Changes
in humeral torsion and shoulder rotation range of motion in high school
baseball players over a 1-year period
in humeral torsion and shoulder rotation range of motion in high school
baseball players over a 1-year period
Oyama S, Hibberd EE, Myers JB. Clin Biomech
(Bristol, Avon). 2013 Feb 19. pii: S0268-0033(13)00015-6. doi:
10.1016/j.clinbiomech.2013.01.014. [Epub ahead of print]
(Bristol, Avon). 2013 Feb 19. pii: S0268-0033(13)00015-6. doi:
10.1016/j.clinbiomech.2013.01.014. [Epub ahead of print]
Take Home
Message: Over one year, high school baseball players had no bony changes (humeral
retroversion) in their dominant arm’s humerus but had decreased shoulder
internal rotation.
Message: Over one year, high school baseball players had no bony changes (humeral
retroversion) in their dominant arm’s humerus but had decreased shoulder
internal rotation.
Unilateral overhead sports cause several bony and
soft tissue adaptations on the dominant arm due to the large amounts of
mechanical stress. However, it is
unknown when bony adaptations (e.g., humeral retroversion) occur during
skeletal development. Therefore, the
authors examined the longitudinal change of humeral retroversion and
glenohumeral range of motion in 138 high school baseball players between the
start of 2 consecutive seasons.
Participants also completed a history questionnaire indicating the
number of years they participated in baseball.
Players were excluded if they had a current injury or an injury within
the past year. The authors used an
ultrasound technique to measures humeral retroversion and standard procedures
(inclinometer) to measure glenohumeral range of motion. The authors found that humeral retroversion
did not change over a 1 year period regardless of the amount of years
participating in baseball. Dominant arm
internal rotation decreased over the 1 year period but was not affected by the
amount of years participating in baseball.
External rotation and total range of motion decreased bilaterally over
the 1 year period among participants that only played baseball for 1 year
prior.
soft tissue adaptations on the dominant arm due to the large amounts of
mechanical stress. However, it is
unknown when bony adaptations (e.g., humeral retroversion) occur during
skeletal development. Therefore, the
authors examined the longitudinal change of humeral retroversion and
glenohumeral range of motion in 138 high school baseball players between the
start of 2 consecutive seasons.
Participants also completed a history questionnaire indicating the
number of years they participated in baseball.
Players were excluded if they had a current injury or an injury within
the past year. The authors used an
ultrasound technique to measures humeral retroversion and standard procedures
(inclinometer) to measure glenohumeral range of motion. The authors found that humeral retroversion
did not change over a 1 year period regardless of the amount of years
participating in baseball. Dominant arm
internal rotation decreased over the 1 year period but was not affected by the
amount of years participating in baseball.
External rotation and total range of motion decreased bilaterally over
the 1 year period among participants that only played baseball for 1 year
prior.
This study found that bony adaptation of humeral
retroversion may be complete prior to high school. This suggests that we need to examine younger
adolescents to identify when this bony adaptation is occurring and how quickly
it is occurs In addition, this study
used a simple ultrasound method to measure humeral retroversion, which can be
implemented clinically if a diagnostic ultrasound is present. The authors also found that dominant arm
internal rotation decreased over the one year period. This is in agreement with a previous study that examined female high school overhead athletes. This may suggest
that the deceleration stress caused during the throwing motion contributes to
posterior shoulder soft tissue tightness.
Previous research has linked decreases in internal rotation to shoulder
injuries and internal impingement. Lastly, the authors found that external
rotation and total range of motion to decreased bilaterally but only in players
that only played the year prior. This is
an interesting finding and may suggest that there is a soft tissue reaction to
the new stress placed on the shoulder joint among players that just started to
play. It would be interesting if this is
only seen during the first year of participation and it resolves itself in
time. Clinically, these results
demonstrate the importance of examining players longitudinally. It suggests that if changes in range of
motion are detected longitudinally in high school baseball players then the
changes are indicative of soft tissue tightness and stretching should probably be
implemented to reduce the risk of future shoulder injuries. Do you examine glenohumeral range of motion
over the season in your overhead athletes?
What information do you use to identify the players that need to be
stretched?
retroversion may be complete prior to high school. This suggests that we need to examine younger
adolescents to identify when this bony adaptation is occurring and how quickly
it is occurs In addition, this study
used a simple ultrasound method to measure humeral retroversion, which can be
implemented clinically if a diagnostic ultrasound is present. The authors also found that dominant arm
internal rotation decreased over the one year period. This is in agreement with a previous study that examined female high school overhead athletes. This may suggest
that the deceleration stress caused during the throwing motion contributes to
posterior shoulder soft tissue tightness.
Previous research has linked decreases in internal rotation to shoulder
injuries and internal impingement. Lastly, the authors found that external
rotation and total range of motion to decreased bilaterally but only in players
that only played the year prior. This is
an interesting finding and may suggest that there is a soft tissue reaction to
the new stress placed on the shoulder joint among players that just started to
play. It would be interesting if this is
only seen during the first year of participation and it resolves itself in
time. Clinically, these results
demonstrate the importance of examining players longitudinally. It suggests that if changes in range of
motion are detected longitudinally in high school baseball players then the
changes are indicative of soft tissue tightness and stretching should probably be
implemented to reduce the risk of future shoulder injuries. Do you examine glenohumeral range of motion
over the season in your overhead athletes?
What information do you use to identify the players that need to be
stretched?
Written by:
Stephen Thomas
Stephen Thomas
Reviewed by: Jeffrey Driban
Related Posts:
Oyama S, Hibberd EE, & Myers JB (2013). Changes in humeral torsion and shoulder rotation range of motion in high school baseball players over a 1-year period. Clinical Biomechanics (Bristol, Avon) PMID: 23434341
Were there high school freshmen on the teams as well? Could the bony adaptations in the arm be something that has to occur before puberty? You have also stated that the internal rotation of the dominant arm decreases over the year, were these athletes stretching and being stretched out everyday? If not do you believe that them being passively stretched and actively stretching their Glenohumeral joint would help to keep or increase their internal rotation?
Thank you
Kaitlyn thanks for the comment. The study included all levels of high school baseball players. What is your concern about freshman? Yes this study indicated that humeral retroversion clearly is occurring prior to high school. We need to start looking at even younger groups. It did not indicate if players were engaging in their own stretching programs. One might assume that stretching would prevent that decrease however the research is lacking long term stretching protocols on range of motion.
Based on this study, do you think this decrease in IR and ER will lead to scapular dyskinesis?
Will good question. We current don't know if glenohumeral internal rotation deficits (GIRD) cause scapular dyskinesis. It truly is the chicken or egg situation. I published a paper that found there was an association between the two (https://www.ncbi.nlm.nih.gov/pubmed/19841995). Specifically we found players with larger amounts of GIRD also had scapular dyskinesis. However, this doesn't demonstrate cause and effect.