The American Journal of Sports
Medicine
http://ajs.sagepub.com/
The Development and Validation of a Functional Assessment Tool for the Upper Extremity in the
Overhead Athlete
Frank G. Alberta, Neal S. ElAttrache, Scott Bissell, Karen Mohr, Jason Browdy, Lewis Yocum and Frank Jobe
Am J Sports Med 2010 38: 903 originally published online March 24, 2010
DOI: 10.1177/0363546509355642
The online version of this article can be found at:
http://ajs.sagepub.com/content/38/5/903
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The Development and Validation of
a Functional Assessment Tool for the Upper
Extremity in the Overhead Athlete
*yz MD, Neal S. ElAttrache,y MD, Scott Bissell,y§ MD, Karen Mohr,y PT,
Frank G. Alberta,
y
Jason Browdy, || MD, Lewis Yocum,y MD, and Frank Jobe,y MD
From yKerlan-Jobe Orthopaedic Clinic, Los Angeles, California, zHackensack University Medical
Center, Hackensack, New Jersey, §Sports Medicine Partners, Orthopedics and Rehabilitation
Therapy PC, South Windsor, Connecticut, and ||Advanced Orthopaedics of Clayton,
St Louis, Missouri
Background: There are no validated upper extremity instruments designed specifically to evaluate the performance and function
of overhead athletes. Current shoulder and elbow scoring systems may not be sensitive to subtle changes in performance in this
high-demand population.
Hypothesis: The scoring system developed in this study will be valid, reliable, and responsive in the evaluation of overhead
athletes.
Study Design: Cross-sectional study; Level of evidence, 3.
Methods: Based on the results of a pilot questionnaire administered to 21 overhead athletes, a final 10-item questionnaire was
developed. Two hundred eighty-two healthy, competitive overhead athletes completed the new questionnaire, as well as 2 established upper extremity questionnaires, and were self-assigned into injury categories: (1) playing without pain, (2) playing
with pain, and (3) not playing due to pain. Correlations between the scores and differences between injury categories were measured. Responsiveness testing was performed in an additional group of 55 injured athletes, comparing their scores before and
after an intervention.
Results: The new score showed high correlation with the Disabilities of the Arm, Shoulder and Hand (DASH) score and the DASH
sports/performing arts module. The new score correctly stratified overhead athletes by injury category (P \ .0001). The new score
also demonstrated excellent responsiveness, varying appropriately with improvements in injury category after treatment of injuries (P \ .05).
Conclusion: The new patient-reported instrument is valid and responsive in the evaluation of overhead athletes. Reliability was
also demonstrated for the 13-item pilot questionnaire. The results support its use for the functional assessment of overhead athletes in future studies.
Keywords: sports medicine; arthroscopy; upper extremity; assessment; score; overhead
of daily living and only notice their injury or manifest
symptoms during competition.
Currently, there are no validated instruments that are
designed to measure the functional status of the upper
extremity in the overhead athlete. Recently, validated
instruments for use in outcomes research have become
more widely used.6,10,12,14,19 A number of specific shoulder
and elbow measurement tools exist.1,3,8,9,13,15-18,21 Only the
Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire evaluates the entire upper extremity. However,
it is not specific to the shoulder or elbow. It remains difficult to evaluate treatment outcomes within this group. In
the past, the standard for evaluating the outcome of the
overhead athlete (specifically, baseball players) has been
the ability to return to the same level of competition for
Overhead athletes place high demands on their upper
extremities during training and competition. Injuries to
the shoulder and elbow are very common in this group of
athletes. Many of these athletes continue to compete effectively despite their injuries. It has been our experience
that these athletes may have no limitations in activities
*Address correspondence to Frank G. Alberta, MD, Hackensack University Medical Center, 30 Prospect Avenue, Hackensack, NJ 07601
(e-mail: falberta@njorthoclinic.com).
The authors declared that they had no conflicts of interest in their
authorship and publication of this contribution.
The American Journal of Sports Medicine, Vol. 38, No. 5
DOI: 10.1177/0363546509355642
Ó 2010 The Author(s)
903
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one season after rehabilitation or surgery.2 This standard
does not account for those players who changed positions,
styles, intensity, or duration of competition.
