***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: OBJECTIVES To investigate the effect of bracing and taping on selected electromyographic , kinematic , and kinetic variables when l and ing from a jump . METHODS Fifteen netball players performed a jump , so as to l and on their dominant limb on a force plate . Electromyographic activity was recorded from the gastrocnemius , tibialis anterior , and peroneus longus muscles . Subjects were also filmed and measures of rearfoot motion were derived . RESULTS Significantly less electromyographic activity ( p<0.007 ) was observed from the gastrocnemius and peroneus longus muscle groups when subjects were braced . No other significant electromyographical findings were observed . Peak vertical ground reaction force and time to peak for vertical ground reaction force were not affected by bracing and taping , nor were the rearfoot and Achilles tendon angles at foot strike . CONCLUSIONS The effect of bracing and taping on the selected biomechanics variables associated with l and ing was specifically limited to a reduction in muscle action , particularly for the braced condition . Netball players can be confident that the biomechanics of their l and ing patterns will not be altered whether they choose to wear a brace or tape their ankle joints PURPOSE Ankle joint dorsiflexion contributes to energy absorption during l and ing , but wearing ankle stabilizers is known to restrict passive measures of dorsiflexion . This study compared the effects of various ankle stabilizers on ankle joint kinematics during soft and stiff l and ings . METHODS Subjects ( N = 14 ) performed two-legged l and ings off a 0.59-m platform .  Kinematics of the right ankle were calculated from a sagittal plane video recording ( 120 Hz ) . Five soft and five stiff l and ings were performed in five ankle stabilizer conditions ( no stabilizer , taping , Swede-O , AirCast , and Active Ankle ) , a total of 50 trials per subject . Style and stabilizer conditions were r and omized across subjects . Each subject 's five-trial mean value of selected kinematic variables for each l and ing style/stabilizer condition was entered into a two-way repeated MANOVA ( alpha = 0.05 ) . RESULTS Differences between soft and stiff l and ing conditions were similar to those reported in the literature . Compared with the No stabilizer condition , most stabilizer conditions significantly reduced ankle dorsiflexion ROM and angular velocity during l and ing . CONCLUSIONS The results indicate that some ankle stabilizers adversely affect ankle joint kinematics during l and ing BACKGROUND Lower extremity stiffness is thought to be an important factor in musculoskeletal performance . However , too little or too much stiffness is believed to increase the risk of musculoskeletal injury . PURPOSE To provide a current up date of the lower extremity stiffness literature as it pertains to both performance and injury . SUMMARY It appears that increased stiffness is beneficial to performance . As well it appears that there may be an optimal amount of stiffness that allows for injury-free performance . There is some evidence that increased stiffness may be related to bony injuries and decreased stiffness may be associated with soft tissue injuries . Further investigations should evaluate the relationship between stiffness and injury prospect ively . Initial reports suggest that stiffness can be modified in response to the external environment or verbal cues . RELEVANCE A greater underst and ing of the role of stiffness in both performance and injury will provide a stronger foundation for the development of optimal training intervention programs OBJECTIVE : To test the feasibility of creating a valid and reliable checklist with the following features : appropriate for assessing both r and omised and non-r and omised studies ; provision of both an overall score for study quality and a profile of scores not only for the quality of reporting , internal validity ( bias and confounding ) and power , but also for external validity . DESIGN : A pilot version was first developed , based on epidemiological principles , review s , and existing checklists for r and omised studies . Face and content validity were assessed by three experienced review ers and reliability was determined using two raters assessing 10 r and omised and 10 non-r and omised studies . Using different raters , the checklist was revised and tested for internal consistency ( Kuder-Richardson 20 ) , test-retest and inter-rater reliability ( Spearman correlation coefficient and sign rank test ; kappa statistics ) , criterion validity , and respondent burden . MAIN RESULTS : The performance of the checklist improved considerably after revision of a pilot version . The Quality Index had high internal consistency ( KR-20 : 0.89 ) as did the subscales apart from external validity ( KR-20 : 0.54 ) . Test-retest ( r 0.88 ) and inter-rater ( r 0.75 ) reliability of the Quality Index were good . Reliability of the subscales varied from good ( bias ) to poor ( external validity ) . The Quality Index correlated highly with an existing , established instrument for assessing r and omised studies ( r 0.90 ) . There was little difference between its performance with non-r and omised and with r and omised studies . Raters took about 20 minutes to assess each paper ( range 10 to 45 minutes ) . CONCLUSIONS : This study has shown that it is feasible to develop a checklist that can be used to assess the method ological quality not only of r and omised controlled trials but also non-r and omised studies . It has also shown that it is possible to produce a checklist that provides a profile of the paper , alerting review ers to its particular method ological strengths and weaknesses . Further work is required to improve the checklist and the training of raters in the assessment of external validity Objectives : To determine if measurements of static lower limb alignment are related to lower limb injury in recreational runners . Methods : Static lower limb alignment was prospect ively measured in 87 recreational runners . They were observed for the following six months for any running related musculoskeletal injuries of the lower limb . Injuries were defined according to six types : R1 , R2 , and R3 injuries caused a reduction in running mileage for one day , two to seven days , or more than seven days respectively ; S1 , S2 , and S3 injuries caused stoppage of running for one day , two to seven days , or more than seven days respectively . Results : At least one lower limb injury was suffered by 79 % of the runners during the observation period . When the data for all runners were pooled , 95 % confidence intervals calculated for the differences in the measurements of lower limb alignment between the injured and non-injured runners suggested that there were no differences . However , when only runners diagnosed with patellofemoral pain syndrome ( n = 6 ) were compared with non-injured runners , differences were found in right ankle dorsiflexion ( 0.3 to 6.1 ) , right knee genu varum ( −0.9 to −0.3 ) , and left forefoot varus ( −0.5 to −0.4 ) . Conclusions : In recreational runners , there is no evidence that static biomechanical alignment measurements of the lower limbs are related to lower limb injury except patellofemoral pain syndrome . However , the effect of static lower limb alignment may be injury specific CONTEXT Long-term effects of ankle bracing on lower extremity kinematics and kinetics are unknown . Ankle motion restriction may negatively affect the body 's ability to attenuate ground reaction forces ( GRFs ) . OBJECTIVE To evaluate the immediate and long-term effects of ankle bracing on lower extremity kinematics and GRFs during a jump l and ing . DESIGN Experimental mixed model ( 2 [ group ] x 2 [ brace ] x 2 [ time ] ) with repeated measures . SETTING Sports medicine research laboratory . PATIENTS OR OTHER PARTICIPANTS A total of 37 healthy subjects were assigned r and omly to either the intervention ( n = 11 men , 8 women ; age = 19.63 + /- 0.72 years , height = 176.05 + /- 10.58 cm , mass = 71.50 + /- 13.15 kg ) or control group ( n = 11 men , 7 women ; age = 19.94 + /- 1.44 years , height = 179.15 + /- 8.81 cm , mass = 74.10 + /- 10.33 kg ) . INTERVENTION(S ) The intervention group wore braces on both ankles and the control group did not wear braces during all recreational activities for an 8-week period . MAIN OUTCOME MEASURE(S ) Initial ground contact angles , maximum joint angles , time to reach maximum joint angles , and joint range of motion for sagittal-plane knee and ankle motion were measured during a jump-l and ing task . Peak vertical GRF and the time to reach peak vertical GRF were assessed also . RESULTS While participants were wearing the brace , ankle plantar flexion at initial ground contact ( brace = 35 degrees + /- 13 degrees , no brace = 38 degrees + /- 15 degrees , P = .024 ) , maximum dorsiflexion ( brace = 21 degrees + /- 7 degrees , no brace = 22 degrees + /- 6 degrees , P = .04 ) , dorsiflexion range of motion ( brace = 56 degrees + /- 14 degrees , no brace = 59 degrees + /- 16 degrees , P = .001 ) , and knee flexion range of motion ( brace = 79 degrees + /- 16 degrees , no brace = 82 degrees + /- 16 degrees , P = .036 ) decreased , whereas knee flexion at initial ground contact increased ( brace = 12 degrees + /- 9 degrees , no brace = 9 degrees + /- 9 degrees , P = .0001 ) . Wearing the brace for 8 weeks did not affect any of the outcome measures , and the brace caused no changes in vertical GRFs ( P > .05 ) . CONCLUSIONS Although ankle sagittal-plane motion was restricted with the brace , knee flexion upon l and ing increased and peak vertical GRF did not change . The type of lace-up