human
***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: Among a population of r and omly selected US Marine Corps recruits at Marine Corps Recruit Depot , San Diego , California , the authors developed a screening tool to identify individuals at high risk for lower extremity stress fracture when beginning a rigorous physical training program .  The screening tool was developed among 1,286 recruits , then tested and refined among 1,078 additional recruits . The refined algorithm , consisting of five physical activity questions and a 1.5-mi ( 2.4-km ) run time , revealed that 21.6 % of " high risk " subjects suffered more than three times as many stress fractures as " low risk " subjects . These data suggest that risk of stress fracture during rigorous physical training is increased by poor physical fitness and low levels of physical activity prior to their entry into the program Background Military service in Finl and is compulsory for all male citizens and annually about 80 % of 19-year-old men enter into the service . The elevated risk for many chronic diseases and loss of function among those who are inactive and unfit can be often detected already in youth . On the other h and , activity-induced injuries among young are true public health issue . The purpose of the present prospect i ve cohort follow-up study was to evaluate predictive associations between acute or overuse injuries and their various intrinsic risk factors . Methods Four successive cohorts of conscripts who formed a representative sample of Finnish young men were followed for 6 months . At the beginning of the service , the risk factors of injuries were measured and recorded and then the acute and overuse injuries treated at the garrison clinic were identified . Predictive associations between injuries and their risk factors were examined by multivariate Cox ’s proportional hazard models . Results Of the 1411 participants , 27 % sustained an acute injury and 51 % suffered from overuse injury . Concerning acute injuries , highest risk for severe injuries were detected among conscripts with low fitness level in both the st and ing long-jump and push-up tests ( hazard rate , HR=5.9 ; 95 % CI : 1.6‒21.3 ) . A history of good degree in school sports was not a protective factor against acute injuries . High waist circumference and , on the other h and , being underweight according to BMI increased the HR for overuse injuries . Brisk leisure time physical activity before military entry was a protective factor against overuse injuries . Poor result in Cooper ’s test was a warning signal of elevated risk of overuse injuries . Conclusion We confirmed previous findings that low level of physical fitness is predictor for musculoskeletal injuries during intensive physical training . The U-shaped relationship between body composition and overuse injuries was noticed indicating that both obesity and underweight are risk factors for overuse injuries . Persons with excellent sports skills according to their earlier degrees in school sports had similar HR for acute injuries than those with poorer degrees . This indicates that school-age sports skills and fitness do not carry far and therefore preventive programmes are needed to prevent activity-induced injuries PURPOSE To assess the relationships between player characteristics ( including age , playing experience , ethnicity , and physical fitness ) and in-season injury in elite Australian football . DESIGN Single-cohort , prospect i ve , longitudinal study . METHODS Player characteristics ( height , body mass , age , experience , ethnicity , playing position ) , preseason fitness ( 6-min run , 40-m sprint , 6 × 40-m sprint , vertical jump ) , and in-season injury data were collected over 4 seasons from 1 professional Australian football club . Data were analyzed for 69 players , for a total of 3879 player rounds and 174 seasons . Injury risk ( odds ratio [ OR ] ) and injury severity ( matches missed ; rate ratio [ RR ] ) were assessed using a series of multilevel univariate and multivariate hierarchical linear models . RESULTS A total of 177 injuries were recorded with 494 matches missed ( 2.8±3.3 matches/injury ) . The majority ( 87 % ) of injuries affected the lower body , with hamstring ( 20 % ) and groin/hip ( 14 % ) most prevalent . Nineteen players ( 28 % ) suffered recurrent injuries . Injury incidence was increased in players with low body mass ( OR=0.887 , P=.005 ) , with poor 6-min-run performance ( OR=0.994 , P=.051 ) , and playing as forwards ( OR=2.216 , P=.036 ) . Injury severity was increased in players with low body mass ( RR=0.892 , P=.008 ) , tall stature ( RR=1.131 , P=.002 ) , poor 6-min-run ( RR=0.990 , P=.006 ) , and slow 40-m-sprint ( RR=3.963 , P=.082 ) performance . CONCLUSIONS The potential to modify intrinsic risk factors is greatest in the preseason period , and improvements in aerobic-running fitness and increased body mass may protect against in-season injury in elite Australian football BACKGROUND Stress fractures and other musculoskeletal injuries are major sources of morbidity among female military