A combination of instruments may be used to measure
functional status of the shoulder and elbow. This would
require that the athlete fill out a large number of scores
that have significant overlap, which in turn, are difficult
and onerous to grade and interpret. With these difficulties
in mind, we sought to develop and validate an efficient and
reliable patient-administered questionnaire to measure
the functional status of the upper extremity in the overhead athlete. This tool would aid in the accurate assessment of overhead athletes after injury, treatment, and/or
surgery and provide a performance-based measure of outcomes in this high-demand patient population.
MATERIALS AND METHODS
Development and Validation of Initial Pilot
Questionnaire
The objective of development was a patient-athlete–administered questionnaire that requires little time to administer, is easily readable, uses visual analog scales (VASs),
and focuses on functional parameters for athletes. We
specifically excluded objective measurements from the
scope of the questionnaire. The rating system for the
athlete’s shoulder proposed by Tibone and Bradley20 was
used as background to develop the new items into a cohesive questionnaire. Potential items were gathered from
physicians, athletic trainers, and physical therapists
directly involved with the care of overhead athletes. The
authors also reviewed the literature and currently available scoring systems to evaluate questions in use as well
as generally accepted measures of outcome for the shoulder
and elbow. Instructions were given to the contributing
health care professionals to design items that were not
exclusive to any single sport and not specific to the shoulder or the elbow individually. Once all items were gathered, duplicate suggestions were removed or combined
into single questions, and an initial 13-item questionnaire
was formulated.
The questions were formatted similar to a VAS. Athletes were instructed to place a mark on a 10-cm line indicating the current level of performance and/or function of
the involved extremity; the far right represents a higher
function/level of performance. The examiner measures
the distance of the mark from the far left of the scale (representing 0) to the nearest millimeter and records it in
centimeters. For example, if an athlete’s mark is measured
as 96 mm from point 0 on the VAS, the score for this question is 9.6 of 10. Of the 13 items, 5 were very specific to
function and athletic performance (questions 6-11) and
were weighted equally to represent 50% of the total score.
The remaining 8 items measured symptoms (ie, pain,
instability, etc) related to the upper extremity (questions
1-5) or interpersonal relationships related to performance
(questions 12-13) and comprised the remaining 50%. The
senior authors determined the final weighting scheme to
be used in the pilot testing phase, with the emphasis
placed on the performance-specific measures.
Initial Questionnaire Item Screening
Twenty-one currently competing intercollegiate overhead
athletes (baseball and softball) completed a demographics
cover sheet, the DASH questionnaire, the DASH sports/
performing arts module, and the 13-item pilot questionnaire. The DASH was included in the comparison for its
excellent reliability and its inclusion of the shoulder and
elbow.1 The DASH sports/performing arts module was chosen as the only existing score designed for the athlete’s
upper extremity. On the initial pilot questionnaire, athletes were asked to rate each item for its importance to
them from 1 (least) to 5 (most) to analyze the relevance
of the individual questions as judged by the athletes
themselves.
We carried out an exploratory factor analysis (principle
components) to determine which items have a strong, positive factor loading on the first factor. In addition, we computed the Cronbach a intra-item reliability coefficient, an
average of the intra-item correlations, because the intraitem reliability should be high if an item is to be retained.
Finally, we analyzed the mean importance rating for each
item as determined by the athletes themselves.
To evaluate test-retest reliability, the athletes were
asked to fill out the same questionnaire 4 weeks later,
with the importance ratings omitted. Players who had
a significant change in their injury status as defined by
being out of competition secondary to injury were excluded
from reliability testing. The 4-week interval was chosen so
that recall of the questions was minimized, yet significant
changes in injury status were unlikely to occur. We computed the test-retest interclass correlation and the mean
test-retest differences and standard deviation (SD) of these
differences.
