(59) THE EFFECTS OF REPETITIVE HEAD IMPACTS ON REACTION TIME TESTS IN LAW ENFORCEMENT CADETS

Repetitive head impacts (RHI) in combat sports are common and may have short- and long-term consequences, such as impaired reaction time. Law enforcement cadets (LECs) may experience RHIs as part of combative training. Reaction time is a vital skill for LECs who are often placed in situations requiring quick thinking and movement.

Purpose: To examine the effect of RHIs on simple reaction time (SRT) and Go/No Go reaction time (GRT) in LECs.

Methods: Participants were recruited from a sheriff’s office training academy and completed a Defensive Tactics Assessment (DT) and a Physical Abilities Test (PAT). The DT involves RHIs, while the PAT is physically demanding but does not involve RHIs. SRT and GRT tests were completed on the Bertec Vision Trainer (BVT, Bertec Corp., Columbus, OH) before (PRE) and after testing (POST) for both DT and PAT. Participants completed 7 trials of the SRT, and primary outcomes were fastest reaction time and response time. The GRT consisted of three 30 second trials, where 50% of the targets indicated “Go.” Primary outcomes were percent of correct targets captured and average response time. Data were analyzed using generalized estimating equation models using IBM SPSS (version 28, Chicago, IL, US) with an a priori alpha level of < 0.01.

RESULTS: 36 LECs (29.2­±7.8 y.o., 7F/29M, 176.8±9.0cm, 94.6±24.6kg) completed the DT and 31 participants (29±8.3 y.o., 6F/25M, 177.1±9.1cm, 95.9±24.9kg) completed the PAT. For the SRT, the time-by-session interaction was significant for reaction time (p=0.003), whereby PRE-DT was slower (B=0.017, p=0.05 PRE 0.33±0.03s) compared to the PRE-PAT(0.32±0.05s). For response time, the main effect of time was significant (p=0.003), with faster response times (B=-0.017 POST DT = 0.51±0.06s PAT = 0.51±0.07s) POST compared to PRE for DT (0.53±0.06s) and PAT (0.52±0.06s). No other interactions or main effects were significant for reaction or response times (p >0.01). For GRT, only the main effect of time was significant for response time (p< 0.001) with faster response times (B=-0.026 DT 0.67±0.06s PAT = 0.51±0.07s) at POST compared to PRE for DT(0.69±0.04s) and PAT(0.52±0.06s). No other interactions or main effects were significant for correct targets captured or response time (p >0.01).

CONCLUSIONS: Given the occupational demands of law enforcement, rapid decision-making is paramount for LECs. Our analyses revealed no significant impairments in reaction time, response time, capture of "GO" targets, or Go/No-Go response after DT, despite the occurrence of RHIs. Such findings are indicative of the resilience of reactive decision-making processes among LECs. Consequently, our results are encouraging and suggest that the capacity of LECs to execute appropriate responses under such circumstances is likely unimpaired. Although our study sheds light on the effects of short-term RHI exposure on the decision-making in LECs, further research is necessary to investigate the long-term effects of repeated exposures on reaction time, including potential cumulative effects.

 


PRACTICAL APPLICATIONS: While controlled settings of DT and PAT offer useful insights into the impact of RHIs on the decision-making capabilities of LECs, incorporating training applications may be beneficial to ensure sustained performance. Training of LECs may include interventions to improve/sustain reaction time that combine cognitive and visual training with motor tasks to help with performance in real-life settings.

 
 




 



Acknowledgements: Supported by U.S. Department of Defense/Office of Naval Research, Defense University Research Instrumentation Program.