You will be provided with the titles and abstracts of a collection of medical RCT reports studying a clinical question -- for instance, the efficacy of an intervention on some medical outcome. Please write a few sentences synthesizing the findings of these reports, which could serve as a conclusion section for a systematic review article. Your response should not include any other text. The RCT reports are below.



Title 1:
The effect of a pneumatic leg brace on return to play in athletes with tibial stress fractures.
Abstract 1:
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.


Title 2:
The use of a pneumatic leg brace in soldiers with tibial stress fractures--a randomized clinical trial.
Abstract 2:
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.


Title 3:
A randomized trial of preexercise stretching for prevention of lower-limb injury.
Abstract 3:
This study investigated the effect of muscle stretching during warm-up on the risk of exercise-related injury.
                1538 male army recruits were randomly allocated to stretch or control groups. During the ensuing 12 wk of training, both groups performed active warm-up exercises before physical training sessions. In addition, the stretch group performed one 20-s static stretch under supervision for each of six major leg muscle groups during every warm-up. The control group did not stretch.
                333 lower-limb injuries were recorded during the training period, including 214 soft-tissue injuries. There were 158 injuries in the stretch group and 175 in the control group. There was no significant effect of preexercise stretching on all-injuries risk (hazard ratio [HR] = 0.95, 95% CI 0.77-1.18), soft-tissue injury risk (HR = 0.83, 95% CI 0.63-1.09), or bone injury risk (HR = 1.22, 95% CI 0.86-1.76). Fitness (20-m progressive shuttle run test score), age, and enlistment date all significantly predicted injury risk (P < 0.01 for each), but height, weight, and body mass index did not.
                A typical muscle stretching protocol performed during preexercise warm-ups does not produce clinically meaningful reductions in risk of exercise-related injury in army recruits. Fitness may be an important, modifiable risk factor.


Title 4:
A prospective study of the effect of foot orthoses composition and fabrication on comfort and the incidence of overuse injuries.
Abstract 4:
Foot orthoses are widely prescribed both to treat existing pathological conditions and to prevent overuse injuries, but little is known about the effect of their material composition and fabrication technique on patient comfort and the incidence of overuse injuries.
                The acceptance rates and comfort scores of soft custom, soft prefabricated, semirigid biomechanical, and semirigid prefabricated orthoses and their effect on the incidence of stress fractures, ankle sprains, and foot problems were studied in a prospective, randomized, single-blinded clinical trial among 874 infantry recruits during basic training.
                A statistically significantly lower number of recruits given soft prefabricated orthoses (53%) finished basic training in their assigned devices than in the soft custom group (72%), in the semirigid biomechanical group (75%), and in the semirigid prefabricated group (82%) (p = .003). For recruits who finished training in their assigned orthoses, the soft custom (3.54) and soft prefabricated (3.43) orthoses had significantly higher comfort scores than the semirigid biomechanical (3.23) and prefabricated (3.17) orthoses, (p = .0001). There was no statistically significant difference in the incidence of stress fractures, ankle sprains, or foot problems between recruits using the different types of orthoses.
                These findings suggest that if a foot orthosis is being dispensed as prophylaxis for overuse injuries in an active, healthy population, there is little justification for prescribing semirigid biomechanical orthoses. Their cost is high compared to other types of orthoses, without an advantage in comfort or a reduction in stress fractures, ankle sprains, and foot problems.


Title 5:
A prospective study of the effect of a shock-absorbing orthotic device on the incidence of stress fractures in military recruits.
Abstract 5:
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.


Title 6:
Relationship between footwear comfort of shoe inserts and anthropometric and sensory factors.
Abstract 6:
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.


Title 7:
Does calcium supplementation prevent bone stress injuries? A clinical trial.
Abstract 7:
This study investigated the effect of calcium supplementation in preventing bone stress injuries. Healthy male military recruits (N = 1,398) served as subjects, of which 247 were randomly allocated to an experimental group (E) while 1,151 served as a control group (C). For 9 weeks both groups wore the same footwear and had the same physical training program. The baseline dietary intake of calcium in 50 randomly selected subjects of each group was assessed using a 24-hr dietary record. The E group received a daily calcium supplement while the C group did not. Injuries were monitored in all subjects by a panel of doctors who followed specific diagnostic criteria. The mean weekly injury incidence for all overuse injuries, but specifically tibial stress syndrome and stress fractures, was similar in both groups. Mean baseline daily dietary calcium intake was above 800 mg in both subgroups. This study demonstrated that large-scale calcium supplementation (500 mg/day) beyond usual dietary intake did not influence the risk of developing bone stress injuries during a 9-wk physical training program in these young military recruits.


Title 8:
Prevention of common overuse injuries by the use of shock absorbing insoles. A prospective study.
Abstract 8:
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.


Title 9:
Prevention of lower extremity stress fractures: a controlled trial of a shock absorbent insole.
Abstract 9:
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.


Title 10:
A prospective study on the management of shin splints.
Abstract 10:
nan


Title 11:
Effects of ankle dorsiflexion range and pre-exercise calf muscle stretching on injury risk in Army recruits.
Abstract 11:
This study investigated effects of ankle dorsiflexion range and pre-exercise calf muscle stretching on relative risk of selected injuries in 1093 male Army recruits undertaking 12 weeks of intensive training. Prior to training, ankle dorsiflexion range was measured and recruits were allocated to stretch and control groups using a quasi-random procedure. The stretch group stretched calf muscles under supervision prior to all intense exercise. The control group stretched upper limb muscles instead. Forty-eight injuries were recorded. Survival analysis indicated that ankle dorsiflexion range was a strong predictor of injury (p = 0.03). Definitive evidence of an effect of stretching on injury risk was not found (p = 0.76), but the sample size may have been insufficient to detect such an effect.
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.