Questionnaire Validation
Two hundred eighty-two intercollegiate and professional
overhead athletes completed the final 10-item KerlanJobe Orthopaedic Clinic (KJOC) score questionnaire as
well as a demographic intake sheet. The demographic
data collected included sports participation and injury history. The final question on the demographic sheet asked
the athlete to assign himself/herself in 1 of 3 categories:
(1) playing with no pain, (2) playing with pain, or (3) not
playing due to pain. A confirmatory factor analysis was
carried out, and nonparametric subgroup comparisons
were made. The Kruskal-Wallis test was used to compare
median scores between sports/activity, between those
with a history of an injury and those without, between
those who were currently injured and those who were
not, between those treated for an injury and those not treated, and between the 3 injury categories listed above.
Medians were compared with nonparametric tests instead
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TABLE 1
Factor Analysis and Reliability in Screening Sample (n 5 21), 13 Items
Item
Range
Factor
Loadinga
P Value
10.0
9.2
10.0
9.2
5.3
6.1
9.1
10.0
10.0
10.0
10.0
3.6
5.7
0.762
0.727
0.579
0.939
0.567
–0.037
0.738
0.931
0.929
0.950
0.931
–0.002
0.591
\.001
.0003
.0075
\.001
.0092
.8779
.0002
\.001
\.001
\.001
\.001
.9944
.0061
1
2
3
4
5
6
7
8
9
10
11
12
13
a
Mean
Importance
(1-5 Scale)
Test-Retest
Mean Differenceb
Test-Retest
SD Differenceb
Test-Retest
Correlationb
.673
.674
.514
.895
.618
.005
.676
.909
.899
.895
.891
.034
.608
4.1
4.5
3.9
4.0
2.5
2.5
3.7
4.3
3.7
3.8
3.5
1.7
2.1
0.75
0.93
–0.37
0.62
0.02
0.24
0.12
0.35
–0.22
0.08
0.49
–0.19
0.75
1.33
1.99
3.26
1.93
2.94
1.14
1.64
2.39
1.56
1.51
2.60
1.78
1.57
0.93
0.76
0.54
0.84
–0.10
0.80
0.86
0.74
0.89
0.89
0.72
0.02
0.61
a
Correlation with the factor.
n 5 18.
b
of parametric mean comparisons because the KJOC and
DASH scores tend to have a skewed distribution.
Treatment Responsiveness
Responsiveness of the questionnaire to changes in athletic
functional status was tested using an additional group of
55 injured overhead athletes, separate from the 282 above.
Each athlete completed the KJOC questionnaire before
treatment, then underwent an intervention (rest, therapy,
and/or surgery) and was then asked to complete a posttreatment follow-up questionnaire. Demographic data
including the athlete’s self-assessment of playing category
were again collected as previously described. Median
scores or score changes were compared between groups
using the nonparametric Kruskal-Wallis test, and withingroup change P values were computed with the paired Wilcoxon signed-rank test. While the medians more appropriately show the typical value because the score distribution
may be skewed, the mean and standardized mean (Z 5
effect size 5 mean/SD) score and Z score difference are
also reported.
RESULTS
Development and Test-Retest Reliability of Initial Pilot
Questionnaire
Table 1 summarizes the factor analysis and reliability
results of the original 13 items in the 21 subjects completing the pilot questionnaire. Eighteen of the 21 subjects had
test-retest reliability data available for review. The
remaining 3 athletes had a change in their injury status
and therefore were excluded from the reliability testing.
The first factor accounted for 67% of the variation
across the 13 items. All items of the KJOC score were
positively correlated with the factor except for item 6.
Two items were weakly correlated (items 6 and 12), 2 items
were moderately correlated (items 3 and 5), and 9 items
were strongly correlated (.0.72). Items 6 and 12 were
omitted because they poorly correlate with the other items
and the composite factor and because they were of low
importance, particularly item 12. Item 12 also had poor
reliability. Item 5 was omitted because it had poor reliability, was only moderately correlated with the overall factor,
was not of high mean importance, and had a rather narrow
range. Items 3 and 13 were retained, although they only
had moderate correlation with the overall factor because,
unlike item 5, they had reasonable reliability. When in
doubt, the item was retained rather than prematurely
omitted. The factor analysis was performed again using
the remaining 10 items for both the original 21 athletes
and again on our larger dataset of 282 athletes. The factor
loadings for the larger dataset were very similar except for
items 4 and 7. Based on this and for simplicity, the final 10item questionnaire is based on an equally weighted sum of
all 10 items (Figure 1).
