***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: PURPOSE Exercise-related lower-leg pain ( ERLLP ) is a common chronic sports injury . In clinical practice , deviant gait biomechanics are frequently considered to play a role in the development of ERLLP , although there is scarce scientific evidence that gait-related variables predispose athletes to this injury . The purpose of this study was to examine prospect ively the gait-related risk factors for ERLLP during shod running in a young , physically active population . METHODS The gait pattern during shod running of 400 physical education students was evaluated at the beginning of their academic study . This was accomplished by means of plantar pressure measurements and 3D gait kinematics . After this evaluation , the same sports physician registered all sports injuries during this study . RESULTS During the follow-up period , 46 subjects developed ERLLP , of whom 29 subjects had bilateral complaints . Thus , 75 symptomatic lower legs ( 35 left and 40 right ) were classified into the ERLLP group . Bilateral feet of 167 subjects who sustained no injuries at the lower extremities served as the referent group . Cox regression analysis revealed that subjects who will develop ERLLP have an altered running pattern compared with the referent subjects . More specifically , these subjects showed a significantly increased pronation excursion , accompanied by more pressure underneath the medial side of the foot , a delayed maximal eversion , and an accelerated reinversion . CONCLUSION The findings of this study suggest that altered gait biomechanics during shod running play a role in the genesis of ERLLP and , thus , should be considered in prevention and rehabilitation of this pathology STUDY DESIGN Prospect i ve cohort design . OBJECTIVES To determine in a sample of collegiate cross-country athletes ( 1 ) the percentage of athletes with history of exercise-related leg pain ( ERLP ) associated with running , ( 2 ) the incidence of ERLP during 1 season , ( 3 ) if factors including years of collegiate running , training distance , and gender are associated with ERLP , and ( 4 ) if there is a relationship between foot type and ERLP . BACKGROUND ERLP is a common overuse pain syndrome , but little evidence exists regarding the prevalence , incidence , and risk factors . METHODS AND MEASURES Eighty-eight collegiate cross-country athletes ( 44 male , 44 female ) from 5 Midwest universities consented to participate , Prior to the season , athletes completed a question naire and 3 measures of foot type were performed : navicular drop , medial longitudinal arch angle , and visual assessment of foot type . Athletes completed a postseason question naire regarding the season incidence of ERLP Statistical analyses of differences ( t test , proportion test ) and relationships ( chi-square , relative risk ) were conducted . RESULTS Prior to the season , 60 of the 88 athletes ( 68 % ) reported a history of ERLP with bilateral medial leg pain the most common ERLP presentation . Over 50 % of the athletes with a history of ERLP reported that the pain had interfered with cross-country participation . Of the 67 postseason respondents , 38.8 % reported ERLP incidence during the season . Most athletes ( 80.8 % ) who reported season incidence of ERLP had a previous history of ERLP There were no differences between athletes with and without a history of ERLP or season incidence of ERLP regarding years of collegiate running , training distance , gender , and foot measures . CONCLUSION ERLP history and season incidence was common among these cross-country athletes . The only risk factor identified for season incidence of ERLP was a history of ERLP STUDY DESIGN Predictive correlational study . OBJECTIVES To identify the incidence of medial tibial stress syndrome ( MTSS ) in a group of high school cross-country runners and to determine if a relationship exists between lower extremity structural measures and the incidence of MTSS . BACKGROUND Medial tibial stress syndrome is an overuse injury that occurs in long-distance runners . Literature exists that implicates structural deformity as a contributor to MTSS , but no studies have developed a predictive model . METHODS AND MEASURES We measured 125 high school cross-country runners for tibiofibular varum , resting calcaneal position during stance , and gastrocnemius length . Runners developing MTSS over an 8-week period were placed in the injured group ( 2 men , 13 women ; age 15.3 years 1.0 ) , and 21 r and omly selected uninjured runners were placed in the uninjured group ( 13 men , 8 women ; age 15.7 years + /-1.5 ) . Navicular drop was measured for runners in both groups . Reliability of measures was determined using an intraclass correlation coefficient ( ICC 3,1 ) . Paired t tests were used to compare the injury and noninjury groups . A logistic regression analysis was used to establish if the descriptive