brace used in this study appeared to restrict ankle motion without increasing knee extension or vertical GRFs and without changing kinematics or kinetics over time The purpose of this prospect i ve study was to determine whether an association exists between foot structure and the development of musculoskeletal overuse injuries . The study group was a well-defined cohort of 449 trainees at the Naval Special Warfare Training Center in Coronado , California . Before beginning training , measurements were made of ankle motion , subtalar motion , and the static ( st and ing ) and dynamic ( walking ) characteristics of the foot arch . The subjects were tracked prospect ively for injuries throughout training . We identified risk factors that predispose people to lower extremity overuse injuries . These risk factors include dynamic pes planus , pes cavus , restricted ankle dorsiflexion , and increased hindfoot inversion , all of which are subject to intervention and possible correction OBJECTIVE The aim of the present investigation was to test the stability of 10 different ankle braces under passive and rapidly induced loading conditions in a population suffering from chronic ankle instability in order to provide objective information to choose or recommend an appropriate model for specific needs . In addition , the relationship between passive and rapidly induced testing of the stabilizing effect against inversion was evaluated to identify if passive support characteristics of braces are reflected under rapidly induced conditions . DESIGN An experimental in vivo study with a repeated- measures design was used . BACKGROUND Ankle braces are commonly used for treatment , rehabilitation , and prevention of ankle injuries . A variety of products exists but there is few information available to assist clinicians , physiotherapists and coaches as well as consumers in choosing a brace on a basis of objective information . Furthermore , there is a lack of studies that provide data for both passively and rapidly induced movement of the ankle joint when using different ankle braces . METHODS Twenty-four subjects with chronic ankle instability participated in the project . Passive ankle range of motion measurements were performed in a custom-built fixture and simulated inversion sprains were elicited on a tilting platform . RESULTS The tested braces restrict range of motion significantly compared to the no-brace condition for both the passively and rapidly induced inversion and marked differences between braces were revealed . A close relationship between passive and rapidly induced test results for inversion was found . CONCLUSIONS Passive as well as rapidly induced stability tests provide a basis of objective information to describe the characteristics of different ankle braces . Combined results of passive and rapidly induced inversion as well as correlation between results demonstrate that passive support characteristics of braces are reflected under rapidly induced conditions but the amount of restriction is reduced . Therefore , caution should be taken when recommending braces for applications under dynamic circumstances only on the basis of passive support characteristics . RELEVANCE A basis of information regarding the stability characteristics of different ankle braces under passive and rapidly induced conditions will help the clinician and consumer in choosing the most appropriate brace model for specific use . The results also provide more insights into factors that influence stability characteristics of ankle braces STUDY DESIGN Single-group repeated- measures experimental design . OBJECTIVES The purpose of this study was to evaluate the effects of prophylactic ankle stabilization on vertical ground reaction forces before and after treadmill jogging . BACKGROUND Previous research has demonstrated acute effects of ankle taping and bracing on ankle joint kinematics and vertical ground reaction forces during drop l and ings . Based on the number of investigations demonstrating increased range of motion of the braced or taped ankle following exercise , it may be plausible that the aforementioned l and ing alterations may return to normal following an exercise bout . METHODS AND MEASURES Fourteen healthy recreational participants performed stiff and soft drop l and ings before and after a 20-minute treadmill exercise bout under 3 different ankle stabilizer conditions ( no stabilizer , ankle brace , and ankle tape ) . A forceplate was used to collect ground reaction force data under the dominant foot . The first and second peak impact 
    Output:
    
Overall results suggest that l and ing biomechanics are altered with some brace types but studies disagree as to the particular variables affected .
There is evidence that ankle bracing may alter lower-extremity l and ing biomechanics in a manner which predisposes athletes to injury .