***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Eighty-seven male inmates from a state prison and 70 inmates from a county jail volunteered as subjects . The subjects , age 20 to 35 yrs , were assigned r and omly into a control or exercise group . Their Vo2max and treadmill performance values were determined before and after a 20 week jogging program . Training intensity was between 85 and 90 percent of maximum heart rate and involved workouts 3 days/week for 15 , 30 , or 45-min duration at the state prison and for 30-min 1 , 3 , or 5 days/week at the country jail . Cardiorespiratory fitness improved in direct proportion to frequency and duration of training . Injury , occurred in 22 % , 24 % and 54 % of the 15 , 30 , and 45-min duration groups and in 0 % , 12 % , and 39 % of the 1 , 3 , and 5-day/week groups , respectively . Attrition result ing from injury occurred in 0 % , 0 % , and 17 % and in 0 % , 4 % , and 6 % of the same respective groups . Attrition due to lack of interest was similar for all training groups ( 25 % ) , but was significantly lower in the control groups ( 10 % ) . Although the results showed a greater increase in cardiorespiratory fitness for the 45-min duration and 5-day/week groups , these programs are not recommened for beginning joggers because of the significantly greater percent of injuries In a r and omized prospect i ve study among 390 recruits , the hypothesis that improved shoe shock attenuation could lessen the incidence of overuse injuries was tested . During the 14 weeks of training , 90 % of the recruits sustained overuse injuries .  Recruits training in a modified basketball shoe had a statistically significant lower incidence of metatarsal stress fractures and foot overuse injuries , compared with st and ard infantry boots , but their overall incidence of overuse injuries was not reduced . The effect of improved shoe shock attenuation was limited to those overuse injuries result ing from vertical impact loads Three hundred fifty male recruits were r and omly allocated to either the st and ard recruit training program ( N = 180 ) or substituted a weighted-march activity for all formal run periods ( N = 170 ) in the physical training program . All injuries were seen at a single medical facility , and the cause , location , and severity of injury were recorded in the medical documents . Lower-limb injuries constituted 79.8 % of all Run injuries and 61.1 % of all Walk injuries . Foot ( 18.9 % ) , knee ( 16.7 % ) , ankle ( 13.3 % ) , and shoulder ( 8.9 % ) were the most common sites of injury in the Walk group . In the Run group , the most common sites were knee ( 32.1 % ) , ankle ( 18.3 % ) , foot ( 11.9 % ) , and shin ( 7.3 % ) . There were two stress fractures ( tibial ) in the Run group and none in the Walk group , giving the Run group an incidence of 1.1 % . There were 10 medical discharges  in the Walk group and 16 in the Run group . Ten ( 62.5 % ) of the Run and 2 ( 20 % ) of the Walk discharges were due to lower-limb causes . Of these , only 1 ( 10 % ) of the Walk and 4 ( 25 % ) of the Run injuries were not considered to be pre-existing conditions . Marching ( 30.0 % ) , physical training ( 25.5 % ) , and the obstacle course ( 11.1 % ) were the most frequent causes of injury in the Walk group . In the Run group , the leading causes were running ( 36.6 % ) , physical training ( 19.2 % ) , and the obstacle course ( 14.6 % ) . Running was the major cause of knee injury in the Run group ( 17/35 ) , whereas physical training was the major cause of knee injury in the Walk group ( 5/15 ) . Running was also the major cause of other lower-limb injuries in the Run group ( 19/58 ) , whereas marching was the major cause in the Walk group ( 19/50 ) . Lower-limb injuries were more frequent in the Run group , with running cited as the major cause of these injuries 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 r and omly selected to wear shock absorbing heel inserts ( SAH ) in the 5 day-tournament , while 43 referees were the control group .  A daily question naire 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 Three hundred fifty male recruits were r and omly allocated to either the st and ard recruit training program ( N = 180 ) or substituted a weighted march activity for all running periods in the physical training program ( N = 170 ) . There were no other differences in the formal training program . The incidence of injury was 37.6 and 46.6 % in the walk and run groups , respectively . The rate of injury was 52.9/100 recruits in the walk group and 61.7/100 in the run group . The exposure incidence was 12.8/1,000 hours of physical training in the walk group and 14.9/1,000 hours in the run group . There was no statistically significantly difference in the total number of injured recruits in the two groups ( 64 vs. 85 , chi(2 ) = 2.90 , p = 0.09 , relative risk [ RR ] = 1.24 ) . There were , however , significantly more lower-limb ( 43 vs. 75 , chi(2 ) = 9.77 , p = 0.0018 , RR = 1.65 ) and knee injuries ( 15 vs. 35 , chi(2 ) = 6.54 , p = 0.011 , RR = 2.14 ) in the Run group . Lower-limb injuries constituted 79.8 % of all Run injuries and 61.1 % of all Walk injuries . Injuries in the Run group produced more morbidity , with nearly double the number of days of restriction , hospitalization , and not fit for duty . St and ardized morbidity rates showed an average of 5.4 days of restriction per injury in the Run group and 3.96 days of restriction per injury in the Walk group . Reduction of running distance in the physical training program result