trainees . Several risk factors have been postulated , particularly pre-existing fitness , usually assessed with post-entry run time for ≥ 1.0 mile . PURPOSE Physical fitness is not formally evaluated prior to Army entry . If a valid and simple test that identified women at increased risk of stress fracture were available and could be applied prior to entry , it would facilitate cost-benefit studies of deferral or interventions . These analyses were undertaken to determine if a 5-minute step test conducted before entry identified women at increased risk . METHODS A prospect i ve study was conducted of weight-qualified women entering the Army in 2005 - 2006 , with analyses completed in 2011 . At the pre-entry examination , information was collected on age , BMI , smoking , race , and activity level . Everyone took the step test . All outpatient medical encounters were captured , and stress fractures and other musculoskeletal injuries identified . Women with stress fractures and those with other musculoskeletal injuries were evaluated separately . RESULTS 1568 women were included in the study ; 109 developed stress fractures and 803 other musculoskeletal injury . Women who failed the step test had a 76 % higher stress fracture incidence and a 35 % higher incidence of other musculoskeletal injuries . There was effect modification between age and test failure for stress fracture . CONCLUSIONS A step test that can be administered before military entry identifies women with increased incidence of stress fracture and other musculoskeletal injury . This test could be used pre-entry to defer or target high-risk recruits for tailored fitness training before or after military entrance Background The injury risk in football is high , but little is known about causes of injury . Purpose To identify risk factors for football injuries using a multivariate model . Study Design Prospect i ve cohort study . Methods Participants were 306 male football players from the two highest divisions in Icel and . Before the 1999 football season started , the following factors were examined : height , weight , body composition , flexibility , leg extension power , jump height , peak O2 uptake , joint stability , and history of previous injury . Injuries and player exposure were recorded throughout the competitive season . Results Older players were at higher risk of injury in general ( odds ratio [ OR ] = 1.1 per year , P = 0.05 ) . For hamstring strains , the significant risk factors were age ( OR = 1.4 [ 1 year ] , P < 0.001 ) and previous hamstring strains ( OR = 11.6 , P < 0.001 ) . For groin strains , the predictor risk factors were previous groin strains ( OR = 7.3 , P = 0.001 ) and decreased range of motion in hip abduction ( OR = 0.9 [ 1 ° ] , P = 0.05 ) . Previous injury was also identified as a risk factor for knee ( OR = 4.6 ) and ankle sprains ( OR = 5.3 ) . Conclusions Age and previous injury were identified as the main risk factors for injury among elite football players from Icel and PURPOSE The purpose of this prospect i ve study was to examine rates and risk factors for overuse injuries among 824 women during Marine Corps Recruit Depot basic training at Parris Isl and , SC , in 1999 . METHODS Data collected included training day exposures ( TDE ) , baseline performance on a st and ardized 1.5-mile timed run , and a pretraining question naire highlighting exercise and health habits . The women were followed during training for occurrence of stress fracture and other lower-extremity overuse injury . RESULTS There were 868 lower-extremity overuse injuries for an overall injury rate of 12.6/1000 TDE . Rates for initial and subsequent injury were 8.7/1000 and 20.7/1000 TDE , respectively . There were 66 confirmed lower-extremity stress fractures among 56 ( 6.8 % ) women ( 1.0/1000 TDE ) . Logistic regression modeling indicated that low aerobic fitness ( a slower time on the timed run ( > 14.4 min ) ) , no menses in six or more consecutive months during the past year , and less than 7 months of lower-extremity weight training were significantly associated with stress fracture incidence . Self-rated fair-poor fitness at baseline was the only variable significantly associated with other non-stress fracture overuse injury during basic training . CONCLUSIONS Among this sample of women , the risk of lower-extremity overuse injury was high , with a twofold risk of subsequent injury . The results suggest that stress fracture injury might be decreased if women entered training with high aerobic fitness and participated frequently in lower-extremity strength training . Furthermore , women reporting a history of menstrual irregularity at their initial medical exam may require closer observation during 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 r and omly 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 question naire , existing data bases , 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 prospect i ve 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 Physical training-related injuries are common among army recruits and other vigorously active