data could accurately predict the development of MTSS . RESULTS Paired t tests showed a significant difference in navicular drop test measures between the injured ( 6.8 mm 3.7 ) and noninjured ( 3.6 mm 3.3 ) groups . Logistic regression analysis revealed navicular drop test measurements and sex correctly identified athletes who developed MTSS with 76 % accuracy . CONCLUSION Our study supported the hypothesis that a pronatory foot type is related to MTSS . The combination of sex and navicular drop test measures provides an accurate prediction for the development of MTSS . Clinical measures that identify biomechanical risk factors for MTSS may allow prevention or early intervention Objective : To investigate in a military setting the potential role of intrinsic biomechanical and anthropometric risk factors for , and the incidence of , exertional medial tibial pain ( EMTP ) . Methods : A prospect i ve clinical outcome study in a cohort of 122 men and 36 women at the Australian Defence Force Academy . Each cadet underwent measurements of seven intrinsic variables : hip range of motion , leg length discrepancy , lean calf girth , maximum ankle dorsiflexion range , foot type , rear foot alignment , and tibial alignment . Test – retest reliability was undertaken on each variable . A physician recorded any cadet presenting with diagnostic criteria of EMTP . Records were analysed at 12 months for EMTP presentation and for military fitness test results . Results : 23 cadets ( 12 men , 11 women ) met the criteria for EMTP after 12 months , with a cross gender ( F/M ) odds ratio of 3.1 . In men , both internal and external range of hip motion was greater in those with EMTP : left internal ( 12 ° , p = 0.000 ) , right internal ( 8 ° , p = 0.014 ) , left external ( 8 ° , p = 0.042 ) , right external ( 9 ° , p = 0.026 ) . Lean calf girth was lower by 4.2 % for the right leg ( p = 0.040 ) but by only 2.9 % for the left leg ( p = 0.141 ) . No intrinsic risk factor was associated with EMTP in women . EMTP was the major cause for non-completion of the run component of the ADFA fitness test in both men and women . Conclusions : Greater internal and external hip range of motion and lower lean calf girth were associated with EMTP in male military cadets . Women had high rates of injury , although no intrinsic factor was identified . Reasons for this sex difference need to be identified Objective : To examine whether dynamic parameters of foot pronation are risk factors for the development of stress fractures of the femur and tibia . Design : Observational prospect i ve study . Setting : Infantry basic training course . Participants : 473 recruits evaluated for stress fractures of the femur and tibia every 2 weeks during 14 weeks of infantry basic training . The final analysis included 405 recruits . Assessment of Risk Factors : Two weeks before commencement of training , the recruits were evaluated during treadmill walking for their subtalar joint kinematics . Five independent variables were measured bilaterally : maximal pronation angle during the stance , pronation range of motion , time from heel strike to maximum pronation , pronation mean angular velocity , and time to maximum pronation as a percent of the total stance time . Main Outcome Measurements : Stress fractures of the femur and tibia . These were considered positive only when proven by imaging . Results : Ten percent of the participants were diagnosed with stress fractures of the femur and tibia . Recruits with longer duration of foot pronation had reduced odds ratio to develop this injury . Conclusions and Clinical Relevance : Longer duration of foot pronation may have a protective effect from stress fractures of the femur and tibia . This finding may promote the underst and ing of stress fracture pathomechanism , assist in the identification of subjects with increased risk who need augmented monitoring throughout training , and assist in future planning of impact reducing aids Excessive foot pronation has been considered to be related to anterior knee pain . We undertook a prospect i ve study to test the hypothesis that exertional anterior knee pain is related to the static and dynamic parameters of foot pronation . Two weeks before beginning basic training lasting for 14 weeks , 473 infantry recruits were enrolled into the study and underwent two-dimensional measurement of their subtalar joint displacement angle during walking on a treadmill . Of the 405 soldiers who finished the training 61 ( 15 % ) developed exertional anterior knee pain . No consistent association was found between the incidence of anterior knee pain and any of the parameters of foot pronation . While a statistically significant association was found between anterior knee pain and pronation velocity ( left foot , p = 0.05 ; right foot , p = 0.007 ) , the relationship was contradictory for the right and left foot . Our study does not support the hypothesis