Abstract
Background:
High school athletes participating in cross-country sports are at increased risk of overuse injuries. Little is known in younger athletes including those participating in running during middle school regarding prevalence of injuries or related risk factors. The objective of this study was to assess the frequency of sports-related injuries in middle school cross-country runners.
Methods:
This was a retrospective online survey study of middle school cross-country runners. Middle school cross-country coaches from middle school teams in the Boston area sent letters of invitation via email to the parents of their athletes to participate in an optional, anonymous online survey administered in REDCap. Participants received a $5 gift card for their time. The online survey included demographic information, weight, height, training variables, daily dietary patterns, and injury history. We conducted univariate and bivariate analyses while stratifying for sex.
Results:
A total of 101 subjects completed the survey, 47% (n=48) were female. Mean age was 12.5 years [SD 0.94], and 24% (n=24) were in sixth grade, 39% (n=39) in seventh grade, and 38 % (n=38) in 8th grade. The mean BMI for girls was 17.9 kg/m2 and for boys 18.24 kg/m2. The self-reported race/ethnicity was white in 72% (n=72), Asian in 22% (n=22), Latino in 5% (n=5), and black in 1% (n=1). Mean weekly mileage during the cross-country season was 15.2 miles [SD 7.6]. Of female subjects, 17% (n=8) reported that they were diagnosed with a bone stress injury (BSI) due to running, compared to 2% (n=1) of male subjects, p=0.009. The injured bones in females included the tibia (n=1), fibula (n=1), navicular (n=1) and metatarsal bones (n=6). The injured bone in the male was a sacral fracture. Compared to those without injury, runners with BSIs did not have observed differences in calcium or vitamin D intake; no differences were observed related to ball sport or other forms of strengthening exercises. A total of 63 non-fracture injuries occurred from running, with females (18%) more likely to have sprained ankles than males (6%, p=0.47).
Conclusions/Significance:
Running-related injuries are relatively common in middle school cross-country runners. In middle school, female runners are more likely to sustain running related BSIs than male runners. Efforts to prevent overuse stress injuries in middle school runners should be considered.
Demographic and injury history of middle school runners
| N=101 | All (n=101) | Girls (n=48) | Boys (n=53) | P value |
|---|---|---|---|---|
| Age (years) | 12.45 [0.94] | 12.41 [0.81] | 12.49 [1.05] | 0.66 |
| Grade 6th 7th 8th |
24% (24) 39% (39) 38% (38) |
22% (11) 41% (20) 37% (18) |
25% (13) 37% (19) 39% (20) |
0.73 |
| Weight (kg) | 44.3 [8.08] | 42.0 [7.022] | 46.4 [8.19] | 0.006 |
| Height (cm) | 155 [18.4] | 150.9 [23.3] | 160 [11.81] | 0.021 |
| BMI (kg/m2) | 18.09 [2.99] | 17.94 [3.30] | 18.24 [2.69] | 0.62 |
| Race/ethnicity White Latino Black Asian/Pacific Islander Other |
72% (72) 5% (5) 1% (1) 22% (22) 1% (1) |
71% (34) 8% (4) 2% (1) 19% (9) 0%(0) |
77% (41) 3% (1) 0% (0) 25% (13) 2% (1) |
0.34 |
| Absences from training last year due to injury None Once or twice 3-4 times 5 or more Didn’t run last year |
52% (53) 35% (36) 8% (8) 2% (2) 3% (3) |
47% (23) 39% (19) 8% (4) 2% (1) 4% (2) |
57% (30) 32% (17) 8% (4) 2% (1) 2% (1) |
0.88 |
| Diagnosed with a bone stress injury by a doctor | 11% (11) | 19% (9) | 4% (2) | 0.016 |
| Diagnosed with a bone stress injury by a doctor due to running | 9% (9) | 17% (8) | 2% (1) | 0.0092 |
| Injured bone Tibia Fibula Metatarsal Sacrum |
1* 2* 6 (1 female had both tibia/fibula fracture) |
0 0 0 1 |
||
| Injuries Total injuries Achilles tendonitis Shin splints Runner’s knee IT band syndrome Sprained ankle Hamstring strain Osgood-Schlatter Disease Sever disease Other tendon/bone/joint injury Plantar fasciitis |
(63) 8% (8) 5% (7) 13% (14) 1% (1) 12% (12) 4% (4) 4% (4) 8% (8) 5% (5) 3% (3) |
(39) 8% (4) 6% (3) 20% (10) 0% (0) 18% (9) 6% (3) 6% (3) 4% (2) 6% (3) 4% (2) |
(25) 8% (4) 4% (2) 8% (4) 3% (1) 6% (3) 2% (1) 2%(1) 11% (6) 4% (2) 2% (1) |
0.91 0.58 0.059 0.30 0.047 0.27 0.27 0.17 0.58 0.51 |
*Some subjects had more than one injury.