Health, Canada (Commonwealth Union) – Concussions, often referred to as mild traumatic brain injuries, have become a prevalent concern in various sports, ranging from high-contact games like football and hockey to seemingly less combative activities such as soccer, basketball and hockey. The high-speed, intense nature of competitive sports creates an environment where collisions and impacts are inevitable, putting athletes at risk of sustaining head injuries.
A study led by Michael Hutchison, an associate professor in the University of Toronto’s Faculty of Kinesiology and Physical Education (KPE), revealed a significant reduction in the incidence and proportion of concussions suffered by NHL players due to hits to the lateral side of the head following the implementation of Rule 48. Published on JAMA Network Open, the study compared the occurrence and mechanisms of concussions before and after the introduction of Rule 48 during the NHL’s 2010-11 season. This rule aimed to prohibit direct hits to the lateral side of the head and was later expanded to include all areas of the head in the subsequent season.
The analysis encompassed 688 concussions, with 231 occurring during NHL regular seasons from 2006 to 2010 (pre-Rule 48) and 457 from the 2014 to 2019 seasons. Hutchison, the director of the concussion program at KPE’s David L. MacIntosh Sports Clinic, explained the study’s hypothesis, indicating that following the implementation of Rule 48, they would observe a change in behavior resulting in fewer concussions from head hits. The findings confirmed a notable decline in concussions post-Rule 48, particularly an 18.8 percentage point decrease in the proportion of concussions caused by hits to the lateral aspect of the head—from 34.6% (80 out of 231 concussions) before Rule 48 to 13.3% (61 out of 457) afterward.
Despite the positive change in behavior, the study noted an overall increase in the incidence of concussions between the two-time frames. However, the incidence of concussions due to hits to the lateral aspect of the head decreased from 1.6 per 100 games to 1.0 per 100 games.
Hutchison acknowledged the unexpected overall increase in concussion incidence but highlighted various contributing factors. Notably, the period following the introduction of Rule 48 coincided with heightened efforts in concussion awareness and identification. This included initiatives like a spotter program, where certified athletic trainers monitored games remotely to identify signs of possible concussions. In-arena spotters also watched games live for visible signs not captured by video. Additionally, advancements in assessment tools, improved diagnostic approaches for suspected concussions, and increased education campaigns on health risks and early detection all played roles in influencing the reported increase in concussions.
“These targeted initiatives may have resulted in greater awareness and reporting of concussion, thereby likely contributing to the increase in concussion incidence between the two periods,” says Hutchison.
“The identification and prevention of concussion is multifaceted, but of importance. Rule 48 appears to be effective for its intended purpose – eliminating behaviours that accounted for the majority of concussions in the NHL.”
Hutchison emphasizes the ongoing need to explore strategies for preventing concussions and ensuring player safety. Notably, he points out that in recent years, a majority of concussions seem to occur in specific areas around the rink, particularly along the side boards and corners.
Considering the inherent risk of collisions, whether intentional body checks or incidental impacts, Hutchison suggests that future research should focus on a thorough investigation of the behaviors and mechanisms leading to concussions resulting from player-to-player contact along the arena’s perimeter. This examination should delve into factors such as the characteristics of surfaces and environments, as well as the specific locations of head contact during these interactions.
“This study provides important insight regarding patterns of concussions and the potential influence of policies targeting health and safety.”
