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  • Study: As Youth Sports Intensity Grows, So Does Prevalence of Little League Shoulder

    Authors of new study say that Little League shoulder (LLS) is an underresearched condition—something that needs to change soon, because prevalence is up as more, and more intense, youth sports programs continue to proliferate.

    For the study, published in the American Journal of Sports Medicine (abstract only available for free), researchers looked at Boston Children's Hospital treatment records of 95 8- 16-year-olds diagnosed with LLS between 1999 and 2013. Although the numbers aren't large, authors claim that it's an improvement over what had been "the most instructive previous study to date," which only investigated 23 patients.

    To qualify for the study, patients had to have a diagnosis of LLS, also known as proximal humeral epiphysiolysis, with an open physis. Patients were further divided into groups with and without glenohumeral internal rotation deficits (GIRD). In addition to noting overall prevalence, researchers tracked demographics, treatment duration, recurrence rates, and possible risk factors associated with GIRD.

    The mean age of the patients in the study was 13.1 years, with 50% of all participants either 12 or 13 years old. The patient population was 98% male, and 97% of all patients were baseball players (3 patients were tennis players). Of the baseball players, 79 were pitchers, 7 were catchers, and the remaining 6 played other positions. The 2 females in the study—ages 10 and 11—were both baseball pitchers.

    Among the findings:

    • The incidence of LLS increased by an average of 8% per year, a rate of increase that was larger than growth in overall departmental and divisional patient volume.
    • Among all patients, 12 (13%) reported concurrent elbow pain, with 6 diagnosed with medial epicondyle apophysitis ("Little League elbow").
    • GIRD was diagnosed in 28 patients (30%), though authors feel prevalence may be underrepresented in their study. Ultimately they found that patients with previously-diagnosed GIRD were at higher risk for LLS, but the difference was deemed insignificant.
    • Cessation of throwing was part of the treatment recommendation for 94 of the 95 patients in the study, with an average 4.2-month resting period prescribed.
    • Physical therapy was provided to 75 patients (79%) at some point during treatment, with all GIRD patients receiving physical therapy.
    • Though 33% of patients were lost to follow-up, among the patients with adequate follow-up information, it took an average of 2.6 months to achieve resolution of symptoms, with an average return-to-play time of 4.2 months.
    • Authors believe that the clustering of LLS at ages 12 and 13 isn't surprising, as it's around that age that players move to a larger diamond that requires longer throwing distances.

    "The current study demonstrated increasing numbers of cases over the study period … which speaks to the pressing need for improved evidence in response to the evolving epidemiology of the condition," authors write.

    Authors also believe that the presence of concomitant elbow pain in 13% of the patients points to problems with how—or how often—children are throwing. "Impressively, this suggests that some young pitchers are throwing with such excessive force and/or frequency or with such poor throwing mechanics that 2 of their upper extremity joints are developing overuse injuries," they write.

    Moving forward, authors call for more research—and more care of youth sports participants.

    "As GIRD and symptom recurrence may occur in patients with LLS more than previously believed, consideration should be given toward close monitoring of patients for at least 1 year after initiation of treatment," authors write. "Current guidelines regarding pitch counts, rest, and activity modification in the setting of shoulder/arm pain should continue to be emphasized."

    Research-related stories featured in PT in Motion News are intended to highlight a topic of interest only and do not constitute an endorsement by APTA. For synthesized research and evidence-based practice information, visit the association's PTNow website.

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