The unweighted 13-item KJOC score had a Pearson correlation of 0.81 with the DASH score and 0.85 with the
DASH sports/performing arts module, respectively. After
removing 1 item from each of the previously described categories (athletic performance, symptoms, interpersonal
relationships) based on the analysis above, the unweighted
10-item KJOC score had correlations of 0.84 and 0.86,
respectively, with the DASH scores. Eight of the final 10
items were strongly correlated with the factor (correlation
.0.72), while the other 2 were moderately correlated
(items 3 and 13 in Table 2).
Test-retest intraclass correlation coefficients were
higher than the DASH for both the original 13-item questionnaire and the 10-item final questionnaire (0.861 and
0.881 vs 0.835) and significantly higher than the DASH
sports/performing arts module (0.563).
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Kerlan-Jobe Orthopaedic Clinic Shoulder & Elbow Score
Name_______________________________ Age_______ Sex___________ Dominant Hand (R) ______ (L) _____ (Ambidextrous)
__________________ Date of Examination_____________________________ Sport __________ Position __________ Years Played __________
Please answer the following questions related to your history of injuries to YOUR ARM ONLY:
YES
NO
1. Is your arm currently injured?
h
h
2. Are you currently active in your sport?
h
h
3. Have you missed game or practice time in the last year due to an injury to your shoulder or elbow?
h
h
4. Have you been diagnosed with an injury to your shoulder
or elbow other than a strain or sprain?
h
h
If yes, what was the diagnosis? _______________
5. Have you received treatment for an injury to your shoulder or elbow?
If yes, what was the treatment? (Check all that apply)
h Rest h Therapy h Surgery (please describe): ___________________
h
h
h
h
h
h
h
h
Please describe your level of competition in your current sport:
(Use Professional Major League, Professional Minor League, Intercollegiate,
High School as the choices)
6. What is the highest level of competition you’ve participated at?_____________
7. What is your current level of competition? _____________________________
8. If your current level of competition is not the same as your
highest level, do you feel it is due to an injury to your arm?
Please check the ONE category only that best describes your current status:
h Playing without any arm trouble
h Playing, but with arm trouble
h Not playing due to arm trouble
Instructions to athletes:
The following questions concern your physical functioning during game and practice conditions.
Unless otherwise specified, all questions relate to your shoulder or elbow. Please answer with an
X along the horizontal line that corresponds to your current level.
1. How difficult is it for you to get loose or warm prior to competition or practice?
Normal warm-up
time
Never feel loose during
games or practice
2. How much pain do you experience in your shoulder or elbow?
Pain at rest
No pain with
competition
3. How much weakness and/or fatigue (ie, loss of strength) do you experience in your shoulder or elbow?
Weakness or
fatigue preventing
any competition
No weakness, normal
competition fatigue
4. How unstable does your shoulder or elbow feel during competition?
“Popping out”
routinely
No instability
(continued)
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Functional Assessment Tool for the Upper Extremity
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5. How much have arm problems affected your relationship with your coaches, management, and agents?
Left team, traded or
waived, lost contract
or scholarship
Not at all
The following questions refer to your level of competition in your sport. Please answer with
an X along the horizontal line that corresponds to your current level.
6. How much have you had to change your throwing motion, serve, stroke, etc, due to your arm?
Completely changed,
don’t perform motion
anymore
No change in motion
7. How much has your velocity and/or power suffered due to your arm?
Lost all power,
became finesse or
distance athlete
No change in
velocity/power
8. What limitation do you have in endurance in competition due to your arm?
Significant limitation
(became relief
pitcher, switched to
short races for
example)
No endurance limitation in
competition
9. How much has your control (of pitches, serves, strokes, etc.) suffered due to your arm?
Unpredictable control on
all pitches, serves,
strokes, etc.
No loss of control
10. How much do you feel your arm affects your current level of competition in your sport (ie, is your arm
holding you back from being at your full potential)?
