High School Cross-country Runners Research Articles

Fluid Replacement Knowledge and Sources of Hydration in High School Cross-Country Runners

Fluid Replacement Knowledge and Sources of Hydration in High School Cross-Country Runners

“I Love You, Guys” : A Study of Inclusive Masculinities among High School Cross-Country Runners

“I Love You, Guys” : A Study of Inclusive Masculinities among High School Cross-Country Runners

Influence of Step Rate on Shin Injury and Anterior Knee Pain in High School Runners.

High school cross-country runners have a high incidence of injury, particularly at the shin and knee. An increased step rate during running has been shown to reduce impact forces and loading of the lower extremity joints. The purpose of this prospective study was to examine step rate as a risk factor for injury occurrence. Running step rates of 68 healthy high school cross-country runners (47 females; 21 males; mean age 16.2 ± 1.3 yr) were assessed at a fixed speed (3.3 ± 0.0 m·s) and self-selected speed (mean, 3.8 ± 0.5 m·s). Runners were prospectively followed during the interscholastic season to determine athletic exposures, occurrences of shin injury and anterior knee pain (AKP), and days lost to injury. During the season, 19.1% of runners experienced a shin injury and 4.4% experienced AKP. Most injuries (63.6%) were classified as minor (1-7 d lost). At the fixed speed, runners in the lowest tertile of step rate (≤164 steps per minute) were more likely (odds ratio, 6.67; 95% confidence interval, 1.2-36.7; P = 0.03) to experience a shin injury compared with runners in the highest tertile (≥174 steps per minute). Similarly, for self-selected speed, runners in the lowest tertile (≤166 steps per minute) (odds ratio, 5.85; 95% confidence interval, 1.1-32.1; P < 0.04) were more likely to experience a shin injury than runners in the highest tertile (≥178 steps per minute). AKP incidence was not significantly influenced by step rate. A lower running step rate was associated with a greater likelihood of shin injury at both self-selected and fixed running speeds. Future studies evaluating whether increasing running step rate reduces shin injury risk and time lost during a high school cross-country season should be considered.

Functional Movement Screening and Injury Rates in High School Cross Country Runners

Functional Movement Screening and Injury Rates in High School Cross Country Runners

Running Smoothness Differs Between Trained And Untrained Individuals

A gait smoothness index has been used to identify differences in walking gait between healthy and disease populations, but has not yet been applied to running gait, where it may indicate skill differences. The index quantifies the relative level of out-of-phase harmonics in the frequency spectrum. PURPOSE: To use a cross-sectional study design to discriminate running smoothness in four groups of healthy, young subjects. METHODS: We measured 3-D trunk acceleration using optical motion capture (Vicon, Centennial, CO) at 200 Hz for 60-90 s at 3.33, 3.89, and 4.44 m·s-1. Subjects included: 1) NCAA Division I cross-country runners (n=11); 2) high school cross-country runners (n=19); 3) untrained subjects with BMI < 25 (n = 8); and 4) untrained subjects with BMI > 25 (n=8). We performed a fast Fourier transform of the mediolateral (ML), anterioposterior (AP), and vertical (VT) acceleration signal and calculated the amplitude of the first 20 harmonics. AP and VT are dominated by the second harmonic, so odd numbered harmonics (out-of-phase accelerations) detract from smoothness. The smoothness index is the ratio of the sum of the even harmonic amplitudes to the sum of the odd harmonic amplitudes. Since the first harmonic dominates ML, the smoothness index for this axis is the ratio of odd to even. A higher ratio indicates greater smoothness. We used a group×speed ANOVA to test for main effects, with a Bonferroni post hoc test where appropriate. Analyses were performed in Matlab (2013b, Mathworks, Natick, MA). RESULTS: College and high school runners had higher AP smoothness than untrained-low BMI and untrained-high BMI (6.74 and 7.54 versus 4.33 and 4.43, respectively, p<0.05). For VT, college and high school runners had higher smoothness than untrained-high BMI (10.91 and 10.26 versus 6.75, respectively, p<0.05). High school runners also had a higher VT smoothness than untrained-low BMI (10.26 versus 8.32, respectively, p<0.05). There were no speed effects or any group×speed interactions (p>0.05). CONCLUSION: Running smoothness was significantly different between trained and untrained subject groups. It is unknown if this is due to training effects on biomechanics and motor control, training-associated body composition changes, or pre-existing characteristics leading to self-selection of running, all of which might change the contribution of out-of-phase movement to the AP and VT acceleration signal.

Summer training factors and risk of musculoskeletal injury among high school cross-country runners.

