***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 OBJECTIVE To compare differences in kinematic and kinetic parameters of knee , hip and ankle joints between male and female college volleyball players . DESIGN Cross-sectional study . BACKGROUND L and ing injuries , which usually involve anterior cruciate ligament injuries , are common in volleyball with a higher incidence in females . L and ing preferences of both male and female players may provide additional background about the mechanisms contributing to the anterior cruciate ligament injuries . METHODS Eight female and eight male college volleyball players performed spike and block l and ings from 40 and 60 cm height platforms .  Lower extremity joint kinetics and kinematics , and leg muscle strengths were recorded . RESULTS Females demonstrated significantly lower knee and hip flexion angles compared to their male counterparts in knee flexion at 40 cm spike and hip flexion at 40 cm block l and ings . Group comparison also revealed that male players ' peak knee extensor moment at 60 cm block l and ing was significantly different than female players . Additionally , female players applied significantly higher normalized ground reaction forces and males knee flexion angles and thigh muscle strength results positive and highly correlated but relation could not found in females . It is likely that females may not use their thigh muscles as effective as males in l and ing . CONCLUSION Female volleyball players initiate different lower extremity mechanics during l and ings than that of males . RELEVANCE Identifying the l and ing strategy differences between female and male college volleyball players may provide detailed perspective about the load distribution in lower extremity joints for determining major factors affecting the increased incidence of anterior cruciate ligament injuries in females Objective : To evaluate the effectiveness of a preseason physical training programme that taught l and ing and falling skills in improving l and ing skills technique and preventing injury in junior elite Australian football players . Methods : 723 male players who participated in an under 18 elite competition were studied prospect ively in a non-r and omised controlled trial over two consecutive football seasons . There were 114 players in the intervention group and 609 control players . The eight session intervention programme taught players six l and ing , falling , and recovery skills , which were considered fundamental for safe l and ing in Australian football . L and ing skills taught in these sessions were rated for competence by independent and blinded assessors at baseline and mid-season . Results : Evaluation of l and ing skills found no significant differences between the groups at baseline . Evaluation after the intervention revealed overall improvement in l and ing skills , but significantly greater improvement in the intervention group ( z = −7.92 , p = 0.001 ) . Players in the intervention group were significantly less likely ( relative rate 0.72 , 95 % confidence interval 0.52 to 0.98 ) to sustain an injury during the season than the control group . In particular , the time to sustaining a l and ing injury was significantly less for the intervention group ( relative rate 0.40 , 95 % confidence interval 0.17 to 0.92 ) compared with the control group . Conclusions : L and ing and falling ability can be taught to junior elite Australian football players . Players in the intervention group were protected against injury , particularly injuries related to l and ing and falls This study aim ed to investigate the influence of prophylactic ankle taping on two balance tests ( static and dynamic balance ) and one jump test , in the push off and the l and ing phase . Fifteen active young subjects ( age : 21.0 ± 4.4 years ) without previous ankle injuries volunteered for the study . Each participant performed three tests in two different situations : with taping and without taping . The tests were a counter movement jump , static balance , and a dynamic posturography test . The tests and conditions were r and omly performed . The path of the center of pressures was measured in the balance tests , and the vertical ground reaction forces were recorded during the push-off and l and ing phases of the counter movement jump . Ankle taping had no influence on balance performance or in the push off phase of the jump . However , the second peak vertical force value during the l and ing phase of the jump was 12 % greater with ankle taping ( 0.66 BW , 95 % CI -0.64 to 1.96 ) . The use of prophylactic ankle taping had no influence on the balance or jump performance of healthy young subjects . In contrast , the taped ankle increased the second peak vertical force value , which could be related to a greater risk of injury produced by the accumulation of repeated impacts in sports where jumps are frequently performed . Key pointsAnkle taping has no influence on balance performance . Ankle taping does not impair performance during the push-off phase of the jump . Ankle taping could increase the risk of injury during l and ings by increasing peak forces Objective —To examine the effects of instructions related to joint kinematics , auditory stimuli , and imagery on lowering the vertical ground reaction forces associated with l and ing from a jump . Study Design —R and omised controlled trial . Setting —A laboratory in an educational institution . Subjects — Eighty asymptomatic subjects ( 27 men ) with a mean age of 24 years . Intervention — Subjects were r and omly assigned to the following groups : ( 1 ) instruction ( limb position instructions ) ; ( 2 ) auditory cue ( listen to impact sounds ) ; ( 3 ) imagery ( metaphorical ) ; ( 4 ) control . Subjects were required to jump from a box 300 mm in height and l and on a force plate . Measures of the ground reaction force were recorded before and after the intervention . Main Outcome Measure — The peak vertical ground reaction force recorded at footstrike . Results —The peak vertical ground reaction forces in the technical instruction and auditory groups were significantly less than those of the control group . There was no significant difference between the auditory and technical instruction groups . There was no significant difference between the imagery and control groups . Conclusions —When an aim of a rehabilitation programme is to minimise forces on the lower limb during l and ing type activities , the findings support the use of instructions related to kinematics as well as instructions that draw the