Cannot compete, had
to switch sports
Desired level of
competition
Figure 1. Kerlan-Jobe Orthopaedic Clinic shoulder and elbow score.
Cross-sectional Validation of
Final Questionnaire
The final 10-item questionnaire was administered to 282
professional and intercollegiate athletes (Table 3).
Seventy-five percent (n 5 211) were baseball players, and
88% (n 5 252) were men. One hundred ninety-one athletes
were currently competing or had competed in the past at
the professional level of their sport.
A factor analysis using the 10 items confirmed that all
10 items have a strong correlation with the overall factor.
All but 2 have a correlation of 0.82 or larger. All but one
of the factor loadings were above 0.70 (item 7 is the
exception). Therefore, the final KJOC score was defined
for simplicity as the unweighted sum of the items, making
a score with a maximum value of 100.
The KJOC scores by current status category are shown
in Table 4. All cross-category comparisons revealed significant differences. Players with a history of either shoulder
or elbow injury had median KJOC scores significantly
lower than players with no history of injury (Tables 5
and 6). The KJOC scores among athletes in category 1
with a history of treatment for a shoulder or elbow injury
scored significantly lower than those with no history of
injury treatment (median, 92.0 vs 99.3; P \ .0001) (Table
7). Significant differences were found in all cross-category
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TABLE 2
Assessment Factor Loadings, 10 Items
TABLE 3
Athlete Demographics
Item
n 5 21
n 5 282
Demographic
1
2
3
4
7
8
9
10
11
13
Percentage variation accounted for
0.764
0.729
0.574
0.940
0.738
0.931
0.930
0.951
0.931
0.585
70.2%
0.825
0.880
0.893
0.740
0.583
0.798
0.905
0.908
0.892
0.922
74.0%
Age, y
Mean
Median
Gender
Male
Female
Sport
Baseball
Pitcher
Other
Swimming
Volleyball
Water polo
Tennis
Diving
Football
Softball
Golf
comparisons regardless of whether the shoulder or the
elbow was injured. Scores for players in like categories
were not significantly different when shoulder and elbow
injuries were compared.
Treatment Responsiveness
The final questionnaire was administered to 55 injured
overhead athletes who subsequently underwent an intervention (rest, therapy, and/or surgery) (Table 8). These
55 were not part of the 282 or 21 above. Twenty-four of
these 55 athletes (46%) completed a follow-up questionnaire at a median of 430 days (range, 63-564) after the first
questionnaire. There were no significant differences
between those athletes available for follow-up and those
who were not for age, years played, and dominant hand
(Table 8). The overall median change in the KJOC score
was 18.3 points (P 5 .0089) for the 24 respondents. Eleven
of the 24 respondents (46%) improved their injury category
to uninjured (category 1) by the time of follow-up. These 11
injured athletes who returned to play without pain (category 1) significantly improved their KJOC score a median
of 28.2 points (range, 2.9-60.7; P \ .05). The remaining 13
injured athletes who continued to report functional impairment had a median change of only 2.8 points (range, –26.2
to 11.1) in their KJOC score, which was not statistically
significant. This difference in the 2 groups was statistically
significant (P 5 .0002) (Table 9).
DISCUSSION
Valid outcome assessment tools are becoming more desirable to aid in clinical research as well as to improve patient
care. Traditional objective measures of outcomes such as
range of motion, strength, and radiographic variables
have been called into question.9 These have been found
to be poor indicators of functional and psychological health.
Patient-reported measures of quality of life generated by
the patient have been shown to be more reliable and
valid.11 Furthermore, it has been clearly demonstrated
that the physician is a poor judge of patient outcome.5
With athletes, the level of functioning once the patient
returns to competition is the true outcome measure most
n
23.7
22.0
251
31
215
112
103
38
12
5
5
2
2
1
1
important to that patient. Therefore, it follows that the
patient-athlete is the best judge of his or her outcome.
Overhead athletes may not manifest symptoms during
activities of daily living, and existing outcomes measures
may not detect problems resulting from the demands of
their training and competition. The purpose of this study
was to develop and validate a reliable and responsive outcome assessment tool for overhead athletes.
