Study finds technique may be a factor among young athletes
“Approximately half of all young pitchers will experience elbow and shoulder pain over the course of a season,” reported Cynthia R. LaBella, MD, at the 2011 annual meeting of the Pediatric Orthopaedic Society of North America. Although a number of factors have been associated with pain (Table 1), most prevention efforts have focused on limiting pitch count and pitch types. Dr. LaBella’s research used three-dimensional motion analysis to examine the relationship between pitching technique and pain.
Researchers recruited 56 male baseball pitchers, 11 to 15 years old, from Chicago community baseball leagues. All participants were Tanner stage 2 or 3 (self-assessed) and had pitched an average of one game a week and two or more innings per game for the previous 2 years. None of the participants had a history of pain, injury, or surgery in the elbow or the shoulder of his throwing arm or any chronic orthopaedic, musculoskeletal, or neuromuscular conditions.
The pitchers were evaluated in motion center 2 to 4 weeks before the 2006 baseball season began. Reflective markers were placed on standard anatomic landmarks, and as the pitchers threw fastballs from a regulation mound, 10 cameras captured their pitching motion (Fig. 1).
During the season, players used a secure website on a weekly basis to answer the following questions:
- How many pitches did you throw in games this week?
- Did you feel any pain in your elbow from pitching?
- Did you feel any pain in your shoulder from pitching?
Pain or no pain?
Of the 56 recruits, 39 completed the study. For analysis, pitchers were divided into two groups. The “no pain” group included those who did not report pain during either the 2006 or 2007 season. The “pain” group included those who reported pain during at least 2 weeks of the 2006 season.
Thirteen kinematic variables were identified a priori by pitching experts as key factors in defining good pitching technique. Paired t-tests compared the pain group to the no-pain group for the following three variables that had the greatest difference in mean scores between groups:
- Internal shoulder rotation at initiation of external shoulder rotation in stride
- Shoulder elevation at initiation of elbow extension in stride
- Average shoulder elevation from start of pitching cycle to time of maximum shoulder elevation
“All these measures primarily occur during the stride phase of the pitching cycle,” Dr. LaBella explained, “which begins at the top of the leg lift and ends with the planting of the heel. The pain group had greater internal shoulder rotation at the initiation of external rotation in the stride.
“The pain group also had lower shoulder elevation at the initiation of elbow extension in stride. This occurs as the pitcher is separating his hands to remove the ball from the glove. Lastly, the pain group had lower average shoulder elevation from the start of the pitching cycle to the time of maximum shoulder elevation,” she explained.
Problems and potential
Dr. LaBella noted that the number of pitchers reporting pain in this study was unexpectedly small, which limited the researchers’ ability to analyze more than three kinematic variables. A larger study would be needed to examine additional kinematic variables.
Other limitations included the self-reporting of pitch counts and the fact that anthropometric and motion data were collected only at the beginning and may have changed over the study period.
On the other hand, this study is the first to provide specific information about which aspects of the pitching motion may be putting young pitchers at risk for injury. The three kinematic parameters identified as being associated with pain “are easily identified by coaches and potentially easy for young pitchers to correct,” Dr. LaBella concluded.
Dr. LaBella’s coauthors for “Pitching biomechanics associated with elbow or shoulder pain in youth baseball pitchers: A prospective cohort study” include Tasos Karakostas, MPT, PhD; Erik C.B. King, MD; and Simon M. Hsiang, PhD, PE, CPE. Funding for the study was provided by Children’s Memorial Faculty Practice Plan and the Chicago White Sox Charities.
Disclosure information: The authors report no conflicts.
- This small, prospective study used three-dimensional motion analysis to examine the relationship between pitching technique and pain among a group of young male baseball pitchers.
- Pitchers who self-reported pain during the study were found to have poorer pitching techniques, particularly during the stride phase of pitching, than those who reported no pain. (Actual reason for pain was not diagnosed.)
- In addition to standard injury prevention strategies—such as limiting pitch count and types of pitches thrown—a focus on technique may help reduce pain in young baseball pitchers.