***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: Abstract The purpose of this study was to determine whether there are differences in the perceived comfort , plantar pressure , and rearfoot motion between laced running shoes and elastic-covered running shoes .  Fifteen male amateur runners participated in the study . Each participant was assigned laced running shoes and elastic-covered running shoes for use during the study . The perceived comfort , plantar loading , and rearfoot motion control of each type of shoes during running were recorded . When the laced running shoes and elastic-covered running shoes were compared , the elastic-covered running shoes were given a lower perceived comfort rating in terms of shoe length , width , heel cup fitting , and forefoot cushioning . The elastic-covered running shoes also recorded higher peak plantar pressure in the lateral side of the forefoot , as well as larger maximum rearfoot pronation . Overall , shoelaces can help runners obtain better foot – shoe fit . They increase the perceived comfort , and decrease the maximum pronation and plantar pressure . Moreover , shoelaces may help prevent injury in running by allowing better control of the aforementioned factors Background While minimalist running shoes may have an influence on running biomechanics and on the incidence of overuse injuries , the term " minimalist " is currently used without st and ardisation . The objectives of this study were to reach a consensus on a st and ard definition of minimalist running shoes , and to develop and vali date a rating scale that could be used to determine the degree of minimalism of running shoes , the Minimalist Index ( MI ) . Methods For this modified Delphi study , 42 experts from 11 countries completed four electronic question naires on an optimal definition of minimalist shoes and on elements to include within the MI . Once MI was developed following consensus , 85 participants subjectively ranked r and omly assigned footwear models from the most to the least minimalist and rated their degree of minimalism using visual analog scales ( VAS ) , before evaluating the same footwear models using MI . A sub sample of thirty participants reassessed the same shoes on another occasion . Construct validity and inter- and intra-rater reliability ( intraclass correlation coefficients [ ICC ] ; Gwet 's AC1 ) of MI were evaluated . Results The following definition of minimalist shoes was agreed upon by 95 % of participants : " Footwear providing minimal interference with the natural movement of the foot due to its high flexibility , low heel to toe drop , weight and stack height , and the absence of motion control and stability devices " . Characteristics to be included in MI were weight , flexibility , heel to toe drop , stack height and motion control/stability devices , each subscale carrying equal weighing ( 20 % ) on final score . Total MI score was highly correlated with VAS ( r = 0.91 ) . A significant rank effect ( p < 0.001 ) confirmed the MI 's discriminative validity . Excellent intra- and inter-rater reliability was found for total MI score ( ICC = 0.84 - 0.99 ) and for weight , stack height , heel to toe drop and flexibility subscales ( AC1 = 0.82 - 0.99 ) , while good inter-rater reliability was found for technologies ( AC1 = 0.73 ) . Conclusion This st and ardised definition of minimalist shoes developed by an international panel of experts will improve future research on minimalist shoes and clinical recommendations . MI 's adequate validity and reliability will allow distinguishing running shoes based on their degree of minimalism , and may help to decrease injuries related to footwear transition OBJECTIVES This study investigated if gradually introducing runners to minimalist shoes during training improved running economy and time-trial performance compared to training in conventional shoes . Changes in stride rate , stride length , footfall pattern and ankle plantar-flexor strength were also investigated . DESIGN R and omised parallel intervention trial . METHODS 61 trained runners gradually increased the amount of running performed in either minimalist ( n=31 ) or conventional ( n=30 ) shoes during a six-week st and ardised training program . 