San Diego, CA—March 14, 2017
Elbow injuries continue to be on the rise in baseball players, especially pitchers, yet little is known about the actual variables that influence these injuries.
While elbow varus torque is already linked to ulnar collateral ligament (UCL) injuries, the connection between certain pitching movements and elbow varus torque is unknown.
A recent study from Hospital for Special Surgery set out to find the relationship between elbow varus torque and the following variables: arm slot, arm speed and shoulder rotation. The prospective cohort study looked at 81 professional pitchers (either in the Major or Minor Leagues) who took 81,999 throws while wearing a Motus baseball sleeve.
These were a combination of throws that were evaluated in real settings such as structured long tosses and live game play, as opposed to in a laboratory like previous studies. This was the largest analysis of throwing biomechanics to date.
"Obtaining this comprehensive, individualized analysis of on-field throwing activity was made possible by technological advancements that give us the ability to accurately measure body motions outside the lab," said Joshua Dines, MD, sports medicine surgeon at HSS and primary investigator. "Capturing data during the pitchers’ normal activities provided us with robust, baseline biomechanical performance metrics."
The study found that arm slot, arm speed and shoulder rotation all have a significant relationship with elbow varus torque. There was a 1-nm increase in elbow varus torque associated with a 13 degree decrease in arm slot, 116% increase in arm speed and 8 degree increase in shoulder rotation.
Increased arm speed and shoulder rotation were found to be associated with increased elbow stress as well as decreased arm slot. Height and weight were also positively correlated with elbow varus torque.
"Now that we know these modifiable risk factors, we have a foundation to develop evidence-based rehabilitation programs. Additionally, these findings can be utilized to prevent injury and help to identify potential pitchers at risk," said David Altchek, MD, sports medicine surgeon at HSS.
HSS Clinical fellow Christopher Camp, MD, also was an author on the study.
This poster was presented today at this year’s annual meeting for The American Academy of Orthopaedic Surgeons (AAOS).
About HSS | Hospital for Special Surgery
HSS is the world’s leading academic medical center focused on musculoskeletal health. At its core is Hospital for Special Surgery, nationally ranked No. 1 in orthopedics (for the ninth consecutive year) and No. 3 in rheumatology by U.S.News & World Report (2018-2019). Founded in 1863, the Hospital has one of the lowest infection rates in the country and was the first in New York State to receive Magnet Recognition for Excellence in Nursing Service from the American Nurses Credentialing Center four consecutive times. The global standard total knee replacement was developed at HSS in 1969. An affiliate of Weill Cornell Medical College, HSS has a main campus in New York City and facilities in New Jersey, Connecticut and in the Long Island and Westchester County regions of New York State. In 2017 HSS provided care to 135,000 patients and performed more than 32,000 surgical procedures. People from all 50 U.S. states and 80 countries travelled to receive care at HSS. In addition to patient care, HSS leads the field in research, innovation and education. The HSS Research Institute comprises 20 laboratories and 300 staff members focused on leading the advancement of musculoskeletal health through prevention of degeneration, tissue repair and tissue regeneration. The HSS Global Innovation Institute was formed in 2016 to realize the potential of new drugs, therapeutics and devices. The culture of innovation is accelerating at HSS as 130 new idea submissions were made to the Global Innovation Institute in 2017 (almost 3x the submissions in 2015). The HSS Education Institute is the world’s leading provider of education on the topic of musculoskeletal health, with its online learning platform offering more than 600 courses to more than 21,000 medical professional members worldwide. Through HSS Global Ventures, the institution is collaborating with medical centers and other organizations to advance the quality and value of musculoskeletal care and to make world-class HSS care more widely accessible nationally and internationally.