David I. Swedler

Injury Reduction Effectiveness of Selecting Running Shoes Based on Plantar Shape

Knapik, JJ, Swedler, DI, Grier, TL, Hauret, KG, Bullock, SH, Williams, KW, Darakjy, SS, Lester, ME, Tobler, SK, and Jones, BH. Injury reduction effectiveness of selecting running shoes based on plantar shape. J Strength Cond Res 23(3): 685-697, 2009-Popular running magazines and running shoe companies suggest that imprints of the bottom of the feet (plantar shape) can be used as an indication of the height of the medial longitudinal foot arch and that this can be used to select individually appropriate types of running shoes. This study examined whether or not this selection technique influenced injury risk during United States Army Basic Combat Training (BCT). After foot examinations, BCT recruits in an experimental group (E: n = 1,079 men and 451 women) selected motion control, stability, or cushioned shoes for plantar shapes judged to represent low, medium, or high foot arches, respectively. A control group (C: n = 1,068 men and 464 women) received a stability shoe regardless of plantar shape. Injuries during BCT were determined from outpatient medical records. Other previously known injury risk factors (e.g., age, fitness, and smoking) were obtained from a questionnaire and existing databases. Multivariate Cox regression controlling for other injury risk factors showed little difference in injury risk between the E and C groups among men (risk ratio (E/C) = 1.01; 95% confidence interval = 0.88-1.16; p = 0.87) or women (risk ratio (E/C) = 1.07; 95% confidence interval = 0.91-1.25; p = 0.44). In practical application, this prospective study demonstrated that selecting shoes based on plantar shape had little influence on injury risk in BCT. Thus, if the goal is injury prevention, this selection technique is not necessary in BCT.

Effect on Injuries of Assigning Shoes Based on Foot Shape in Air Force Basic Training

BACKGROUND This study examined whether assigning running shoes based on the shape of the bottom of the foot (plantar surface) influenced injury risk in Air Force Basic Military Training (BMT) and examined risk factors for injury in BMT. METHODS Data were collected from BMT recruits during 2007; analysis took place during 2008. After foot examinations, recruits were randomly consigned to either an experimental group (E, n=1042 men, 375 women) or a control group (C, n=913 men, 346 women). Experimental group recruits were assigned motion control, stability, or cushioned shoes for plantar shapes indicative of low, medium, or high arches, respectively. Control group recruits received a stability shoe regardless of plantar shape. Injuries during BMT were determined from outpatient visits provided from the Defense Medical Surveillance System. Other injury risk factors (fitness, smoking, physical activity, prior injury, menstrual history, and demographics) were obtained from a questionnaire, existing databases, or BMT units. RESULTS Multivariate Cox regression controlling for other risk factors showed little difference in injury risk between the groups among men (hazard ratio [E/C]=1.11, 95% CI=0.89-1.38) or women (hazard ratio [E/C]=1.20, 95% CI= 0.90-1.60). Independent injury risk factors among both men and women included low aerobic fitness and cigarette smoking. CONCLUSIONS This prospective study demonstrated that assigning running shoes based on the shape of the plantar surface had little influence on injury risk in BMT even after controlling for other injury risk factors.

Injury Reduction Effectiveness of Assigning Running Shoes Based on Plantar Shape in Marine Corps Basic Training

Background: Shoe manufacturers market motion control, stability, and cushioned shoes for plantar shapes defined as low, normal, and high, respectively. This assignment procedure is presumed to reduce injuries by compensating for differences in running mechanics. Hypothesis: Assigning running shoes based on plantar shape will not reduce injury risk in Marine Corps basic training. Study Design: Randomized controlled clinical trial; Level of evidence, 1. Methods: After foot examinations, Marine Corps recruits in an experimental group (E: 408 men, 314 women) were provided motion control, stability, or cushioned shoes for plantar shapes indicative of low, medium, or high arches, respectively. A control group (C: 432 men, 257 women) received a stability shoe regardless of plantar shape. Injuries during the 12 weeks of training were determined from outpatient visits obtained from the Defense Medical Surveillance System. Other known injury risk factors (eg, fitness, smoking, prior physical activity) were obtained from a questionnaire, existing databases, or the training units. Results: Cox regression indicated little difference in injury risk between the E and C groups among men (hazard ratio [E/C] = 1.01; 95% confidence interval, 0.82-1.24) or women (hazard ratio [E/C] = 0.88; 95% confidence interval, 0.70-1.10). Conclusion: This prospective study demonstrated that assigning shoes based on the shape of the plantar foot surface had little influence on injuries even after considering other injury risk factors.

Systematic review of the parachute ankle brace injury risk reduction and cost effectiveness

INTRODUCTION Military parachuting has been shown to result in injuries. This investigation systematically reviewed studies examining the influence of the parachute ankle brace (PAB) on injuries during military parachuting and performed a cost-effectiveness analysis. EVIDENCE ACQUISITION Parachute ankle brace studies were obtained from seven databases, personal contacts, and other sources. Investigations were reviewed if they contained original, quantitative information on PAB use and injuries during parachuting. Meta-analysis was performed using a general variance-based meta-analysis method that calculated summary risk ratios (SRR) and 95% CIs. EVIDENCE SYNTHESIS Five studies met the review criteria. Compared with PAB users, PAB non-users had a higher risk of ankle injuries (SRR=2.1, 95% CI=1.8-2.5); ankle sprains (SRR=2.1, 95% CI=1.4-3.1); ankle fractures (SRR=1.8, 95% CI=1.1-2.9); and all parachuting injuries combined (SRR=1.2, 95% CI=1.1-1.4). The PAB had little effect on lower body injuries exclusive of the ankle (SRR [no PAB/PAB]=0.9, 95% CI=0.7-1.2). Cost-effectiveness analysis estimated that, for every dollar expended on the PAB, a savings of about

Parachute ankle brace and extrinsic injury risk factors during parachuting

7 to

Risk factors for medical discharge from United States Army Basic Combat Training

9 could be achieved in medical and personnel costs. CONCLUSIONS The PAB reduces ankle injuries by about half and is a cost effective device that should be worn during military airborne operations to reduce injury risk.