Currently, only the Conway scale has been used to
address an athlete’s functional status following injury.2
This scale has not been validated, has only been applied
to the elbow, and has not been used for sports other than
baseball. We attempted to design a questionnaire that
was not specific to a single sport, was simple to administer
and score, and was equally effective at evaluating the
shoulder and the elbow. The only currently available validated score that fits these criteria is the DASH score.
Therefore, we chose the DASH and the DASH sports/
performing arts module as the comparisons for our score.
Because the DASH score was validated on a normal population, we hypothesized that this score would be reliable
(ie, reproducible) when testing normal athletes. We further
hypothesized that the KJOC score would be more valid and
responsive than the DASH or the DASH sports/performing
arts module in this specific patient population.
We chose VAS as the format for the current questionnaire. The VAS was chosen because of its ease of generation and slightly higher sensitivity to change when
compared to a Likert scale.4 Likert scale choices are often
confusing and difficult to generate because it can be challenging to generate nonmutually exclusive answers. In
contrast, Likert scales are easier and less time-consuming
to score. Despite this limitation, our instrument is not
onerous to score and is not very time-consuming.
Our initial pilot phase of the study focused on developing a relevant questionnaire that was easy to administer
and score. Factor analysis and Cronbach a for the 13 original items were used to determine the validity of the
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TABLE 4
Kerlan-Jobe Orthopaedic Clinic (KJOC) Score by Category (n 5 282)a
Category
1: playing without pain
2: playing with pain
3: not playing
n
Minimum
Q1
Median
Mean
Q3
Maximum
SD
SEM
212
46
24
50.0
14.3
12.7
91.8
45.7
35.6
97.5
64.1
44.9
94.4
61.0
44.3
100.0
73.2
55.6
100.0
97.9
79.3
7.8
20.0
16.2
0.5
2.9
3.3
a
Q1, first quartile; Q3, third quartile; SEM, standard error of mean. Descriptive statistics for the KJOC scores by category show little
overlap between groups with tight clustering. The differences among the 3 groups are all statistically significant with P 5 .0006 or smaller
(Kruskal-Wallis test).
TABLE 5
Kerlan-Jobe Orthopaedic Clinic (KJOC) Score by History of Injury (n 5 282)a
Injury Type
Elbow
Shoulder
Other
None
n
Minimum
Q1
Median
Mean
Q3
Maximum
SD
SEM
33
68
11
169
24.2
12.7
63.1
28.0
74.6
45.6
79.5
92.1
88.4
64.1
99.4
97.6
80.0
64.7
89.0
93.3
97.4
86.4
100.0
100.0
100.0
100.0
100.0
100.0
23.3
24.7
13.5
11.2
4.1
3.0
4.1
0.9
a
Q1, first quartile; Q3, third quartile; SEM, standard error of mean. Comparison of players with history of shoulder or elbow injury to
uninjured players (includes all players currently injured).
construct in measuring functional performance. Range of
motion questions were originally incorporated into the
questionnaire because of the biomechanical importance of
full, unrestricted range of motion in this population. However, the questions that attempted to have the athletes
assess their own range of motion did not perform well in
either correlation, nor did they vary much. Based on the
clear statistical inferiority, these items were removed.
After the modifications, the instrument’s reliability
improved from 0.86 to 0.88. Estimates of acceptable reliability have ranged from 0.85 to 0.94 when the instrument
is being used to make a treatment decision for a specific
patient.7,22 While retest reliability was very good for the
DASH, the KJOC score outperformed the DASH among
our athletes.
The final step in validation of the KJOC score involved
the description of the population norms and the comparison
of groups within that population. The administration of the
KJOC score to the large sample size had the added intention
of quantifying clinically relevant variations in the score
through the comparisons among athletes with injuries.
The KJOC score accurately stratified athletes by injury category, with median scores significantly different from each
other in all cross-category comparisons. Athletes with a history of injury, a current injury, or an inactive status scored
significantly lower than their uninjured counterparts.
When an athlete returned to competition after an intervention, the median change in the KJOC score was highly significant and returned to near normal for uninjured athletes.