Prospective cohort. To examine the relationship between summer training practices and risk of injury during the first month of a high school interscholastic cross-country season. Several prospective studies have reported a high incidence of injury in adolescent cross-country runners. However, limited reports exist on the role of summer training practices and risk of injury among these runners. Four hundred twenty-one athletes (186 girls, 235 boys) who competed in interscholastic cross-country were followed during a cross-country season. At the start of the season, all participants completed a questionnaire regarding summer training routines. Time-loss, running-related injuries were tracked during the subsequent season. Logistic regression analysis was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of initial injury during the first month of the season associated with summer training variables. Sixty-seven runners (15.9%) had a confirmed injury during the first month of the season, with a higher percent among girls (19.4%) than boys (13.2%) (P = .06). Overall, 60.1% of the participants ran during the summer prior to the season, with a significantly higher percent among girls (71.5%) than boys (51.1%) (P<.0001). Overall, no significant association (OR = 0.9; 95% CI: 0.5, 1.5; P = .90) was found between not running sometime during the preceding summer and increased risk of initial injury during the first month of the season. Among only the runners who ran during the summer, after adjusting for sex and prior injury, first-month injuries were more common among those who did not frequently alternate short and long mileage on different days (OR = 3.0; 95% CI: 1.4, 6.4; P = .005), and/or who ran 8 weeks or fewer (OR = 2.7; 95% CI: 1.2, 5.8; P = .01) during their summer training. Running 8 weeks or fewer (P = .03), not frequently alternating mileage on different days (P = .01), and running a higher percentage of time on predominantly hill (P = .001) and irregular terrains (P = .004) were associated with increased risk of injury for girls. These findings suggest that injuries during the first month of the high school cross-country season may be reduced if runners who participate in summer training activities run a greater number of weeks and frequently vary their daily running mileage during the summer. For girls, training programs that reduce mileage on hills and irregular terrains may help to minimize the occurrence of running-related injury. Prognosis, level 1b-.

The Association Between Quality Of Movement And Dynamic Stability In High School Cross Country Runners.

The Association Between Quality Of Movement And Dynamic Stability In High School Cross Country Runners.

Underwater Treadmill Training in High School Cross Country Runners

Underwater treadmill exercise (UTM) is emerging as an innovative method of athlete rehabilitation but there has been little research on its injury prevention and performance enhancement. The low-impact nature of UTM has been suggested to expedite injury recovery while providing a cardiovascular training effect similar to dry-land exercise. PURPOSE: To assess overuse symptoms and injury rate of a UTM exercise intervention on a high school cross country team. We hypothesized that the UTM would decrease the orthopedic problems in these young athletes who are susceptible to a high rate of overuse symptoms. METHODS: 16 subjects (16 ± 2 yr) exercised on a HydroWorx™ UTM in groups of 2-4 runners for 30-45 minutes, 1-2 times per week for 10 weeks in place of a dry-land practice. UTM was submerged to the level of the xyphoid process. Runners began with a 6 to 10 minute dynamic warm-up at an RPE of 1-2 / 10. Workouts then emphasized either low intensity (avg UTM speed 148 m/min, 25% flow from horizontal jets, RPE 3-6) or speed (avg speed 188 m/min, 70% jet flow, RPE 5-10). Daily questionnaires regarding injuries, discomfort, flexibility, and performance were administered before dry land and UTM practices. Race times were gathered and follow-up surveys were completed at the conclusion of the season. RESULTS: For the season there were two injuries (one male and one female) resulting in one missed meet each and thus a rate of 1.8 injuries/1000 athletic exposures (AE). There were five minor orthopedic complaints (shin splints and hip pain) not serious enough to miss meets but resulting in missed practices. This injury rate was a great improvement over the previous season as well as historical controls (which suggest a rate of 17/1000 AE). As well as could be compared to the previous year, race times were not consistently faster. CONCLUSION: The young runners were enthusiastic about the UTM experience. Quotes supporting our observed reduction in overuse symptoms included: "easier on your knees," "it's better than sprinting outside all the time" and from the coach "they like it a lot, otherwise they would not come." With our small sample size we cannot say for sure that the benefits observed were only due to the UTM. Future research, including any measurable performance benefits, would need to be done on a larger sample over several seasons.

