Background: In a previous study, we noted a possible connection between an athlete's weight and risk of ankle sprain. Hypothesis: A high body mass index and a history of a previous ankle sprain increase the risk of a subsequent noncontact sprain. Study Design: Cohort study; Level of evidence, 2. Methods: One hundred fifty-two athletes from 4 football teams were observed (2 varsity and 2 junior varsity). Two teams were observed for 3 seasons, and 2 teams were observed for 1 season. Before each season, body mass, height, history of previous ankle sprains, and ankle tape or brace use were recorded. Results: There were 24 ankle sprains, of which 15 were noncontact inversion sprains (11 grade I, 3 grade II, 1 grade III; incidence, 1.08 per 1000 athlete-exposures). Injury incidence was higher in athletes with previous ankle injuries (2.60 vs 0.39; P< .001). Body mass index was also a risk factor (P< .05): injury incidence was 0.52 for players with a normal body mass index, 1.05 for players at risk of overweight, and 2.03 for overweight players. Injury incidence was 0.22 for normal-weight players with no previous ankle sprain compared with 4.27 for overweight players who had a previous sprain. Conclusion: An overweight player who had a previous ankle sprain was 19 times more likely to sustain a noncontact ankle sprain than was a normal-weight player with no previous ankle sprain. Clinical Relevance: Ankle sprain prevention strategies should be targeted at football players with a high body mass index and a history of previous ankle sprains.

A high prevalence of throwing-related shoulder and elbow pain has been documented in adolescent baseball pitchers. Pitchers with a history of throwing-related pain will have weakened dominant-arm posterior shoulder musculature and greater dominant-arm glenohumeral total range of motion (ROM) loss compared with pitchers without throwing-related pain. Controlled laboratory study. Twenty-three adolescent pitchers (age 15.7 ±1.4 years) were tested. Twelve pitchers had throwing-related pain in the prior season and were currently symptom-free, while the remaining 11 pitchers had no such history of pain. Internal and external rotation ROM and muscle strength (lower trapezius, middle trapezius, rhomboids, latissimus dorsi, supraspinatus, internal rotators, external rotators) were measured bilaterally. Dominant versus nondominant differences in ROM and strength were compared between pitchers with and without throwing-related pain. As a whole, the group of 23 pitchers had a loss of internal rotation ROM (13° ± 10°, P < .001) and gain in external rotation ROM (11° ± 10°, P < .001) on the dominant versus nondominant arm, with no effect on total ROM (2° ± 7° loss, P = .14). There was no difference in bilateral comparison of total ROM between pitchers with and without throwing-related pain. Dominant versus nondominant muscle strength was lower (P < .05) for the pain group versus nonpain group for the middle trapezius (7% ± 19% vs 22% ± 12%) and supraspinatus (−4% ± 27% vs 14% ± 14%) and higher (P < .05) for the internal rotators (19% ± 14% vs 6%±12%). Throwing-related pain in this population may be due to the inability of weakened posterior shoulder musculature to tolerate stress imparted on it by adaptively strengthened propulsive muscles. Selective posterior shoulder strengthening may be indicated in rehabilitative and injury prevention programs for adolescent pitchers.

Shoulder strength and motion deficits in high school baseball pitchers have been implicated in injury risk. To prospectively determine if preseason strength and range of motion (ROM) are predictive of injury in high school baseball pitchers. It was hypothesized that ROM asymmetries and weakness would be predictive of injury. Case-control study; Level of evidence, 3. Preseason strength and ROM measurements were made on 101 pitchers from 4 different high schools over 4 seasons (total 166 pitcher-seasons: 25 freshman, 46 junior varsity, and 95 varsity player-seasons). Glenohumeral internal rotation (IR), glenohumeral external rotation, and posterior shoulder ROM were measured bilaterally. Strength in IR, external rotation, supraspinatus (empty-can test), and scapular retraction was measured bilaterally (handheld dynamometer). Injury incidence (injuries per 1000 pitches) was computed for players categorized as above normal (≥1 SD above the mean), normal (within 1 standard deviation of the mean), and below normal (≤1 SD below the mean) for each potential risk factor. Injury was defined as a missed game or practice because of shoulder or elbow problem. There were 28 upper extremity injuries (19 shoulder, 9 elbow; incidence, 0.58 injuries/1000 pitches). There was a trend for supraspinatus weakness to be associated with increased injury risk (relative risk [RR], 3.60; 95% CI, 0.75-17.32; P = .09). When analyzing major injuries only (>3 missed games), preseason supraspinatus weakness was significantly associated with increased injury risk (RR, 4.58; 95% CI, 1.40-15.01; P = .02). Paradoxically, pitchers with no IR loss were at increased risk compared with pitchers with ≥20° loss (RR, 4.85; 95% CI, 1.01-23.29; P = .04). Other ROM and strength measures were unrelated to injury risk. Although excessive loss of IR ROM is thought to be a risk factor for injury, the opposite was the case in this study. The absence of IR ROM loss in high school pitchers may indicate inadequate prior exposure to pitching, resulting in increased injury risk. Preseason supraspinatus weakness was associated with increased risk for a major injury, and preventative supraspinatus strengthening may be beneficial.