population s , but little is known about their causation . To identify intrinsic risk factors , we prospect ively measured 391 army trainees . For 8 weeks of basic training , 124 men and 186 women ( 79.3 % ) were studied . They answered question naires on past activities and sports participa tion , and were measured for height , weight , and body fat percentage ; 71 % of the subjects took an initial army physical training test . Women had a significantly higher incidence of time-loss injuries than men , 44.6 % com pared with 29.0 % . During training , more time-loss in juries occurred among the 50 % of the men who were slower on the mile run , 29.0 % versus 0.0 % . Slower women were likewise at greater risk than faster ones , 38.2 % versus 18.5 % . Men with histories of inactivity and with higher body mass index were at greater injury risk than other men , as were the shortest women . We conclude that female gender and low aerobic fitness measured by run times are risk factors for training injuries in army trainees , and that other factors such as prior activity levels and stature may affect men and women differently Abstract The aim of this study was to investigate changes in running mechanics and spring-mass behaviour with fatigue induced by 5-hour hilly running ( 5HHR ) . Running mechanics were measured pre- and post-5HHR at 10 , 12 and 14 km · h-1 on an instrumented treadmill in eight ultramarathon runners , and sample d at 1000 Hz for 10 consecutive steps . Contact ( tc ) and aerial ( ta ) times were determined from ground reaction force ( GRF ) signals and used to compute step frequency ( f ) . Maximal GRF , loading rate , downward displacement of the centre of mass ( Δz ) , and leg length change ( ΔL ) during the support phase were determined and used to compute both vertical ( Kvert ) and leg ( Kleg ) stiffness . A significant decrease in tc was observed at 12 and 14 km · h-1 result ing in an increase of f at all speeds . Duty factor and Fmax significantly decreased at 10 km · h-1 . A significant increase in Kvert and Kleg was observed at all running speeds with significant decreases in  
    Output:
    
agent
Primary findings indicate that there is ( a ) strong evidence that poor performance on a set distance run for time is a predictor for MSK-I risk in both genders ; ( b ) strong evidence that poor performance on timed shuttle runs is a predictor for MSK-I risk in males ; ( c ) moderate evidence in males and limited evidence in females that poor performance on a timed step test is a predictor of MSK-I risk ; and ( d ) limited or insufficient evidence that poor performance on the Cooper run test , maximal and submaximal aerobic grade d exercise tests , and the Conconi test are predictors of MSK-I risk in males or females or both .
Several measures of CRE are risk factors for training-related MSK-I in military and civilian athletic population s , indicating that CRE may be an important measure for MSK-I risk stratification
***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: Among a population of r and omly selected US Marine Corps recruits at Marine Corps Recruit Depot , San Diego , California , the authors developed a screening tool to identify individuals at high risk for lower extremity stress fracture when beginning a rigorous physical training program .  The screening tool was developed among 1,286 recruits , then tested and refined among 1,078 additional recruits . The refined algorithm , consisting of five physical activity questions and a 1.5-mi ( 2.4-km ) run time , revealed that 21.6 % of " high risk " subjects suffered more than three times as many stress fractures as " low risk " subjects . These data suggest that risk of stress fracture during rigorous physical training is increased by poor physical fitness and low levels of physical activity prior to their entry into the program Background Military service in Finl and is compulsory for all male citizens and annually about 80 % of 19-year-old men enter into the service . The elevated risk for many chronic diseases and loss of function among those who are inactive and unfit can be often detected already in youth . On the other h and , activity-induced injuries among young are true public health issue . The purpose of the present prospect i ve cohort follow-up study was to evaluate predictive associations between acute or overuse injuries and their various intrinsic risk factors . Methods Four successive cohorts of conscripts who formed a representative sample of Finnish young men were followed for 6 months . At the beginning of the service , the risk factors of injuries were measured and recorded and then the acute and overuse injuries treated at the garrison clinic were identified . Predictive associations between injuries and their risk factors were examined by multivariate Cox ’s proportional hazard models . Results Of the 1411 participants , 27 % sustained an acute injury and 51 % suffered from overuse injury . Concerning acute injuries , highest risk for severe injuries were detected among conscripts with low fitness level in both the st and ing long-jump