Attitudes and Beliefs Regarding Menstrual Cycles, Caloric Needs and Performance in High School Cross-country Runners

Attitudes and Beliefs Regarding Menstrual Cycles, Caloric Needs and Performance in High School Cross-country Runners

Do Preseason Running Mileage and Video Analysis Predict In-season Injury Among High School Cross Country Athletes

Cross country is a popular high school sport. Over one third of high school cross country runners sustain a lower extremity injury each season. Despite this high rate of injury, there is little known about risk factors for injury in this population or appropriate preseason running mileage. Identification of risk factors has been limited to static alignment measures which have not been proven to be reliable measures for dynamic movements, such as running. Increased Q-angle (valgus) has been proposed as a possible predictor for injury in high school runners but has not been a reliable measure when utilizing 2D video analysis. Frontal plane projection angle (FPPA) has been found to be a reliable 2D measure of this valgus angle during dynamic running analysis. PURPOSE: To determine if increased FPPA and summer running mileage predict lower extremity injury during one high school cross-country season. To describe gender differences in running gait analysis for teenage runners. METHODS: Demographics, running history, anthropometric measures and running video analysis were collected on 28 (17 males, 11 females) high school cross country runners. Running related injury incidence was recorded during the 2008 cross country season. RESULTS: 10 athletes reported an injury during the cross country season. All injuries occurred to the lower extremity. Mean FPPA for injured was not significantly different than non-injured (p=.73). Mean preseason running mileage per week was less in injured (20.7 miles/week) compared to non-injured (26.6 miles /week) (p=.12). Gender analysis revealed females had significantly higher mean FPPA (9.3° vs 6.4°, p=0.03), lower mean hip external rotation strength (8.6kg vs 12.3kg, p=.0001) and hip drop (82% vs 41%, p=0.03). CONCLUSION: Lower preseason training mileage (inadequate preseason conditioning) may be a risk factor for injury for male and female high school cross country runners. Females demonstrated increased FPPA and hip drop during 2D running video analysis which may predispose them to higher incidence of running related injuries

Physiological Adaptations and Analysis of Training Content in High School Cross-Country Runners

The purposes of this study were to examine effects of a season of training on aerobic performance in cross-country distance runners and to analyze the training using subjective and objective techniques. Subjects averaged 184 minutes of running per week, with 45%, 24%, and 31% occurring in zones below, near, and above the heart rate (HR) corresponding to ventilatory threshold (VTHR), respectively (Zone 1: HR > 15 bpm below VTHR; Zone 2: HR between Zone 1 and VTHR; Zone 3: HR > VTHR). Maximal oxygen uptake ([Vdot]O2max) increased by 5.1%, 5-km race time by 46 seconds (3.7%), and 2-km time trial performance by 54 seconds (10.7%) from pre- to postseason. Results are similar to previous research demonstrating that short-term (< 3 months) endurance training elicits improvements in various physiological parameters. Findings were not consistent with previous research that suggests a discrepancy may exist between the runners' perceptions and the physiological effects of their training.

Quadriceps Angle and Risk of Injury Among High School Cross-Country Runners

Quadriceps Angle and Risk of Injury Among High School Cross-Country Runners

Medial Tibial Stress Syndrome in High School Cross-Country Runners: Incidence and Risk Factors

Medial Tibial Stress Syndrome in High School Cross-Country Runners: Incidence and Risk Factors

Quadriceps Angle and Risk of Injury Among High School Cross-Country Runners

Prospective cohort study. To determine the relationship between quadriceps angle (Q-angle) and risk of lower extremity injury among adolescent cross-country runners. No consensus exists on the role of the Q-angle as a risk factor for lower-extremity overuse injury, especially the effect of large Q-angle or right-left Q-angle difference. The Q-angles of 393 high school cross-country runners, 13 to 19 years of age, were goniometrically measured in a static, standing position with quadriceps relaxed. The runners were followed during a cross-country season to assess lower extremity injuries resulting from running in practices or competitions. Runners with a Q-angle >20 degrees were at 1.7 times greater risk of injury (relative risk [RR], 1.7; 95% confidence interval [CI]: 1.2, 2.4) compared with runners whose Q-angle was 10 degrees to <15 degrees . The RR estimates were similar among girls and boys. Runners with >4 degrees absolute right-left Q-angle difference were at 1.8 times greater risk (RR, 1.8; 95% CI: 1.4, 2.5) compared to runners with a smaller difference. Runners with a Q-angle >20 degrees were more likely to injure their knee, while runners with >4 degrees Q-angle difference were more likely to injure their shin. Runners with a Q-angle >20 degrees had greater time lost due to injury. High school cross-country runners with large or asymmetric Q-angles may be at greater risk for running injury. Our study suggests that Q-angle measurement be included in preseason screening exams.