5-km time-trial performance , running economy , ankle plantar-flexor strength , footfall pattern , stride rate and length were assessed in the allocated shoes at baseline and after training . Footfall pattern was determined from the time differential between rearfoot and forefoot ( TDR-F ) pressure sensors . RESULTS The minimalist shoe group improved time-trial performance ( effect size ( ES ) : 0.24 ; 95 % confidence interval ( CI ) : 0.01 , 0.48 ; p=0.046 ) and running economy ( ES 0.48 ; 95%CI : 0.22 , 0.74 ; p<0.001 ) more than the conventional shoe group . There were no minimalist shoe training effects on ankle plantar-flexor concentric ( ES : 0.11 ; 95%CI : -0.18 , 0.41 ; p=0.45 ) , isometric ( ES : 0.23 ; 95%CI : -0.17 , 0.64 ; p=0.25 ) , or eccentric strength ( ES : 0.24 ; 95%CI : -0.17 , 0.65 ; p=0.24 ) . Minimalist shoes caused large reductions in TDR-F ( ES : 1.03 ; 95%CI : 0.65 , 1.40 ; p<0.001 ) but only two runners changed to a forefoot footfall .  Minimalist shoes had no effect on stride rate ( ES : 0.04 ; 95%CI : -0.08 , 0.16 ; p=0.53 ) or length ( ES : 0.06 ; 95%CI : -0.06 , 0.18 ; p=0.35 ) . CONCLUSIONS Gradually introducing minimalist shoes over a six-week training block is an effective method for improving running economy and performance in trained runners BACKGROUND The use of cushioned or shock-absorbing insoles has been suggested as a mechanism to reduce the impact forces associated with running , thereby protecting against overuse injuries . The purpose of this study was to determine whether the use of cushioned insoles reduced impact forces during running in healthy subjects . METHODS Sixteen recreational runners ( 9 females and 7 males ) ran at a self-selected pace for five trials with and without the use of cushioned insoles . During each trial , ground reaction forces , tibial accelerations , lower-extremity kinematics , and subject-perceived comfort were recorded . All variables were tested with the level of statistical significance set at alpha = .05 . RESULTS The use of cushioned insoles result ed in significant reductions in mean vertical ground reaction force peak impact ( 6.8 % ) and ground reaction force loading rate ( 8.3 % ) , as well as peak tibial acceleration ( 15.8 % ) . Spectral analysis of the tibial acceleration data in the frequency range associated with impact accelerations ( 12 - 25 Hz ) revealed no change in the predominant frequency or the power of the predominant frequency . The knee flexion angle at initial contact and perceived comfort were similar for the two conditions . CONCLUSIONS This study demonstrates the effectiveness of one type of cushioned insole in reducing peak impact force and tibial acceleration at initial foot-ground contact during running . The impact reduction observed was independent of knee kinematic adjustments or changes in perceived comfort . Further study is required to determine whether the reduction in loading that accompanied the use of the cushioned insoles can affect the incidence of running-related injuries CONTEXT Achilles tendons ( ATs ) adapt to increased loading generated by long-term adoption of a minimalist shoe running style . There may be difference in the chronology and extent of adaptation between the sexes . OBJECTIVE To learn the chronology of AT adaptations in female and male runners who transitioned to a minimalist running style through a planned , progressive 12-wk transition program . DESIGN Prospect i ve cohort study of well-trained , traditionally shod runners who transitioned to minimalist shoe running .  SETTING Repeated laboratory assessment at baseline and 3 , 12 , and 24 wk after initiating transition program . PARTICIPANTS Fifteen women and 7 men ( of 29 enrolled ) completed the study . MAIN OUTCOME MEASURES The authors used diagnostic ultrasound and isokinetic dynamometry to generate a force elongation curve and its derivatives at each time point . RESULTS Greater adaptations were observed in men than in women , with men generating more force and having greater increases in CSA , stiffness , and Young 's modulus and less elongation after 12 wk of training . CONCLUSION Men demonstrated changes in AT properties that were consistent with increased loading of the triceps surae during exercise . The women demonstrated far smaller changes . Further investigation is warranted to underst and when adaptations may occur in women and the implication s of altered AT mechanical properties for performance and injury risk Background In this double-blind r and omised controlled trial , we tested if leisure-time runners using shoes with less compliant midsoles have a higher  running-related injury ( RRI ) risk . Method We provided 247 runners with st and ard running shoes having either a soft study shoes ( soft-SS ) or a hard study shoes ( hard-SS ) midsole  and followed them prospect ively for 5 months regarding RRI . All information about sports practice and injuries was uploaded on a dedicated internet platform and checked for consistency and completeness . RRI was defined as any first-time pain sustained during or as a result of running practice and impeding normal running activity for at least 1 day . Cox proportional hazards