Our study had several strengths. Our clinic services
a highly active and demanding professional, collegiate,
and recreational population of athletes. This population
exposure allowed a unique experience with injuries in
TABLE 6
P Values for Pairwise Comparisons (Kruskal-Wallis)
Group
Versus Group
Elbow
Elbow
Elbow
Shoulder
Shoulder
Other
Shoulder
Other
None
Other
None
None
P Value
.0022
.2347
.0003
.0013
.0000
.7376
high-level overhead athletes, as well as with their outcomes after treatment. Furthermore, the KJOC score represents the only available assessment tool specifically
designed for the overhead athlete. We followed established
and accepted protocols in the development and validation
of this questionnaire.
We acknowledge several limitations of our study as
well. The relative lack of existing comprehensive upper
extremity scores for comparison makes analysis of a new
score difficult. The DASH score and DASH sports/performing arts module were the only 2 existing validated tools
that met our criteria. Reliability testing of the questionnaire was not performed on the larger sample size and is
only calculated based on the pilot group of athletes. Furthermore, the cohort group used for responsiveness testing
had a low rate of follow-up (46%). Descriptive statistics
showed there were no differences between those athletes
who returned for follow-up and those who did not for age,
years played, and dominant hand (Table 8). Further clinical studies using this new score are necessary. As specific
shoulder or elbow problems are evaluated using the
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Alberta et al
The American Journal of Sports Medicine
TABLE 7
Kerlan-Jobe Orthopaedic Clinic (KJOC) Score With and Without History of Injurya
Treatment History
None
Yes
n
Minimum
Q1
Median
Mean
Q3
Maximum
SD
SEM
119
93
50.0
62.6
94.2
86.5
99.30
94.20
96.22
91.98
100.0
100.0
100.0
100.0
6.8
8.3
0.627
0.859
a
Q1, first quartile; Q3, third quartile; SEM, standard error of mean. Comparison of players in category 1 (playing without arm trouble)
with or without a history of treatment for an injury to the shoulder or elbow. Kruskal-Wallis statistic 5 18.74, P \ .0001.
TABLE 8
Comparison of Injured Athletes Lost to Follow-up With Those for Whom Full Data Are Available
Age, y
Years played
Pretreatment score
Male gender
Right-hand dominant
Follow-up
Lost to Follow-up
19.8
11.2
59.4
11/24
21/24
20.9
10.9
50
27/31
27/31
P Value
.1786
.696
.0409
\.001
.5496
TABLE 9
Change in Kerlan-Jobe Orthopaedic Clinic (KJOC) Score After Treatmenta
Group
KJOC pretreatment
Pretreatment only
No improvement
Improvement
KJOC posttreatment
No improvement
Improvement
KJOC posttreatment minus pretreatment change
No improvement
Improvement
n
Minimum
Median
Maximum
Mean
SD
Standardized Mean (Z)
31
13
11
15.7
23.6
33.9
51.4
59.2
63.3
94.9
77.5
86
51.1
57.2
62.0
19.2
14.1
14.4
2.66
4.07
4.31
13
11
23.3
72.4
57.5
89.4
75.2
97.4
55.8
87.9
15.4
7.8
3.61
11.29
13
11
–26.2
2.9
2.8
28.2
11.1
60.7
–1.4
26.0
11.3
15.4
–0.13
1.69
a
Standardized mean 5 Z 5 mean/SD.
KJOC score, it will be necessary to continually reassess the
ability of the score to accurately stratify and predict the
level of play for these overhead athletes.
Our new patient-reported instrument is valid, reliable
in its pilot form, and responsive in the tested population
of adult overhead athletes. This questionnaire may provide
more clinically relevant information when used for overhead athletes compared to existing traditional shoulder
and elbow scoring instruments. These encouraging results
support the use of our new questionnaire for the functional
assessment of overhead athletes in future studies.
ACKNOWLEDGMENT
The authors acknowledge the contributions of Jeffrey
Gornbein, DrPH, UCLA SBCC/Department of Biomathematics, David Geffen School of Medicine, for his extensive
guidance and support of the statistical design and
analysis.
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