The Use of Global Positioning System (GPS) to Monitor Training and Model Performance in High School Cross Country Runners

The Use of Global Positioning System (GPS) to Monitor Training and Model Performance in High School Cross Country Runners

Lower Extremity Injuries among High School Cross-Country Runners

Lower Extremity Injuries among High School Cross-Country Runners

Medial Tibial Stress Syndrome in High School Cross-Country Runners: Incidence and Risk Factors

Prospective cohort. To determine (1) the cumulative seasonal incidence and overall injury rate of medial tibial stress syndrome (MTSS) and (2) risk factors for MTSS with a primary focus on the relationship between navicular drop values and MTSS in high school cross-country runners. MTSS is a common injury among runners. However, few studies have reported the injury rate and risk factors for MTSS among adolescent runners. Data collected included measurement of bilateral navicular drop and foot length, and a baseline questionnaire regarding the runner's height, body mass, previous running injury, running experience, and orthotic or tape use. Runners were followed during the season to determine athletic exposures (AEs) and occurrence of MTSS. The overall injury rate for MTSS was 2.8/1000 AEs. Although not statistically different, girls had a higher rate (4.3/1000 AEs) than boys (1.7/1000 AEs) (P = .11). Logistic regression modeling indicated that only gender and body mass index (BMI) were significantly associated with the occurrence of MTSS. However, when controlled for orthotic use, only BMI was associated with risk of MTSS. No significant associations were found between MTSS and navicular drop or foot length. Our findings suggest that navicular drop may not be an appropriate measure to identify runners who may develop MTSS during a cross-country season; thus, additional studies are needed to identify appropriate preseason screening tools.

Relationships Between the Eating Disorder Examination Questionnaire Subscales, Bone Mineral Density and Menstrual Irregularity in Female High School Cross Country Runners

Relationships Between the Eating Disorder Examination Questionnaire Subscales, Bone Mineral Density and Menstrual Irregularity in Female High School Cross Country Runners

Lower BMD Z-scores in Older vs. Younger Female High School Cross-Country Runners

Currently, it is unclear if low bone mineral density (BMD) values reported in female long distance runners are a result of inadequate bone mass accrual or loss of bone mass. PURPOSE: Our purpose was to compare BMD (g cm2) and Z-scores (age, height, weight, and race-matched SD values) by age in female high school distance runners. METHODS: Female cross-country runners (N=148) 13–18 years old (mean 15.9 ± 1.2 y) from 12 high schools in southern California participated in the study. BMD of the spine (L1-L4) and total body was assessed by dual energy x-ray absorptiometry (DXA; GE/Lunar), and Z-scores were determined from the manufacturer's pediatric database. Four age groups (13–14y, 15y, 16y, 17–18y) were compared by ANOVA and Bonferroni post hoc tests. RESULTS: The mean lumbar spine Z-score of the 13–14 y age group (0.2 ± 1.3) was significantly higher than that for the 17–18 y age group (−0.9 ± 1.2, p< 0.01). There was a trend towards a higher mean total body Z-score in the 13–14 vs 17–18 y age group (0.7 ± 0.9 vs 0.0 ± 0.9, p= 0.059). No significant differences were found in BMD (g cm2) among age groups for either the total body or lumbar spine. CONCLUSIONS: In girls, approximately 40% of bone mass is accrued during adolescence, with peak bone growth velocities occurring at approximately ages 12–15 years. In our study, the runners BMD (an absolute bone mass measure) remained constant while Z-scores (a relative bone density measure) decreased. This finding supports the hypothesis that, in female high school competitive cross-country runners, bone mass may not be increasing at a rate similar to that reported for a reference population. Longitudinal studies tracking BMD in high school runners over time are necessary to confirm this hypothesis. This study was funded in part by grants from the National Athletic Trainers Research Foundation, and the Frederick W. Kasch Endowment.

Epidemiology of Musculoskeletal Injuries among High School Cross-Country Runners

To determine the incidence of lower-extremity injury among high school cross-country runners and to identify risk factors for injury, the authors prospectively monitored a cohort of 421 runners competing on 23 cross-country teams in 12 Seattle, Washington, high schools during the 1996 cross-country season. Collected were daily injury and athletic exposure (AE) reports, a baseline questionnaire on prior running and injury experience, anthropometric measurements, and coaches' training logs. The overall incidence rate of injury was 17.0/1,000 AEs. Girls had a significantly higher overall injury rate (19.6/1,000 AEs) than boys did (15.0/1,000 AEs) (incidence rate ratio = 1.3, 95% confidence interval: 1.0, 1.6). Compared with boys, girls had significantly higher rates of injuries resulting in >or=15 days of disability. For the overall sample and for girls, Cox regression revealed that a quadriceps angle of >or=20 degrees and an injury during summer running prior to the season were the most important predictors of injury. For boys, a quadriceps angle of >or=15 degrees and a history of multiple running injuries were most associated with injury. Results suggest that the incidence of lower-extremity injuries is high for cross-country runners, especially girls. Preseason screening to determine risk factors should be examined as a preventive approach for identifying high-risk runners.