regressions were used to identify RRI risk factors . Result The type of study shoes used for running was not associated with RRIs ( HR=0.92 ; 95 % CI 0.57 to 1.48 ) . The hard-SS had a 15 % greater overall stiffness in the heel region . The two study groups were similar regarding personal and sports participation characteristics , except for years of running experience , which was higher ( p<0.05 ) in the hard-SS group . Global RRI incidence was 12.1 RRI/1000 h of running . No between-group differences were found regarding injury location , type , severity or category . Nevertheless , the adjusted regression model revealed positive associations with RRI risk for body mass index ( HR=1.126 ; 95 % CI 1.033 to 1.227 ) , previous injury ( HR=1.735 ; 95 % CI 1.037 to 2.902 ) and mean session intensity ( HR=1.396 ; 95 % CI 1.040 to 1.874 ) . Protective factors were previous regular running activity ( HR=0.422 ; 95 % CI 0.228 to 0.779 ) and weekly volume of other sports activities ( HR=0.702 ; 95 % CI 0.561 to 0.879 ) . Conclusions Midsole hardness of modern cushioned running shoes does not seem to influence RRI risk Background : Minimalist shoes have been popularized as a safe alternative to conventional running shoes . However , a paucity of research is available investigating the longer-term safety of minimalist shoes . Purpose : To compare running-related pain and injury between  minimalist and conventional shoes in trained runners and to investigate interactions between shoe type , body mass , and weekly training distance . Study Design : R and omized clinical trial ; Level of evidence , 2 . Methods : Sixty-one trained , habitual rearfoot footfall runners ( mean ± SD : body mass , 74.6 ± 9.3 kg ; weekly training distance , 25 ± 14 km ) were r and omly allocated to either minimalist or conventional shoes . Runners gradually increased the time spent running in their allocated shoes over 26 weeks . Running-related pain intensity was measured weekly by use of 100-mm visual analog scales . Time to first running-related injury was also assessed . Results : Interactions were found between shoe type and weekly training distance for weekly running-related pain ; greater pain was experienced with minimalist shoes ( P < .05 ) , and clinical ly meaningful increases ( > 10 mm ) were noted when the weekly training distance was more than 35 km/wk . Eleven of 30 runners  sustained an injury in conventional shoes compared with 16 of 31 runners in minimalist shoes ( hazard ratio , 1.64 ; 95 % confidence interval , 0.63 - 4.27 ; P = .31 ) . A shoe × body mass interaction was found for time to first running-related injury ( P = .01 ) . For runners using minimalist shoes , relative to runners using conventional shoes , the risk of sustaining an injury became more likely with increasing body mass above 71.4 kg , and the risk was moderately increased ( hazard ratio , 2.00 ; 95 % confidence interval , 1.10 - 3.66 ; P = .02 ) for runners using minimalist shoes who had a body mass of 85.7 kg . Conclusions : Runners should limit weekly training distance in minimalist shoes to avoid running-related pain . Heavier runners are at greater risk of injury when running in minimalist shoes . Registration : Australian New Zeal and Clinical Trials Registry ( ACTRN12613000642785 ) PURPOSE The purpose of this study was to quantify effects of shoe sole modification on skeletal kinematics of the calcaneus and tibia during the stance phase of running . METHODS Intracortical bone pins with reflective marker triads were inserted under st and ard local anesthetic into the calcaneus and tibia of five healthy male subjects . The three-dimensional tibiocalcaneal rotations were determined using a joint coordinate system approach . Three shoe sole modifications were tested with different sole geometry : a lateral heel flare of 25 degrees ( flared ) , no flare 0 degrees ( straight ) , and a rounded sole . RESULTS The results showed that these shoe sole modifications did not change tibiocalcaneal rotations substantially . The shoe sole effects at the 
    Output:
    
Some running shoe constructions positively affect athletic performance-related and injury-related variables : 1 ) increasing the stiffness of running shoes at the optimal range can benefit performance-related variables ; 2 ) softer midsoles can reduce impact forces and loading rates ; 3 ) thicker midsoles can provide better cushioning effects and attenuate shock during impacts but may also decrease plantar sensations of a foot ; 4 ) minimalist shoes can improve running economy and increase the cross-sectional area and stiffness of Achilles tendon but it would increase the metatarsophalangeal and ankle joint loading compared to the conventional shoes .