patient 's attention to the sound at impact UNLABELLED Anterior cruciate ligament ( ACL ) injuries have been reported to occur with the ankle in a dorsiflexed position at initial contact . Few studies have attempted to quantify the biomechanical parameters related with such l and ing patterns during athletic tasks . OBJECTIVES The purpose of this study was to evaluate the effects that two l and ing techniques have in lower extremity biomechanics while performing two tasks . DESIGN Single-group repeated measures design . METHODS Twenty female soccer athletes from a Division I institution performed two l and ing techniques ( forefoot and rearfoot ) during two unanticipated tasks ( sidestep cutting and pivot ) . Repeated measures analyses of variance were conducted to assess differences in the kinematic and kinetic parameters between l and ing techniques for each task . RESULTS The forefoot l and ing technique had significantly higher internal knee adductor moment than the rearfoot for both the pivot and sidestep cutting task ( p<0.001 and p=0.003 , respectively ) . For the sidestep cutting task , participants had increased knee valgus angle with the rearfoot , whereas for the pivot they had increased knee valgus with the forefoot l and ing technique ( p<0.05 ) . CONCLUSIONS The results of this study highlighted that there are inherent differences in biomechanical outcomes between foot-l and ing techniques . The forefoot l and ing technique increasingly affects knee adduction moment loading , which can potentially place a higher strain on the ACL . Essentially , the dem and s of the l and ing technique on lower extremity biomechanics ( e.g. , hip and knee ) are task dependent Abstract The aim of this study was to develop insight into the whole-body and multi-joint kinematic control strategy variability associated with the execution of fundamental backward rotating dismounts from beam . Two-dimensional joint centre coordinate data were obtained for ten backward piked and backward tucked somersault dismount skills performed by four female gymnasts ( N = 80 trials ) . Gymnast-specific and group variability in whole-body and multi-joint discrete kinematic measures were compared for the aerial and impact phase of backward piked and backward tucked skills . The backward tucked skill was executed using a more variable knee joint angular velocity at take-off ( mean difference in st and ard deviation ± SD : −2.6 ± 1.0 rad · s−1 ; P < 0.01 ) than the backward piked skill . The variability in the whole-body and multi-joint kinematic responses produced between the impact phases of each skill was gymnast-specific . The greater variability in the localized knee joint action at take-off was considered indicative of the diverse shape element dem and s and key performance outcomes of the two skills . Self-selected modulations to the multi-joint kinematic strategy used in the impact phase suggested customization of the joint loading adjustments in executing the fundamental dismount skills 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 force , as well as the time to each of the 2 peak forces , were determined for each trial and used as dependent variables . RESULTS The time to reach peak forces were significantly less under the ankle brace and tape conditions in comparison to the control ( no-stabilizer ) condition . CONCLUSIONS It appears that ankle taping and bracing decrease the time to reach peak impact forces . These alterations indicate that during dynamic activity the musculoskeletal structures of the body may be subjected to loads within shorter time periods . Whether these effects are detrimental over time remains speculative at this point and requires further research OBJECTIVE To determine whether gender differences exist in lower extremity joint motions and energy absorption l and ing strategies between age and skill matched recreational athletes . DESIGN Mixed factor , repeated measures design . BACKGROUND Compared to males , females execute high dem and activities in a more erect posture potentially predisposing the anterior cruciate ligament to greater loads and injury . The preferred energy absorption strategy may provide insight for this performance difference . METHODS Inverse dynamic solutions estimated lower extremity joint kinematics , kinetics and energetic profiles for twelve males and nine females performing a 60 cm drop l and ing .  RESULTS Females demonstrated a more erect l and ing posture and utilized greater hip and ankle joint range of motions and maximum joint angular velocities compared to males . Females also exhibited greater energy absorption and peak powers from the knee extensors and ankle plantar-flexors compared to the males . Examinations of the energy absorption contributions revealed that the knee was the primary shock absorber for both genders , whereas the ankle plantar-flexors muscles was the second largest contributor to energy absorption for the females and the hip extensors muscles for the males . CONCLUSIONS Females may choose to l and in a more erect posture to maximize the energy absorption from the joints most proximal to ground contact . RELEVANCE Females may be at a greater risk to anterior cruciate ligament injury during l and ing due to their energy absorption strategy Wallace , BJ , Kernozek , TW , White , JM , Kline , DE , Wright , GA , Peng , H-T , and Huang , C-F. Quantification of vertical ground reaction forces of popular  bilateral plyometric exercises .  J Strength Cond Res 24(1 ) : 207 - 212 , 2010-The purpose of this study was to quantify the vertical ground reaction forces ( VGRFs ) developed during the performance of popular bilateral plyometric movements . Fourteen power-oriented track and field men of collegiate and national level r and omly performed 3 trials of 9 different bilateral plyometric exercises in a single testing session . Three depth drop ( DD ) and 3 depth jump ( DJ ) conditions from 30 , 60 , and 90 cm heights ( DD30 , DD60 , and DD90 and DJ30 , DJ60 , and DJ90 ) were tested , in addition to vertical jump ( VJ ) , st and ing long jump ( SLJ ) , and 2 consecutive jump ( 2CJ ) conditions . Peak impact VGRFs were normalized to body weight . Additionally , all conditions were compared against the VJ in an intensity index . The SLJ condition result ed in a significantly higher peak VGRF than the 2CJ condition ( p  
    Output:
    
The PvGRF and root DH showed a linear relationship .
The mathematical modeling method with systematic review is helpful to analyze the influence factors during l and ing movement without considering DH