A prospective study of the effect of a shock-absorbing orthotic device on the incidence of stress fractures in military recruits. Prevention of common overuse injuries by the use of shock absorbing insoles. A prospective study. Prevention of lower extremity stress fractures: a controlled trial of a shock absorbent insole. The use of a pneumatic leg brace in soldiers with tibial stress fractures--a randomized clinical trial. The effect of a pneumatic leg brace on return to play in athletes with tibial stress fractures. Do shock absorbing insoles in recruits undertaking high levels of physical activity reduce lower limb injury? A randomized controlled trial. Soreness in lower extremities and back is reduced by use of shock absorbing heel inserts. The effect of pulsed ultrasound in the treatment of tibial stress fractures. Relationship between footwear comfort of shoe inserts and anthropometric and sensory factors.
In a prospective study of stress fractures the hypothesis that a shock-absorbing orthotic device worn within military boots could lessen the incidence of stress fractures was tested. The incidence of metatarsal, tibial, and femoral stress fractures was lower in the orthotic group, but only the latter difference was statistically significant. The time of onset and the location of stress fractures between orthotic and nonorthotic users did not differ. These findings suggest that the incidence of femoral stress fractures, which are the most dangerous type of stress fracture because of their high risk of developing into displaced fractures, can be reduced by an orthotic device. Sedentary individuals, particularly new military recruits, who start a physical training program have a substantial risk of developing an overuse injury of the lower limb. In this study we investigated the effect of neoprene insoles on the incidence of overuse injuries during 9 weeks of basic military training. The experimental group consisted of 237 randomly selected new recruits, while 1151 recruits were the control group. Insoles were given to the experimental group and compliance was monitored. A panel of doctors documented and classified all injuries occurring during the 9 week period. A total of 54 (22.8%) and 237 (31.9%) injuries were reported in the experimental and control groups, respectively. In both groups, the majority of injuries were overuse (experimental group, 90.7%; control group, 86.4%). The mean weekly incidence of total overuse injuries and tibial stress syndrome was significantly lower (P less than 0.05) in the experimental group. The mean incidence of stress fractures was lower in the experimental group but not significantly so (0.05 less than P less than 0.1). This study shows that the incidence of total overuse injuries and tibial stress syndrome during 9 weeks of basic military training can be reduced by wearing insoles. A prospective controlled trial was carried out to determine the usefulness of a viscoelastic polymer insole in prevention of stress fractures and stress reactions of the lower extremities. The subjects were 3,025 US Marine recruits who were followed for 12 weeks of training at Parris Island, South Carolina. Polymer and standard mesh insoles were systematically distributed in boots that were issued to members of odd and even numbered platoons. The most important finding was that an elastic polymer insole with good shock absorbency properties did not prevent stress reactions of bone during a 12-week period of vigorous physical training. To control for the confounding effects of running in running shoes, which occurred for about one and one-half hours per week for the first five weeks, we also examined the association of age of shoes and cost of shoes with injury incidence. A slight trend of increasing stress injuries by increasing age of shoes was observed. However, this trend did not account for the similarity of rates in the two insole groups. In addition, we observed a strong trend of decreasing stress injury rate by history of increasing physical activity, as well as a higher stress injury rate in White compared to Black recruits. The results of the trial were not altered after controlling for these factors. This prospective study confirms previous clinical reports of the association of stress fractures with physical activity history. The clinical application of a shock absorbing insole as a preventive for lower extremity stress reactions is not supported in these uniformly trained recruits. The findings are relevant to civilian populations. Single blind randomized controlled replication study.
                Evaluate the effect of a pneumatic leg brace on return-to-activity and pain in soldiers with tibial stress fractures.
                Thirty-one subjects diagnosed with tibial stress fractures were randomly assigned to either a brace or control group. Dependent variables included time to pain-free single-leg hopping, visual analog pain scale, and time to a pain-free 1-mile run. Twenty subjects (10 brace, 10 control) completed a detailed functional progression culminating in a 1-mile run.
                There was no difference between groups for time to pain-free hop (p > 0.86; power = 0.43) and time to pain-free 1-mile run (p > 0.24; power = 0.92). Subjects in both groups experienced statistically significant improvements in pain measurements (p < 0.002), but no difference was found between groups (p > 0.93).
                The current study demonstrated no added benefit of Aircast leg braces in the treatment of tibial stress fractures in the military training environment. A total of 18 competitive and recreational athletes were enrolled in a randomized, prospective study looking at the effect of pneumatic leg braces on the time to return to full activity after a tibial stress fracture. All patients had positive bone scans and 15 had positive radiographic findings by Week 12. There were two treatment groups. The traditional treatment group was treated with rest and, after 3 pain-free days, a gradual return to activity. The pneumatic leg brace (Aircast) group had the brace applied to the affected leg and then followed the same return to activity guidelines. The guidelines consisted of a detailed functional progression that allowed pain-free return to play. The brace group was able to resume light activity in 7 days (median) and the traditional group began light activity in 21 days (median). The brace group returned to full, unrestricted activity in 21 +/- 2 days, and the traditional group required 77 +/- 7 days to resume full activity. The Aircast pneumatic brace is effective in allowing athletes with tibial stress fractures to return to full, unrestricted, pain-free activity significantly sooner than traditional treatment. To assess the benefits, if any, of the use of shock absorbing insoles in reducing lower limb injury among Air Force recruits, and to assess the differences, if any, in the efficacy of two commonly available shock absorbing insoles.
