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Is GIRD in Asymptomatic Athletes a Risk Factor for Shoulder Injury? - A prospective collegiate study at Kean University. Nicholas Belasco DO. What Goes Up Must Come Down. Tremendous force on the arm during throwing: Late cocking through acceleration Leads to Capsular Damage: Stretching
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Is GIRD in Asymptomatic Athletes a Risk Factor for Shoulder Injury?- A prospective collegiate study at Kean University Nicholas Belasco DO
What Goes Up Must Come Down • Tremendous force on the arm during throwing: Late cocking through acceleration • Leads to Capsular Damage: • Stretching • Contractures • Labral Damage: • SLAP Lesions • We see this in all overhead athletes: • Tennis • Baseball • Volleyball • Swimmers
Historical Perspective • Very Controversial – “dead arm syndrome” • Andrews et al. AJSM – 1985 • Postulates that the deceleration phase of throwing causes the injuries • Jobe et al. J Shoulder/Elbow Surg – 1995 • Internal impingement issue caused by/related to capsular laxity in ant capsule • Burkhart et al. Arthroscopy – 1998 • “peel-back” lesion: leading to capsular contractures • Really unknown what was causing all these shoulders to fail
Trying to Explain Injury: The Thrower’s Paradox • The overhead athlete’s shoulder must be: • Lax enough to allow excessive external rotation to accommodate power generation • Stable enough to prevent injury
Shoulder ROM Adaptations • Athletes gain ER at expense of IR • Physiologic adaptation to maintain the 180 degree arc • Humeral head retroversion additional adaptation • Asymptomatic pitchers have more humeral retroversion
The Effect of GIRD: • As arthroscopy becomes more common place SLAP lesions are discovered more easily (esp type 2) • Numerous research papers showing a retrospective correlation between painful shoulders/SLAP tears/restricted posterior capsule etc. and existence of GIRD
The Effect of GIRD: • Why does GIRD = SLAP? • Thought to be due to increased posterior/superior instability secondary to posterior/inferior capsule contraction • Grossman et al. JBJS 2005 • Concluded that a shift posterior/inferior of the capsule forces the humeral head posterior/superior which could explain the etiology of SLAP lesions
GIRD Defined • Internal rotation reduction accompanies external rotation increase • GIRD- • According to Burkhart et al. (Burkhart et al., 2003b),GIRD is “the loss in degrees of glenohumeral internal rotation of the throwing shoulder compared with the non-throwing shoulder”. • an internal rotation loss that exceeds the external rotation gain in the dominant arm (“true” GIRD) • a loss of internal rotation with a loss of total arc of motion in the pitching arm • a loss of greater than 25° of internal rotation
Is all GIRD Bad? • Asymptomatic vs. Symptomatic? • “true” GIRD vs. “false” GIRD? • The answer lays with prospective study • Identify risk factors and modifiers • This is a true prevention model
First Prospective Studies • Donley et al. 1999-2002 • Rotational data on 430 professional pitchers • Compared GIRD with injury data and on field performance data • Found GIRD of 10-12 degrees optimal for eliminating shoulder injury • Clear need to reproduce and expand on this investigational data
Is GIRD in Asymptomatic Athletes a Risk Factor for Shoulder Injury? • A prospective study to evaluate a number of factors related to GIRD in asymptomatic collegiate athletes: • Baseball/Volleyball/Softball • Questions: • Role of degree of GIRD on injury risk • Role of Rate of Change on injury risk • Role of “False” vs. “True” GIRD
Methods • Athletes from Kean University (Div III) Volleyball, Baseball and Softball teams (~60 participants) • Athletes answered survey during pre-season and post-season • Demographics • Shoulder injury history • Athletic participation history • Penn shoulder scores for: • Pain • Function • Satisfaction
Methods • Clinical measures taken during pre-season and repeated post-season • Validated method chosen after literature search • All exams preformed by same team physician and ATCs • Bilateral measures taken of both IR and ER • Athlete lays with shoulder stabilized and is passively moved into internal and external rotation • -Measure taken when motion at scapula felt by examiner • -Measures are in (+) degrees away from 90 degrees (the 0 point)
Pre-season Data • Of 13 Volleyball players: • 5 had mild symptoms at rest • All athletes had some degree of GIRD (total rotation deficit) • Not related to years playing, age, shoulder symptom score
Post-Season Data • On-going study: • Volleyball arm complete • No injuries during season but symptomatic changes seen in Penn Shoulder Score • Not statistically significant • Development of symptoms appears unrelated to degree of GIRD or rate of change • Participants had an increase in external rotation without corresponding change in internal rotation that was statistically significant
A total of 13 right-arm female volleyball players were included in the study, with average age of 19 years [SD = 0.71]. Distribution of race was: 69% White, 23% Hispanic and 8% Asian. Average experience was 7.2 years [SD = 2.03]. Two players (15%) had history of injury and none of the players (0%) had any history of surgery. The results in Table 1 showed statistically significant difference between pre season and post-season in terms of ROM External – right [average Rom External – right was 94.44 pre-season vs. 105.00 post-season; p = 0.009] and ROM Total – right [average ROM Total – right was 134.33 pre-season vs. 145.56 post-season; p = 0.011]. No statistically significant difference was observed between pre season and post-season in terms of any of the other measures listed in the table (p >0.05).
Discussion • Tremendous variability in degree of pre-season ROM with large ranges and large standard deviation • Confirms that using GIRD as sole marker of shoulder dysfunction is at best speculative • Many athletes had clinically defined GIRD without progression to symptoms • Much greater number then previously thought • Should all these athletes be put on aggressive stretching programs?
Discussion • Subset of “true” GIRD deserves greater focus • Working to consensus of the definition of GIRD should be based on clinical consensus of pathological impact Each new study on asymptomatic athletes highlights these same problems
Conclusion • Study must run to completion • Initial results should impact treatment • Without clear and modifiable risk factors – primary prevention cannot be undertaken • Therapy programs designed to reduce GIRD do work (to reduce GIRD) effect on outcomes less certain