The Holtz & O’Connor (2018) article Upper Extremity Functional Status of Female Youth Softball Pitchers Using the Kerlan-Jobe Orthopaedic Clinic Questionnaire was proposed to measure upper-body function and injury risk in youth softball pitchers using a questionnaire called the Kerlan-Jobe Orthopaedic Clinic (KJOC) score. The researchers studied 53 female pitchers between the ages of 12 and 18 who played on competitive travel teams. Each athlete completed the KJOC questionnaire before the season and again during the season. The questionnaire measures arm function, pain, fatigue, and performance, with scores ranging from 0 to 100 (higher scores = better function). The researchers also asked about past injuries, missed time due to injury, and pain location. Statistical tests were used to compare KJOC scores between injured and non-injured players and to see if preseason scores could predict injury risk during the season.
They found:
Overall Function (KJOC Scores)
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Average preseason KJOC score: ~87.2 ± 10.6
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Indicates generally high functional status in youth pitchers
Injury History & Pain
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32% of pitchers missed time due to injury in the previous year
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22.6% reported playing with arm trouble
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77% reported some level of pain
KJOC Scores and Injury Status
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Pitchers with previous injury had significantly lower KJOC scores:
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Injured: ~79.5
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Not injured: ~90.9 (p = .02)
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Pitchers with:
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Pain
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Arm trouble
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Prior treatment
→ all had lower functional scores
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Injury Risk Prediction (KEY FINDING)
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Pitchers with preseason KJOC < 90 had:
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3.5× greater risk of in-season injury (p = .016)
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👉 KJOC < 90 = high-risk threshold
Pain Location
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Most common pain location:
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Posterior shoulder (43%)
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Other common areas:
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Top of shoulder (34%)
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Medial elbow (28%)
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👉 Shoulder pain > elbow pain
In-Season Changes
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KJOC scores did NOT significantly change during the season (p = .64)
👉 Function stays relatively stable despite season workload
Implications: The authors concluded that youth softball pitchers generally have high levels of arm function, but a large number still experience pain and previous injuries. One of the most important findings is that pitchers with lower preseason KJOC scores were much more likely to get injured during the season. This suggests that the KJOC questionnaire can be used as a screening tool to identify athletes who may be at higher risk before the season even starts. The study also showed that shoulder pain is more common than elbow pain, which matches previous research showing high shoulder stress in windmill pitching. Interestingly, even though many athletes reported pain, their overall functional scores did not change during the season, which suggests that players may continue performing despite underlying issues. The authors recommend using preseason screening tools like the KJOC to identify at-risk athletes and implement injury prevention programs. They also note that more research is needed to understand how factors like workload, mechanics, and training affect injury risk in youth pitchers.
Key Takeaways
This paper offers a screening metric to pair with biomechanics:
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KJOC < 90 → high injury risk
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Links well with:
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The early-season injury spike reported by Smith et al. (2015)
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The idea that mechanical inefficiency leads to arm overload
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👉 You can think of this as:
“Functional red flag BEFORE mechanics break down”
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