                Randomized controlled trial.
                RAF Halton, UK. Site of all basic training for RAF personnel.
                1205 recruits participating in basic training between 17 September 2003 and 7 April 2004.
                Participants were randomized to receive either standard issue Saran non-shock absorbing insoles, or shock absorbing Sorbothane or Poron insoles, on a 1:1:1 basis.
                The primary outcome measure was withdrawal from training for lower limb injury. The two primary comparisons were shock absorbing insole versus non-shock absorbing insole, and Sorbothane versus Poron (comparison of different shock absorbing insoles). Secondary outcomes were medical withdrawals for reasons other than those qualifying for the primary outcome measure.
                When comparing the non-shock absorbing insole to the shock absorbing insoles 72/401 participants (18.0%) allocated to Saran insoles were removed from training because of a qualifying lower limb injury, compared with 149/804 (18.5%) allocated to the shock absorbing insole (Sorbothane or Poron), odds ratio 1.04 (95% CI 0.75 to 1.44; P=0.87). When comparing the two shock absorbing insole 73/421 participants (17.3%) randomized to Sorbothane were removed from training because of a qualifying lower limb injury, compared with 76/383 for Poron (19.8%), odds ratio 0.85 (95% CI 0.58 to 1.23; P=0.37).
                Similar rates of lower limb injuries were observed for all insoles (shock absorbing and non-shock absorbing) in the trial. The trial provides no support for a change in policy to the use of shock absorbing insoles for military recruits. Soccer referees participating in large soccer tournaments may develop overuse injuries. In this study the effect of shock absorbing heel inserts in the incidence of soreness was investigated. Forty-eight referees were randomly selected to wear shock absorbing heel inserts (SAH) in the 5 day-tournament, while 43 referees were the control group. A daily questionnaire inquiring about complaints from the locomotive system was completed for each referee and in case of any soreness they were examined by doctors to document and classify the anatomical site. Calf, thigh, back, achilles tendon and knee were the most common localizations of overuse symptoms. The incidence of soreness in achilles tendon, calf and back were significantly reduced by the use of (SAH) inserts. Tibial stress fractures commonly occur in athletes and military recruits. This prospective, randomized, double-blind clinical study sought to determine whether pulsed ultrasound reduces tibial stress fracture healing time. Twenty-six midshipmen (43 tibial stress fractures) were randomized to pulsed ultrasound or placebo treatment. Twenty-minute daily treatments continued until patients were asymptomatic with signs of healing on plain radiographs. The groups were not significantly different in demographics, delay from symptom onset to diagnosis, missed treatment days, total number of treatments, or time to return to duty. Pulsed ultrasound did not significantly reduce the healing time for tibial stress fractures. The purposes of this study were (a) to determine lower extremity anthropometric and sensory factors that are related to differences in comfort perception of shoe inserts with varying shape and material and (b) to investigate whether shoe inserts that improve comfort decrease injury frequency in a military population.
                206 military personnel volunteered for this study. The shoe inserts varied in arch and heel cup shape, hardness, and elasticity in the heel and forefoot regions. A no insert condition was included as the control condition. Measured subject characteristics included foot shape, foot and leg alignment, and tactile and vibration sensitivity of the plantar surface of the foot. Footwear comfort was assessed using a visual analog scale. Injury frequency was evaluated with a questionnaire. The statistical analyses included Student's t-tests for repeated measures, ANOVA (within subjects), MANOVA (within insert combinations), and chi-square tests.
                The average comfort ratings for all shoe inserts were significantly higher than the average comfort rating for the control condition. The incidence of stress fractures and pain at different locations was reduced by 1.5-13.4% for the insert compared with the control group. Foot arch height, foot and leg alignment, and foot sensitivity were significantly related to differences in comfort ratings for the hard/soft, the viscous/elastic, and the high arch/low arch insert combinations.
                Shoe inserts of different shape and material that are comfortable are able to decrease injury frequency. The results of this study showed that subject specific characteristics influence comfort perception of shoe inserts.
The use of shock absorbing inserts in footwear probably reduces the incidence of stress fractures in military personnel. There is insufficient evidence to determine the best design of such inserts but comfort and tolerability should be considered.
Rehabilitation after tibial stress fracture may be aided by the use of pneumatic bracing but more evidence is required to confirm this.