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”.
1. an internal rotation loss that exceeds the
external rotation gain in the dominant arm (“true”
GIRD)
2. a loss of internal rotation with a loss of total arc of
motion in the pitching arm
3. 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 preseason and post-season
• Demographics
• Shoulder injury history
• Athletic participation history
• Penn shoulder scores for:
• Pain
• Function
• Satisfaction
Methods
-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)
• 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
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
Pre-Season
Post-Season
p-value*
N
Mean
SD
N
Mean
SD
ROM Internal - Left
9
49.44
9.95
9
49.33
4.95
0.97
ROM External - Left
9
90.78
15.56
9
93.33
14.19
0.62
ROM Total - Left
9
140.22
10.71
9
142.67
12.67
0.61
ROM Internal - Right
9
39.89
7.66
9
40.56
4.85
0.81
ROM External - Right
9
94.44
10.98
9
105.00
12.60
0.009
ROM Total - Right
9
134.33
6.40
9
145.56
13.45
0.011
Penn Score - Pain
9
29.67
0.71
9
29.89
0.33
0.45
Penn Score - Function
9
59.56
0.73
9
59.56
0.73
1.00
•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 postseason 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 postseason; p = 0.011].
No statistically significant
difference was observed
between pre season and postseason 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