Journal of Athletic Training最新文献

Context: Participation in high school sports has physical, physiological, and social development benefits, while also increasing the risk of acute and overuse injuries. Risk of sport-related overuse injury differs between boys and girls.

Objective: To investigate differences in overuse injuries among US high school athletes participating in the gender-comparable sports of soccer, basketball, and baseball/softball.

Design: Descriptive epidemiology study using a nationally representative sample from the High School Reporting Information Online (RIO) database.

Setting: High schools.

Patients or other participants: Athletes with overuse injuries during the 2006-2007 through 2018-2019 academic years.

Main outcome measure(s): National estimates and rates of overuse injuries were extrapolated from weighted observed numbers with the following independent variables: sport, gender, academic year, class year, event type, body site, diagnosis, recurrence, activity, and position.

Results: Among an estimated 908 295 overuse injuries nationally, 43.9% (n = 398 419) occurred in boys' soccer, basketball, and baseball, whereas 56.1% (n = 509 876) occurred in girls' soccer, basketball, and softball. When comparing gender across sports, girls were more likely to sustain an overuse injury than boys (soccer, injury rate ratio [IRR]: 1.37, 95% CI = 1.20-1.57; basketball, IRR: 1.82, 95% CI = 1.56-2.14; baseball/softball, IRR: 1.21, 95% CI = 1.04-1.41). Most overuse injuries in soccer and basketball for both genders occurred to a lower extremity (soccer: 83.9% [175 369/209 071] for boys, 90.0% [243 879/271 092] for girls; basketball: 77.0% [59 239/76 884] for boys, 80.5% [81 826/101 709] for girls), whereas most overuse injuries in baseball and softball were to an upper extremity (72.5% [81 363/112 213] for boys, 53.7% [73 557/136 990] for girls). For boys' baseball, pitching (43.5% [47 007/107 984]) was the most common activity associated with an overuse injury, which differed from the most common activity of throwing (31.7% [39 921/126 104]) for girls' softball.

Conclusions: Gender differences observed in this study can help guide future strategies that are more specific to gender and sport to reduce overuse injuries among high school athletes.

Context: Individuals with anterior cruciate ligament reconstruction (ACLR) often fail to return to their previous level of sport performance. Although multifaceted, this inability to regain preinjury performance may be influenced by impaired plyometric ability attributable to chronic quadriceps dysfunction. Whole-body vibration (WBV) acutely improves quadriceps function and biomechanics after ACLR, but its effects on jumping performance outcomes such as jump height, the reactive strength index (RSI), and knee work and power are unknown.

Objective: To evaluate the acute effects of WBV on measures of jumping performance in those with ACLR.

Design: Crossover study design.

Setting: Research laboratory.

Patients or other participants: Thirty-six individuals with primary, unilateral ACLR.

Intervention(s): Participants stood on a WBV platform in a mini-squat position while vibration or no vibration (control) was applied during six 60-second bouts with 2 minutes of rest between bouts.

Main outcome measure(s): Double-leg jumping tasks were completed preintervention and postintervention (WBV or control) and consisted of jumping off a 30-cm box to 2 force plates half the participant's height away. The jumping task required participants to maximally jump vertically upon striking the force plates.

Results: Whole-body vibration did not produce significant improvements in any of the study outcomes (ie, jump height, RSI, and knee work and power) in either limb (P = .053-.839).

Conclusions: These results suggest that a single bout of WBV is insufficient for improving jumping performance in individuals with ACLR. As such, using WBV to acutely improve jumping performance post-ACLR is likely not warranted. Future research should evaluate the effects of repeated exposure to WBV in combination with other plyometric interventions on jumping performance.

Context: Existing patellofemoral pain (PFP) literature has primarily been focused on quadriceps muscle volume, with limited attention given to the deep and superficial muscle volume of the lower limbs in individuals with unilateral and bilateral PFP. In this paper, we aim to fill this gap.

Objective: To explore superficial and deep lower extremity muscle volume in women with unilateral or bilateral PFP compared with a normative database of pain-free women.

Design: Cross-sectional study.

Setting: University imaging research center.

Patients or other participants: Twenty women with PFP (10 unilateral and 10 bilateral) and 8 pain-free women from a normative database.

Main outcome measure(s): We quantified lower extremity muscle volume via 3.0-T magnetic resonance imaging. Two separate 1-way analyses of variance were performed: (1) unilateral PFP (painful versus nonpainful limb) versus pain-free control groups and (2) bilateral PFP (more painful versus less painful limb) versus pain-free control groups.