ed in significant reductions in both the incidence of lower-limb injury and the overall severity of injury The purpose of this intervention study was to prove that increasing flexibility of the hamstring musculotendinous unit would decrease the number of lower extremity overuse injuries that occur in military infantry basic trainees . Two different companies going through basic training at the same time were used . Hamstring flexibility was checked at the beginning and at the end of the 13-week infantry basic training course . The control company ( N 148 ) proceeded through normal basic training . The intervention company ( N 150 ) followed the same program but added three hamstring stretching sessions to their already scheduled fitness program . All subsequent lower extremity overuse injuries were recorded through the troop medical clinic . Hamstring flexibility increased significantly in the intervention group compared with the control group . The number of injuries was also significantly lower in the intervention group . Forty-three injuries occurred in the control group for an incidence rate of 29.1 % , compared with 25 injuries in the intervention group for an incidence rate of 16.7 % . Thus , in this study , the number of lower extremity overuse injuries was significantly lower in infantry basic trainees with increased hamstring flexibility Our prospect i ve study evaluates the use of a knee brace with a silicon patellar support ring as a method of preventing anterior knee pain from developing in young persons undergoing strenuous physical exercise . We studied 60 young athletes , who qualified for a strenu ous physical training course and who had not suffered from anterior knee pain previously . Twenty-seven sub jects were in the brace group and 33 were in the nonbrace control group .  The incidence of anterior knee pain syndrome increased with the intensity of exertion as the study progressed ; i.e. , subjects ran 6 km in the 1 st week , gradually increasing each week up to 42 km/week at the 8th week . Yet , there was a significant reduction in the incidence of the syndrome at the end of the study in male athletes who had applied the braces before exercise sessions and in the brace group as a whole , compared with the control group . Prophylactic use of the brace , as described , did not reduce the ability of the athletes who wore braces to improve their physical fitness parameters in response to exercise . These data indicate that the use of a brace may be an effective way to prevent the development of anterior knee pain syndromes in persons participating in strenuous and intensive physical exercise 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 r and omly 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 classi fied 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 , re spectively . 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 < 0.05 ) in the experimental group . The mean incidence of stress fractures was lower in the experimental group but not significantly so ( 0.05 < P < 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 The purpose of this study was to evaluate the effect of a health education intervention on  running injuries .  The intervention consisted of information on , and the sub sequent performance of , st and ardized warm-up , cool- down , and stretching exercises .  Four hundred twenty- one male recreational runners were matched for age , weekly running distance , and general knowledge of preventing sports injuries . They were r and omly split into an intervention and a control group : 167 control and 159 intervention subjects participated throughout the study . During the 16-week study , both groups kept a daily diary on their running distance and time , and reported all injuries . In addition , the intervention group was asked to note compliance with the st and ardized program . At the end of the study period , knowledge and attitude were again measured . There were 23 injuries in the control group and 26 in the intervention group . Injury incidence for control and intervention sub jects was 4.9 and 5.5 running injuries per 1000 hours , respectively . The intervention was not effective in re ducing the number of running injuries ; it proved signifi cantly effective ( P < 0.05 ) in improving specific knowl edge of warm-up and cool-down techniques in the intervention group . This positive change can perhaps be regarded as a first step on the way to a change of behavior , which may eventually lead to a reduction of running injuries PURPOSE This study investigated the effect of muscle stretching during warm-up on the risk of exercise-related injury . METHODS 1538 male army recruits were r and omly 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 . RESULTS 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 . CONCLUSION A typical muscle stretching protocol performed during preexercise warm-ups does not produce clinical ly meaningful reductions in risk of exercise-related injury  in army recruits . Fitness may be an important , modifiable risk factor 
    Output:
    
RESULTS Exposure to a high training load ( duration , frequency , or running distance ) increases the risk of injury , and thus modification of the training schedule can reduce the incidence of injury .
Wearing a knee brace with a patellar support ring may be effective in the prevention of anterior knee pain caused by running .
This review provides evidence for the effectiveness of the modification of training schedules in reducing lower limb soft tissue running injuries .