Homicides of law enforcement officers responding to domestic disturbance calls

INTRODUCTION This study examined the injury prevention effectiveness of the parachute ankle brace (PAB) while controlling for known extrinsic risk factors. METHODS Injuries among airborne students who wore the PAB during parachute descents were compared with injuries among those who did not. Injury risk factors from administrative records included wind speed, combat loads, and time of day (day/night). Injuries were collected in the drop zone. RESULTS A total of 596 injuries occurred in 102,784 parachute descents. In univariate analysis, students not wearing the PAB (Controls) were 2.00 [95% confidence interval (95% CI) = 1.32-3.02] times more likely to experience an ankle sprain, 1.83 (95% CI = 1.04-3.24) times more likely to experience an ankle fracture, and 1.92 (95% CI = 1.38-2.67) times more likely to experience an ankle injury of any type. PAB wearers and Controls had a similar incidence of lower body injuries exclusive of the ankle [risk ratio (Control/PAB) = 0.92, 95% CI = 0.65-1.30]. After accounting for known extrinsic injury risk factors, Controls were 1.90 (95% CI = 1.24-2.90) times more likely than PAB wearers to experience an ankle sprain, 1.47 (95% CI = 0.82- 2.63) times more likely to experience an ankle fracture, and 1.75 (95% CI = 1.25-2.48) times more likely to experience an ankle injury of any type. The incidence of parachute entanglements that persisted until the jumpers reached the ground were similar among PAB wearers and Controls IRR (Control/PAB) = 1.17, 95% CI = 0.61-2.29]. CONCLUSION After controlling for known injury risk factors, the PAB protected against ankle injuries, and especially ankle sprains, while not influencing parachute entanglements or lower body injuries exclusive of the ankle.

Firearm Prevalence and Homicides of Law Enforcement Officers in the United States

Past studies indicated that overall Basic Combat Training (BCT) attrition (discharge) was associated with various risk factors. BCT has changed considerably since many of these studies were conducted. This study examined Soldiers medically attrited from BCT. Potential attrition risk factor data on recruits (n = 4,005) were collected from medical records, BCT unit records, and questionnaires. Attrition data from Fort Jackson, South Carolina, showed 203 medical discharges. Cox regression (univariate and multivariate) obtained hazard ratios and 95% confidence intervals for attrition risk factors. Higher attrition risk was associated with female gender. Higher attrition risk for men was associated with cigarette smoking, injury during BCT, and less exercise before BCT. Higher attrition risk for both genders was associated with failure on the initial 2-mile run test and separated or divorced marital status. Attrition risk factors found in this study were similar to those previously identified despite changes in BCT.

Footwear in the United States Army Band: Injury incidence and risk factors associated with foot pain

Objective To describe the law enforcement officer (LEO), encounter, perpetrator and victim characteristics of domestic disturbance-related LEO homicides in the USA from 1996 to 2010. Methods Narrative text analysis was conducted on the Federal Bureau of Investigations annual report ‘Law Enforcement Officers Killed and Assaulted’. Potential cases were confirmed if the narrative included the term ‘domestic disturbance’ or a domestic disturbance situation was described. Results 116 LEOs were killed while responding to domestic disturbance calls. Ninety-five per cent of these homicides were committed with a firearm. Sixty-seven per cent of LEOs were wearing body armour when killed; however, 52% received the fatal wound to the head/neck. Sixty-one per cent of suspects had a criminal history mentioned within the narratives and perpetrators of intimate partner violence (IPV) were more likely to be killed by LEOs than suspects involved in other forms of domestic violence. Victims of the domestic disturbance were killed in 21% of the IPV-related LEO homicide cases as opposed to only 5% of other domestic disturbance calls. A firearm was the most common weapon used in the murder of a domestic disturbance victim (86%). Conclusions This study describes domestic disturbance-related LEO homicides. Future research in this area should further examine the dangers unique to domestic disturbance calls. A longitudinal analysis could provide greater understanding of the injury and mortality risks faced by LEOs, in order to inform homicide prevention among law enforcement.

Injury risk factors in parachuting and acceptability of the parachute ankle brace

OBJECTIVES In the United States, state firearm ownership has been correlated with homicide rates. More than 90% of homicides of law enforcement officers (LEOs) are committed with firearms. We examined the relationship between state firearm ownership rates and LEO occupational homicide rates. METHODS We obtained the number LEOs killed from 1996 to 2010 from a Federal Bureau of Investigation (FBI) database. We calculated homicide rates per state as the number of officers killed per number of LEOs per state, obtained from another FBI database. We obtained the mean household firearm ownership for each state from the Behavioral Risk Factor Surveillance System. RESULTS Using Poisson regression and controlling for factors known to affect homicide rates, we associated firearm ownership with the homicide rates for LEOs (incidence rate ratio = 1.044; P = .005); our results were supported by cross-sectional and longitudinal sensitivity analyses. LEO homicide rates were 3 times higher in states with high firearm ownership compared with states with low firearm ownership. CONCLUSIONS High public gun ownership is a risk for occupational mortality for LEOs in the United States. States could consider methods for reducing firearm ownership as a way to reduce occupational deaths of LEOs.