are overuse injuries, and 26% are to the shoulder or upper arm. By quantifying youth pitching biomechanics, knowledge can be gained concerning the manner in which these injuries are sustained during play.
Sixteen healthy right hand-dominant baseball pitchers participated in this study. After digitization of 21 bony landmarks, kinematic calculations were conducted using the 3-dimensional coordinates from each video frame. Data were time normalized, forcing major temporal components of the movement to occur at specific intervals. Segment-based reference frames were established, and resultant joint kinetics were projected onto each reference frame. Kinetic data were normalized and calculated along or about the anterior/posterior, medial/lateral, and proximal/distal axes.
Maximum trunk rotation and external shoulder rotation were observed during arm cocking. Each of the remaining kinematic parameters peaked after ball release. All maximum values for joint kinetics were measured during arm cocking with the exception of compressive forces experienced at the shoulder and elbow, which peaked after the instant of ball release.
Data produced in this study indicate that youth pitchers initiate trunk rotation early in the movement, which can lead to shoulder hyperangulation. Opposing torques at each end of the humerus also produce a large net torque about the longitudinal axis of the humerus during late arm cocking and may increase humeral retrotorsion in youth pitchers. Underdeveloped musculature in the rotator cuff may lead to difficulty controlling throwing-arm deceleration, causing an increase in horizontal adduction across the torso.
An improved understanding of youth pitching mechanics is gained from the data collected, analyzed, and discussed in this study. Through increases in the knowledge pertaining specifically to the mechanics of youth pitchers, the opportunity to develop pitching mechanics specifically designed for preventing injuries in little league pitchers arises.
This study is a Level 4 study describing youth pitching biomechanics and how they relate to possible injuries.
- SourceAvailable from: Hillary Plummer
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- "The kinematics and kinetics of baseball pitching have been well documented (Dapena, 1978; Escamilla, Fleisig, Barrentine, Zheng, & Andrews, 1998; Feltner & Dapena, 1986; Fleisig, Andrews, Dillman, & Escamilla, 1996; Fleisig, Escamilla, Andrews, Matsuo, Satterwhite et al., 1996; Keeley, Hackett, Keirns, Sabick, & Torry, 2008) while those of softball are beginning to evolve (Oliver, Dwelly, & Kwon, 2010; Oliver & Plummer, 2011; Rojas, Provencher, Bhatia, Foucher, Bach et al., 2009; Werner, Gill, Murray, Cook, & Hawkins, 2001; Werner, Guido, McNeice, Richardson, Delude et al., 2005; Werner, Jones, Guido, & Brunet, 2006). The great interest in baseball pitching is that it is the most dynamic human movement thus placing the upper extremity at increased risk of injury (Fleisig, Barrentine, Escamilla, & Andrews, 1996). "
ABSTRACT: Abstract The catcher has the most demanding position in the games of baseball and softball with no regulations on how many throws they make during game. It was the purpose of this study to describe the kinematics and kinetics of the throwing motion in catchers when throwing down to second base. It was hypothesised that younger and older catchers would display significantly different throwing kinematics and kinetics. Thirty-eight baseball and softball catchers volunteered to participate. Twenty participants were considered younger (aged 9-14, 10.95 ± 1.76 years, 151.11 ± 15.64 cm, 47.94 ± 18.84 kg) and 18 were deemed the older group (aged 15-23, 18.11 ± 2.61 years, 170.91 ± 8.67 cm, 74.88 ± 10.74 kg). Participants received a pitch and completed five accurate throws to second base in full catching gear. The average ball speed of the older catchers was 21 ± 3.58 meters per second (47 ± 8.02 mph) while the younger catchers averaged 17.2 ± 4.0 meters per second (38.6 ± 8.96 mph). Older catchers had greater shoulder elevation at ball release and significantly greater shoulder external rotation at foot contact and shoulder maximum external rotation than younger catchers. It is clear that chronological age plays a role in the throwing mechanics observed in catchers throwing down to second base, however the effects of these differences are not fully understood (i.e., skeletal maturity, experience, strength).Journal of Sports Sciences 02/2013; DOI:10.1080/02640414.2013.770907 · 2.10 Impact Factor
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- "Body segment masses and inertial parameters were obtained from previous literature and scaled to participant height and mass (Clauser et al., 1969; Hinrichs, 1990). Shoulder anterior force was defined as the anterior component of the resultant force acting along the anterior/posterior axis of the shoulder, while shoulder proximal force was defined as the component of the resultant force acting along the longitudinal axis of the shoulder (Keeley et al., 2008; Sabick et al., 2004a; Sabick et al., 2004b). Each of these forces was modeled using a convention that calculated the force applied by the torso to the proximal humerus and were normalized to percent bodyweight. "
ABSTRACT: Previous work has postulated that shoulder pain may be associated with increases in both peak shoulder anterior force and peak shoulder proximal force. Unfortunately these relationships have yet to be quantified. Thus, the purpose of this study was to associate these kinetic values with reported shoulder pain in youth baseball pitchers. Nineteen healthy baseball pitchers participated in this study. Segment based reference systems and established calculations were utilized to identify peak shoulder anterior force and peak shoulder proximal force. A medical history questionnaire was utilized to identify shoulder pain. Following collection of these data, the strength of the relationships between both peak shoulder anterior force and peak shoulder proximal force and shoulder pain were analyzed. Although peak anterior force was not significantly correlated to shoulder pain, peak proximal force was. These results lead to the development of a single variable logistic regression model able to accurately predict 84.2% of all cases and 71.4% of shoulder pain cases. This model indicated that for every 1 N increase in peak proximal force, there was a corresponding 4.6% increase in the likelihood of shoulder pain. The magnitude of peak proximal force is both correlated to reported shoulder pain and capable of being used to accurately predict the likelihood of experiencing shoulder pain. It appears that those pitchers exhibiting high magnitudes of peak proximal force are significantly more likely to report experiencing shoulder pain than those who generate lower magnitudes of peak proximal force.Journal of Human Kinetics 10/2012; 34(1):15-20. DOI:10.2478/v10078-012-0059-8 · 0.70 Impact Factor
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ABSTRACT: Baseball is a very popular and safe sport for children and adolescents. Understanding bone maturation and risk factors for overuse will guide the practitioner to manage these athletes properly. Overuse injury risk can be minimized by limiting pitch counts, ensuring adequate recovery, developing proper mechanics, and allowing for early evaluation and intervention. Rest, albeit difficult for the athlete, is the mainstay of treatment for many of the maladies affecting this age group of throwers. Individualized approaches to treatment for this population are advised. Structural damage that may lead to surgery is rare but may need consideration if there is no response to conservative measures. Several resources are available to educate players, coaches, and parents regarding safe play.Current Sports Medicine Reports 9(5):294-8. DOI:10.1249/JSR.0b013e3181f27403 · 1.60 Impact Factor