Results: We observed no differences in age and body mass index across groups (P > .05). Compared with the pain-free group, the unilateral and bilateral PFP groups had bilaterally smaller volumes of the anterior (iliacus: P ≤ .0004; d range, 2.12-2.65), medial (adductor brevis, adductor longus, gracilis, and pectineus: P ≤ .02; d range, 1.25-2.48), posterior (obturator externus, obturator internus, and quadratus femoris: P < .05; d range, 1.17-4.82), and lateral (gluteus minimus: P ≤ .03; d range, 1.16-2.09) hip muscles and knee extensors (rectus femoris: P ≤ .003; d range, 1.67-2.16) and flexors (long and short head of the biceps femoris: P ≤ .01, d range, 1.56-1.93).

Conclusions: Women with unilateral and those with bilateral PFP displayed less volume of multiple superficial and deep muscles of the bilateral hips and knees than pain-free women. Interventions should bilaterally target lower limb muscles when treating PFP, and hypertrophy exercises for specific muscles should be explored to increase choices for intervention.

Context: It is unclear whether the response in femoral cartilage to running at different intensities is different.

Objective: To examine the acute patterns of deformation and recovery in femoral cartilage thickness during and after running at different speeds.

Design: Crossover study.

Setting: Laboratory.

Patients or other participants: A total of 17 healthy men (age = 23.9 ± 2.3 years, height = 173.1 ± 5.5 cm, mass = 73.9 ± 8.0 kg).

Intervention(s): Participants performed a 40-minute treadmill run at speeds of 7.5 and 8.5 km/h.

Main outcome measure(s): Ultrasonographic images of femoral cartilage thickness (intercondylar, lateral condyle, and medial condyle) were obtained every 5 minutes during the experiment (40 minutes of running followed by a 60-minute recovery period) at each session. Data were analyzed using analysis of variance and Bonferroni- and Dunnett-adjusted post hoc t tests. To identify patterns of cartilage response, we extracted principal components (PCs) from the cartilage-thickness data using PC analysis, and PC scores were analyzed using t tests.

Results: Regardless of time, femoral cartilage thicknesses were greater for the 8.5-km/h run than the 7.5-km/h run (intercondylar: F1,656 = 24.73, P < .001, effect size, 0.15; lateral condyle: F1,649 = 16.60, P < .001, effect size, 0.16; medial condyle: F1,649 = 16.55, P < .001, effect size, 0.12). We observed a time effect in intercondylar thickness (F20,656 = 2.15, P = .003), but the Dunnett-adjusted post hoc t test revealed that none of the time point values differed from the baseline value (P > .38 for all comparisons). Although the PC1 and PC2 captured the magnitudes of cartilage thickness and time shift (eg, earlier versus later response), respectively, t tests showed that the PC scores were not different between 7.5 and 8.5 km/h (intercondylar: P ≥ .32; lateral condyle: P ≥ .78; medial condyle: P ≥ .16).

Conclusions: Although the 40-minute treadmill run with different speeds produced different levels of fatigue, morphologic differences (<3%) in the femoral cartilage at both speeds seemed to be negligible.

Context: Early identification of knee osteoarthritis (OA) symptoms after anterior cruciate ligament reconstruction (ACLR) could enable timely interventions to improve long-term outcomes. However, little is known about the change in early OA symptoms from 6 to 12 months post-ACLR.

Objective: To evaluate the change over time in meeting classification criteria for early knee OA symptoms from 6 to 12 months after ACLR.

Design: Prospective cohort study.

Setting: Research laboratory.

Patients or other participants: Eighty-two participants aged 13 to 35 years who underwent unilateral primary ACLR. On average, participants' first and second visits were 6.2 and 12.1 months post-ACLR.

Main outcome measure(s): Early OA symptoms were classified using generic (Luyten Original) and patient population-specific (Luyten Patient Acceptable Symptom State [PASS]) thresholds on Knee injury and Osteoarthritis Outcome Score (KOOS) subscales. Changes in meeting early OA criteria were compared between an initial and follow-up visit at an average of 6 and 12 months post-ACLR, respectively.

Results: Twenty-two percent of participants exhibited persistent early OA symptoms across both visits using both the Luyten Original and PASS criteria. From initial to follow-up visit, 18% to 27% had resolution of early OA symptoms, while 4% to 9% developed incident symptoms. In total, 48% to 51% had no early OA symptoms at either visit. No differences were found for change in early OA status between adults and adolescents.

Conclusions: Nearly one-quarter of participants exhibited persistent early knee OA symptoms based on KOOS thresholds from 6 to 12 months post-ACLR. Determining if this symptom persistence predicts worse long-term outcomes could inform the need for timely interventions after ACLR. Future researchers should examine if resolving persistent symptoms in this critical window improves later outcomes. Tracking early OA symptoms over time may identify high-risk patients who could benefit from early treatment.