Symptoms, Sensorimotor Function, and Recovery Time Following Law Enforcement Combatives

Law enforcement cadets (LECs) complete training that prepares them for the hardest parts of their job. Subsequently, this training can involve possible head impacts (i.e., head acceleration events [HAEs]). There is limited information regarding the effect of these HAEs on acute sensorimotor function or methods that can attenuate the negative consequences of HAEs sustained in training. To fill these gaps, we conducted 2 sequential experiments. Experiment 1 examined the effects of HAEs on symptoms and sensorimotor function in LECs undergoing defensive tactics training. Experiment 2 evaluated the effect of including additional recovery time between boxing training days on reported symptomology of LECs.

For Experiment 1, 29 LECs from a local sheriff's office corrections academy participated in the study (6 women and 23 men; age: 29 ± 8 years). Participants reported concussion-related symptoms and completed sensorimotor assessments before (PRE) and after (POST) 2 training sessions: (1) a defensive tactics assessment (DTA) involving hand-to-hand combat with possible HAEs and (2) a physical abilities test (PAT) without possible HAEs. Sensorimotor assessments included visual-motor reaction time, postural control, timed up-and-go, and countermovement jumps. During DTA, LECs wore instrumented mouthguards to quantify HAE exposure. Generalized estimating equations were used to evaluate changes in outcomes from PRE to POST between the DTA and PAT. Multiple linear regressions examined the association between HAE frequency and magnitude and sensorimotor function changes (ρ ≤ 0.01). For Experiment 2, LECs were recruited from 2 consecutive academy cohorts. Cohort 1 (33 LECs, 6 women and 27 men; age: 29 ± 8 years) completed boxing training on 3 consecutive days, culminating in a boxing tournament on Day 3. Cohort 2 (11 LECs, all men; age: 29 ± 11 years) completed a modified schedule that included 3 days of recovery before the boxing tournament. Generalized estimating equations were used to evaluate the cohort-by-time interaction for total symptom number and severity (ρ ≤ 0.05).

In Experiment 1, exposure to HAEs did not affect sensorimotor function. However, the number of symptoms significantly increased from PRE (median = 1, interquartile range [IQR] = 1-3) to POST (median = 3, IQR = 3-5) for DTA but not for PAT (PRE median = 1, IQR = 1-5; POST median = 1 IQR = 1-3) (P = .003). No significant associations were observed between HAEs and sensorimotor outcomes. In Experiment 2, there was a significant increase in symptom number and severity following the boxing tournament for LECs in Cohort 1 (P < .001) but not Cohort 2 (P = .461-0.931).

Exposure to HAEs during law enforcement training did not significantly impair sensorimotor function; however, symptoms did increase. Symptom increases could be attenuated by providing additional recovery time between training events with possible HAEs. Training instructors should recognize the importance of incorporating recovery periods into law enforcement training schedules to reduce the negative cumulative effects of HAEs on symptomology and overall health.