that anterior knee pain is related to excessive foot pronation The purpose of this study was to determine prospect ively gait related risk factors for  exercise-related lower leg pain ( ERLLP ) in 400 physical education students . Static lower leg alignment was determined , and 3D gait kinematics combined with plantar pressure profiles were collected . After this evaluation , all sports injuries were registered by the same sports physician during the duration of the study . Forty six subjects developed  ERLLP and 29 of them developed bilateral symptoms thus giving 75 symptomatic lower legs . Bilateral lower legs of 167 subjects who developed no injuries in the lower extremities served as controls . Cox regression analysis revealed that subjects who developed ERLLP had an altered running pattern before the injury compared to the controls and included ( 1 ) a significantly more central heel-strike , ( 2 ) a significantly increased pronation , accompanied with more pressure underneath the medial side of the foot , and ( 3 ) a significantly more lateral roll-off . These findings suggest that altered biomechanics play a role in the genesis of ERLLP and thus should be considered in prevention and rehabilitation Background Foot orthoses have been demonstrated to be effective in the management of a range of conditions , but there is debate as to the benefits of customised foot orthoses over less expensive , prefabricated devices . Methods In a r and omised , cross-over trial , 15 flat-footed participants aged between 18 and 45 years were provided with semi-rigid , customised orthoses and semi-rigid , contoured , prefabricated orthoses .  Pressures and forces were measured using an in-shoe system with subjects wearing shoes alone , wearing customised orthoses , and again when wearing contoured prefabricated orthoses . Two weeks acclimatisation was included between cross-over of therapy . Repeated measures ANOVA models with post-hoc , pair-wise comparisons were used to test for differences . Results When compared to wearing shoes alone , wearing either the customised orthoses or the prefabricated orthoses was associated with increases in force and force time integrals in the midfoot region . Peak and maximum mean pressure and pressure-time , and force-time integrals were reduced in both the medial and lateral forefoot . There were , however , no significant differences between the customised orthoses and the prefabricated orthoses at any site . Conclusion There was a similar change in loading with both the semi-rigid customised and the semi-rigid prefabricated orthoses when compared to the shoe alone condition . However , while customised devices offered minor differences over prefabricated orthoses in some variables , these were not statistically significant . The results suggest that there may be only minor differences in the effects on plantar pressures between the customised and the less expensive prefabricated orthoses tested in this study , however further research is warranted PURPOSE The purpose of this study was to examine the relationships between isotonic ankle plantar flexor endurance ( PFE ) , foot pronation as measured by navicular drop , and exercise-related leg pain ( ERLP ) . BACKGROUND Exercise-related leg pain is a common occurrence in competitive and recreational runners . The identification of factors contributing to the development of ERLP may help guide methods for the prevention and management of overuse injuries . METHODS Seventy-seven ( 44 males , 33 females ) competitive runners from five collegiate cross-country ( XC ) teams consented to participate in the study . Isotonic ankle PFE and foot pronation were measured using the st and ing heel-rise and navicular drop ( ND ) tests , respectively . Demographic information , anthropometric measurements , and ERLP history were also recorded . Subjects were then prospect ively tracked for occurrence of ERLP during the 2009 intercollegiate cross-country season . Multivariate logistic regression analysis was used to examine the relationships between isotonic ankle joint PFE and ND and the occurrence of ERLP . RESULTS While no significant differences were identified for isotonic ankle PFE between groups of collegiate XC runners with and without ERLP , runners with a ND > 10 mm were almost 7 times ( OR=6.6 , 95 % CI=1.2 - 38.0 ) more likely to incur medial ERLP than runners with ND < 10 mm . Runners with a history of ERLP in the month previous to the start of the XC season were 12 times ( OR=12.3 , 95 % CI=3.1 -  
    Output:
    
Conclusion This systematic review identified very limited evidence that dynamic foot function during walking and running is a risk factor for patellofemoral pain , Achilles tendinopathy , and non-specific lower limb overuse injuries .
It is unclear whether these risk factors can be identified clinical ly ( without sophisticated equipment ) , or modified to prevent or manage these injuries .