Table A1.
Characteristics of Studies on Concussion Biomechanics, Biomarkers, and Imaging a
| Lead Author, Year (Country) | Study Design | Sport | Participant Age, y b | Female,% | Methods | Results |
|---|---|---|---|---|---|---|
| Biomechanics (n = 6) | ||||||
| Brainard 6 2012 (USA) | Cohort | Ice hockey | F: 19.9 ± 1.1 M: 21.4 ± 1.4 |
58 | Helmet unit with 6 single-axis linear accelerometers | Impact exposures were less frequent and of lower magnitude for women than men |
| Collins 8 2014 (USA) | Case-control | Soccer, basketball, lacrosse | High school | 59.8 | Anthropomorphic testing with handheld dynamometers and tension scales | Neck strength was a significant predictor of concussion |
| Lamond 32 2018 (USA) | Cross-sectional | Soccer | F: 19.7 ± 1.2 | 100 | Smart Impact Monitor accelerometers | Nonheader impacts resulted in higher mean linear accelerations than purposeful headers |
| Stojsih 55 2010 (USA) | Cohort | Amateur boxing | F: 24 M: 22 |
50 | Impact boxing headgear | Magnitude of impacts was similar for both sexes. There were significantly fewer impacts in women |
| Tierney 56 2008 (USA) | Cross-sectional | Soccer | F: 19.5 ± 1.8 M: 20.3 ± 2.9 |
65.9 | Anthropometric, isometric strength (dynamometer) and head kinematics (mouthpiece accelerometer) assessments | Lower head-neck segment stability qualities and greater head accelerations in women than men |
| Wilcox 60 2014 (USA) | Cohort | Ice hockey | College | 58.6 | Head Impact Telemetry System | Lower number of impacts with lower acceleration magnitudes in women than men |
| Biomarkers (n = 1) | ||||||
| Stalnacke 54 2006 (Sweden) | Before/After | Elite soccer | F: 23 ± 3 | 100 | S-100B, NSE | Concentrations of S100-B and NSE were increased after a game; changes in S100-B correlated with the number of headers/other trauma events |
| Imaging (n = 3) | ||||||
| Ghajari 22 2017 (UK) | Cohort | Professional American football | Control: 35.52 ± 17.65 TBI: 38.01 ± 12.45 |
40.5 | Injury modeling (helmet-to-helmet collision, fall from ground level/road traffic accident), DTI/FA | Brain tissue deformation induced by head impact loading was greatest in sulcal locations |
| Helmer 26 2014 (Canada) | Case-control | Ice hockey | F: 21 ± 4 M: 23 ± 2 |
44.4 | SWI, hypointensity burden index | Women had a lower HBI than men at the beginning and the end of the season; rise in the burden was significant for men but not for women |
| Rubin 44 2018 (USA) | Cross-sectional | Soccer | F: 25.8 (20-28) M: 25.7 (20-28) |
50 | DTI, FA | In women more widespread evidence of microstructural white matter alteration than in men |
a
DTI, diffusion tensor imaging; FA, fractional anisotropy; F, female; HBI, hypointensity burden index; M, male; NR, not reported; NSE, neuron-specific enolase; S100B, S100 calcium-binding protein B; SWI, susceptibility weighted imaging; TBI, traumatic brain injury.
b
Data are presented as mean, mean ± SD, or mean (range). Competition level is given where specific ages were not provided.