Association of Injury History and Incident Injury in Cadet Basic Military Training

Abstract

Purpose To determine the association between injury history at enrollment and incident lower extremity (LE) injury during cadet basic training among first-year military cadets. Methods Medically treated LE injuries during cadet basic training documented in the Defense Medical Surveillance System (DMSS) were ascertained in a prospective cohort study of three large U.S. military academies from 2005–2008. Both acute injuries (ICD-9 codes in the 800–900s, including fracture, dislocations, sprains/strains) and injury-related musculoskeletal injuries (ICD-9 codes in the 700s, including inflammation and pain, joint derangement, stress fracture, sprain/strain/rupture, and dislocation) were included. Risk ratios (RR) and 95% confidence intervals (CI) were computed using multivariate log-binomial models stratified by gender. Results During basic training there were 1,438 medically treated acute and 1,719 musculoskeletal-related LE injuries in the 9,811 cadets. The most frequent LE injuries were sprains/strains (73.6% of acute) and inflammation and pain (89.6% of musculoskeletal-related). The overall risk of incident LE injury was 23.2% [95%CI: 22.3%, 24.0%]. Cadets with a previous history of LE injury were at increased risk for incident LE injury. This association was identical in males (RR=1.74 [1.55, 1.94]) and females (RR=1.74 [1.52, 1.99]). In site-specific analyses, strong associations between injury history and incident injury were observed for hip, knee ligament, stress fracture, and ankle sprain. Injury risk was greater (p<0.01) for females (39.1%) compared to males (18.0%). The elevated injury risk in females (RR=2.19 [2.04, 2.36]) was independent of injury history (adjusted RR=2.09 [1.95, 2.24]). Conclusion Injury history upon entry to the military is associated with incidence of LE injuries sustained during cadet basic training. Prevention programs targeted at modifiable factors in cadets with a prior history of LE injury should be considered.

Epidemiology of Ankle Sprains and Chronic Ankle Instability

“…Individuals with a history of acute ankle sprain have an approximately 3.5 times greater risk of sustaining another ankle sprain compared with those who have no such history. 34 This strong link between a prior ankle sprain and an increased risk for future ankle sprain is evidenced by the finding that 12% to 47% of all ankle sprains reported are recurrent. 10,21,[29][30][31] Related to the elevated risk of reinjury is the development of CAI, which involves chronic insufficiency of the lateral ligament complex.…”

“…A history of lateral ankle sprain, in particular, has been described as one of the strongest risk factors for a future lateral ankle sprain. 8,32,33 In mixed-activity populations, the strongest evidence that a prior ankle sprain is a risk factor for subsequent ankle sprain comes from a prospective cohort study 34 of 9811 military cadets: individuals with a history of ankle sprain had an approximately 3.5 times greater risk of sustaining another sprain during the study period than those who had no history of ankle sprain, even after adjusting for age, participation in an injury-prevention program, number of high school sports, and distance running index. This effect was similar for men ( As noted earlier, not only are a high proportion of all ankle sprains recurrent, but the number of prior ankle injuries sustained by the athlete is also substantial.…”

Lower Extremity Musculoskeletal Injury Risk After Concussion Recovery in High School Athletes

“…This is evidenced by the findings of our non-time-loss injuries model. Unlike concussions 5-10 and previous lower extremity injuries, [16][17][18] which increase the risk of future lower extremity injury, no evidence indicates that prior upper extremity injury influences the risk of future lower extremity injury. Hence, these time-loss upper extremity injuries resulted in less available time for sport participation without a known subsequent increase in lower extremity injury risk.…”

“…These outcomes were included in the model because previous musculoskeletal injury is a primary risk factor and predictor for future musculoskeletal injury. [16][17][18] The number of previous concussions was the number of diagnosed concussions an athlete had received before the current injury of interest.…”

A novel prophylactic parachute ankle brace CPAB

“…Ankle injuries mainly occurred during parachute training and landing, and even led to irreversible injuries, which seriously affected army combat capability [11][12][13]. Therefore, paratrooper ankle protection is an urgent problem that needs to be solved.…”