and push-up tests ( hazard rate , HR=5.9 ; 95 % CI : 1.6‒21.3 ) . A history of good degree in school sports was not a protective factor against acute injuries . High waist circumference and , on the other h and , being underweight according to BMI increased the HR for overuse injuries . Brisk leisure time physical activity before military entry was a protective factor against overuse injuries . Poor result in Cooper ’s test was a warning signal of elevated risk of overuse injuries . Conclusion We confirmed previous findings that low level of physical fitness is predictor for musculoskeletal injuries during intensive physical training . The U-shaped relationship between body composition and overuse injuries was noticed indicating that both obesity and underweight are risk factors for overuse injuries . Persons with excellent sports skills according to their earlier degrees in school sports had similar HR for acute injuries than those with poorer degrees . This indicates that school-age sports skills and fitness do not carry far and therefore preventive programmes are needed to prevent activity-induced injuries PURPOSE To assess the relationships between player characteristics ( including age , playing experience , ethnicity , and physical fitness ) and in-season injury in elite Australian football . DESIGN Single-cohort , prospect i ve , longitudinal study . METHODS Player characteristics ( height , body mass , age , experience , ethnicity , playing position ) , preseason fitness ( 6-min run , 40-m sprint , 6 × 40-m sprint , vertical jump ) , and in-season injury data were collected over 4 seasons from 1 professional Australian football club . Data were analyzed for 69 players , for a total of 3879 player rounds and 174 seasons . Injury risk ( odds ratio [ OR ] ) and injury severity ( matches missed ; rate ratio [ RR ] ) were assessed using a series of multilevel univariate and multivariate hierarchical linear models . RESULTS A total of 177 injuries were recorded with 494 matches missed ( 2.8±3.3 matches/injury ) . The majority ( 87 % ) of injuries affected the lower body , with hamstring ( 20 % ) and groin/hip ( 14 % ) most prevalent . Nineteen players ( 28 % ) suffered recurrent injuries . Injury incidence was increased in players with low body mass ( OR=0.887 , P=.005 ) , with poor 6-min-run performance ( OR=0.994 , P=.051 ) , and playing as forwards ( OR=2.216 , P=.036 ) . Injury severity was increased in players with low body mass ( RR=0.892 , P=.008 ) , tall stature ( RR=1.131 , P=.002 ) , poor 6-min-run ( RR=0.990 , P=.006 ) , and slow 40-m-sprint ( RR=3.963 , P=.082 ) performance . CONCLUSIONS The potential to modify intrinsic risk factors is greatest in the preseason period , and improvements in aerobic-running fitness and increased body mass may protect against in-season injury in elite Australian football BACKGROUND Stress fractures and other musculoskeletal injuries are major sources of morbidity among female military trainees . Several risk factors have been postulated , particularly pre-existing fitness , usually assessed with post-entry run time for ≥ 1.0 mile . PURPOSE Physical fitness is not formally evaluated prior to Army entry . If a valid and simple test that identified women at increased risk of stress fracture were available and could be applied prior to entry , it would facilitate cost-benefit studies of deferral or interventions . These analyses were undertaken to determine if a 5-minute step test conducted before entry identified women at increased risk . METHODS A prospect i ve study was conducted of weight-qualified women entering the Army in 2005 - 2006 , with analyses completed in 2011 . At the pre-entry examination , information was collected on age , BMI , smoking , race , and activity level . Everyone took the step test . All outpatient medical encounters were captured , and stress fractures and other musculoskeletal injuries identified . Women with stress fractures and those with other musculoskeletal injuries were evaluated separately . RESULTS 1568 women were included in the study ; 109 developed stress fractures and 803 other musculoskeletal injury . Women who failed the step test had a 76 % higher stress fracture incidence and a 35 % higher incidence of other musculoskeletal injuries . There was effect modification between age and test failure for stress fracture . CONCLUSIONS A step test that can be administered before military entry identifies women with increased incidence of stress fracture and other musculoskeletal injury . This test could be used pre-entry to defer or target high-risk recruits for tailored fitness training before or after military entrance Background The injury risk in football is high , but little is known about causes of injury . Purpose To identify risk factors for football injuries using a multivariate model . Study Design Prospect i ve cohort study . Methods Participants were 306 male football players from the two highest divisions in Icel and . Before the 1999 football season started , the following factors were examined : height , weight , body composition , flexibility , leg extension power , jump height , peak O2 uptake , joint stability , and history of previous injury . Injuries and player exposure were recorded throughout the competitive season . Results Older players were at higher risk of injury in general ( odds ratio [ OR ] = 1.1 per year , P = 0.05 ) . For hamstring strains , the significant risk factors were age ( OR = 1.4 [ 1 year ] , P < 0.001 ) and previous hamstring strains ( OR = 11.6 , P < 0.001 ) . For groin strains , the predictor risk factors were previous groin strains ( OR = 7.3 , P = 0.001 ) and decreased range of motion in hip abduction ( OR = 0.9 [ 1 ° ] , P = 0.05 ) . Previous injury was also identified as a risk factor for knee ( OR = 4.6 ) and ankle sprains ( OR = 5.3 ) . Conclusions Age and previous injury were identified as the main risk factors for injury among elite football players from Icel and PURPOSE The purpose of this prospect i ve study was to examine rates and risk factors for overuse injuries among 824 women during Marine Corps Recruit Depot basic training at Parris Isl and , SC , in 1999 . METHODS Data collected included training day exposures ( TDE ) , baseline performance on a st and ardized 1.5-mile timed run , and a pretraining question naire highlighting exercise and health habits . The women were followed during training for occurrence of stress fracture and other lower-extremity overuse injury . RESULTS There were 868 lower-extremity overuse injuries for an overall injury rate of 12.6/1000 TDE . Rates for initial and subsequent injury were 8.7/1000 and 20.7/1000 TDE , respectively . There were 66 confirmed lower-extremity stress fractures among 56 ( 6.8 % ) women ( 1.0/1000 TDE ) . Logistic regression modeling indicated that low aerobic fitness ( a slower time on the timed run ( > 14.4 min ) ) , no menses in six or more consecutive months during the past year , and less than 7 months of lower-extremity weight training were significantly associated with stress fracture incidence . Self-rated fair-poor fitness at baseline was the only variable significantly associated with other non-stress fracture overuse injury during basic training . CONCLUSIONS Among this sample of women , the risk of lower-extremity overuse injury was high , with a twofold risk of subsequent injury . The results suggest that stress fracture injury might be decreased if women entered training with high aerobic fitness and participated frequently in lower-extremity strength training . Furthermore , women reporting a history of menstrual irregularity at their initial medical exam may require closer observation during 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 r and omly 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 question naire , existing data bases , 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 prospect i ve 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 Physical training-related injuries are common among army recruits and other vigorously active population s , but little is known about their causation . To identify intrinsic risk factors , we prospect ively measured 391 army trainees . For 8 weeks of basic training , 124 men and 186 women ( 79.3 % ) were studied . They answered question naires on past activities and sports participa tion , and were measured for height , weight , and body fat percentage ; 71 % of the subjects took an initial army physical training test . Women had a significantly higher incidence of time-loss injuries than men , 44.6 % com pared with 29.0 % . During training , more time-loss in juries occurred among the 50 % of the men who were slower on the mile run , 29.0 % versus 0.0 % . Slower women were likewise at greater risk than faster ones , 38.2 % versus 18.5 % . Men with histories of inactivity and with higher body mass index were at greater injury risk than other men , as were the shortest women . We conclude that female gender and low aerobic fitness measured by run times are risk factors for training injuries in army trainees , and that other factors such as prior activity levels and stature may affect men and women differently Abstract The aim of this study was to investigate changes in running mechanics and spring-mass behaviour with fatigue induced by 5-hour hilly running ( 5HHR ) . Running mechanics were measured pre- and post-5HHR at 10 , 12 and 14 km · h-1 on an instrumented treadmill in eight ultramarathon runners , and sample d at 1000 Hz for 10 consecutive steps . Contact ( tc ) and aerial ( ta ) times were determined from ground reaction force ( GRF ) signals and used to compute step frequency ( f ) . Maximal GRF , loading rate , downward displacement of the centre of mass ( Δz ) , and leg length change ( ΔL ) during the support phase were determined and used to compute both vertical ( Kvert ) and leg ( Kleg ) stiffness . A significant decrease in tc was observed at 12 and 14 km · h-1 result ing in an increase of f at all speeds . Duty factor and Fmax significantly decreased at 10 km · h-1 . A significant increase in Kvert and Kleg was observed at all running speeds with significant decreases in  
    Output:
    