Concerns Over Head Impacts in Youth Contact Sports
Rising Public Awareness
The issue of repeated head hits in youth contact sports has garnered significant public concern. Research indicates that these impacts, even in the absence of concussions, may lead to long-term brain damage. Statistics reveal that the average youth football player experiences around 107 head impacts per season, while high school players average about 565.
Understanding the Near Point of Convergence Test
A specific eye test known as the near point of convergence (NPC) has shown potential in identifying neuronal damage before symptoms manifest. Dr. Keisuke Kawata stated in a press release, “NPC has been shown to detect damage to neurons before symptoms appear.” Neurons, which are responsible for transmitting information within the body, are critical in assessing brain health. NPC measures how close a person can focus on an object without experiencing double vision. In prior studies, NPC measurements successfully differentiated between nearly 75% of concussed athletes and those without concussions.
Recent Study on High School Football Players
A recent study published in JAMA Ophthalmology represents the first investigation into NPC values among high school football players who sustained multiple head impacts without concussions in a single season. The study focused on 12 male athletes free from previous head and neck injuries or brain disorders. NPC measurements were taken at multiple points: preseason, before and after in-season games, and postseason, resulting in a total of 14 data points. Participants were equipped with a device to monitor the number and intensity of head impacts during practices and games, along with a heart rate monitor to assess the impact of exercise on NPC results.
Findings and Implications
The researchers found a decline in NPC measurements correlating with increased head impacts among the football players. Notably, these measurements did not quickly return to preseason levels. However, NPC values began to show signs of recovery midseason, despite continued head impacts. These findings suggest that NPC values could serve as indicators of potential hidden brain damage in athletes facing repeated head injuries. Furthermore, it appears that the visual system may adapt to ongoing head trauma, although the mechanisms of recovery remain unclear.
Study Limitations and Future Research
The study’s limitations include a small sample size and the absence of a control group. Further clinical research involving a larger cohort of athletes and an in-depth examination of the visual system is necessary to validate these findings.
References
– Zonner SW, Ejima K, Fulgar CC, et al. Oculomotor response to cumulative subconcussive head impacts in US high school football players [published online ahead of print December 20, 2018]. JAMA Ophthalmol. doi:10.1001/jamaophthalmol.2018.6193.
– Daniel RW, S Rowson, SM Duma. Head impact exposure in youth football. Ann Biomed Eng. 2012;40(4):976-981. doi:10.1007/s10439-012-0530-7.
– Study examines head impacts, changes in eye function in high school football players [news release]. Bloomington, IN: JAMA Ophthalmology; December 20, 2018. https://www.eurekalert.org/pub_releases/2018-12/jn-seh121918.php. Accessed January 2, 2019.
– Cherry K. Neurons and their role in the nervous system. Verywell Mind Web site. https://www.verywellmind.com/what-is-a-neuron-2794890. Updated November 16, 2018. Accessed January 2, 2019.