Leg power as an indicator for risk of injury or illness in police recruits

Question: Does leg power, as measured by a vertical jump, predict injury
and illness risk in a police population?
Design: Retrospective cohort study design.
Participants: New South Wales Police recruits (n=1021) undergoing a basic
police recruit training course.
Intervention A basic police recruit training course of 12 week duration.
Outcome Measures: Vertical Jump (VJ) height and formally reported
illness and injuries.
Results: 15% of participants (n=158, mean±SD VJ =42.03±7.35cm)
reported an injury, 30% (n=296, VJ =41.88±7.48cm) an illness, and 38%
(n=390, VJ =42.07±7.38cm) an illness and/or injury. The mean VJ heights
for each of these groups was significantly lower (p<.005) than those who
did not suffer an injury (VJ =44.00±7.56cm), illness (VJ =44.44±7.47cm)
or a combination of either (VJ =44.69±7.50cm). Correlations between VJ
height and prevalence of illness and injury were low (r=- 0.16 and -0.09,
respectively) but significant (p<.005), with VJ height accounting for 2.6%
and 0.8% of the variance in injury and illness rates, respectively.
Conclusion: Police recruits with lower VJ height are at a significantly
greater risk of suffering an injury or illness during police basic
recruit training.
Key Practice Points:
• Leg power is a useful predictor of injury and illness risk in recruits
undergoing police training and potentially in other tactical populations.
• Increasing leg power in new recruits about to undergo police training my
reduce their risk of injury or illness.
• Further research is required to assess the extent to which leg power is
causal in these relationships.