***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: The aim of this study was to assess the influence of  footwear with increased ankle support  on  ankle kinematics and on impact loads  during l and ing from a vertical jump using high-speed cinematography , dynamometry and accelerometry in a series of tests in which a rebound action was simulated . To analyse the effect of this increased support on motor performance , two performance tests were design ed : a vertical jump test and an obstacle course running test . Two prototype shoes with identical soles but different uppers were used . The first was design ed to provide greater ankle support , with such features as a high top , heel counters and a rearfoot lacing system . The second prototype was a less supporting shoe , with low top and no heel counter or any other feature for support . In the shock attenuation test , the use of high-support shoes result ed in higher forefoot impact forces and higher shock transmission to the head , but showed lower shock transmission to the tibia . The use of high support shoes result ed in lower ranges of eversion and higher ranges of inversion of the ankle on l and ing . In the motor performance tests , the high-support shoes reduced the height jumped and increased the time to complete the running course relative to the low-support shoes . We conclude that increased ankle support reduces ankle eversion range but increases shock transmission , and reduces both jumping and running performance Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more The purpose s of this investigation were to determine if increasing the bending stiffness of  sprint shoes increases sprinting performance and to determine whether simple anthropometric factors can be used to predict shoe bending stiffness for optimal performance . Thirty-four athletes were tested using four different shoe conditions -- a st and ard condition consisting of their currently used footwear and three conditions where the bending stiffness was increased systematic ally . The sprinters performed maximal effort 40 m sprints and their sprint times were recorded from 20 to 40 m. On average , increasing the shoe bending stiffness increased sprint performance . The stiffness each athlete required for his or her maximal performance was subject specific but was not related to subject mass , height , shoe size or skill level . It is speculated that individual differences in the force-length and force-velocity relationships of the calf muscles may influence the appropriate shoe stiffness for each athlete to obtain their maximal performance The purpose s of this study were ( a ) to determine group and individual differences in oxygen consumption during  heel-toe running and ( b ) to quantify the differences in EMG activity for selected muscle groups of the lower extremities when running in shoes with different mechanical heel characteristics . Twenty male runners performed heel-toe running using two shoe conditions , one with a mainly elastic and a visco-elastic heel .  Oxygen consumption was quantified during steady state runs of 6 min duration , running slightly above the aerobic threshold providing four pairs of oxygen consumption results for comparison . Muscle activity was quantified using bipolar  surface EMG  measurements from the tibialis anterior , medial gastrocnemius , vastus medialis and the hamstrings muscle groups . EMG data were sample d for 5 s every minute for the 6 min providing 30 trials . EMG data were compared for the different conditions using an ANOVA ( alpha=0.05 ) . The findings of this study showed that changes in the heel material characteristics of running shoes were associated with ( a ) subject specific changes in oxygen consumption and ( b ) subject and muscle specific changes in the intensities of muscle activation before heel strike in the lower extremities . It is suggested that further study of these phenomena will help underst and many aspects of human locomotion , including work , performance , fatigue and possible injuries The purpose of this investigation was to examine the combined effects of resistance and sprint/plyometric training with or without the Meridian Elyte athletic shoe on  muscular performance in women . Fourteen resistance-trained women were r and omly assigned to one of 2 training groups : ( a ) an athletic shoe ( N = 6 ) ( AS ) group or ( b ) the Meridian Elyte ( N = 8) ( MS ) group . Training was performed for 10 weeks and consisted of resistance training for 2 days per week and 2 days per week of sprint/plyometric training . Linear periodized resistance training consisted of 5 exercises per workout ( 4 lower body , 1 upper body ) for 3 sets of 3–12 repetition maximum ( RM ) . Sprint/plyometric training consisted of 5–7 exercises per workout ( 4–5 plyometric exercises , 40-yd and 60-yd sprints ) for 3–6 sets with gradually increasing volume ( 8 weeks ) followed by a 2-week taper phase . Assessment s for 1RM squat and bench press , vertical jump , broad jump , sprint speed , and body composition were performed before and following the 10-week training period . Significant increases were observed in both AS and MS groups in 1RM squat ( 12.0 vs. 14.6 kg ) , bench press ( 6.8 vs. 7.4 kg ) , vertical jump height ( 3.3 vs. 2.3 cm ) , and broad jump ( 17.8 vs. 15.2 cm ) . Similar decreases in peak 20- , 40- , and 60-m sprint times were observed in both groups ( 20 m : 0.14 vs. 0.11 seconds ; 40 m : 0.29 vs. 0.34 seconds ; 60 m : 0.45 vs. 0.46 seconds in AS and MS groups , respectively ) . However , when sprint endurance ( the difference between the fastest and slowest sprint trials ) was analyzed , there was a significantly greater improvement at 60 m in the MS group . These results indicated that similar improvements in peak sprint speed and jumping ability were observed following 10 weeks of training with either shoe . However , high-intensity sprint endurance at 60 m increased to a greater extent during training with the Meridian Elyte athletic shoe PURPOSE The purpose of this study was to assess research aim ed at measuring performance enhancements that affect success of individual elite athletes in competitive events . ANALYSIS Simulations show that the smallest worthwhile enhancement of performance for an athlete in an international event is 0.7 - 0.4 of the typical within-athlete r and om variation in performance between events . Using change in performance in events as the outcome measure in a crossover study , research ers could delimit such enhancements with a sample of 16 - 65 athletes , or with 65 - 260 in a fully controlled study . Sample size for a study using a valid laboratory or field test is proportional to the square of the within-athlete variation in performance in the test relative to the event ; estimates of these variations are therefore crucial and should be determined by repeated- measures analysis of data from reliability studies for the test and event . Enhancements in test and event may differ when factors that affect performance differ between test and event ; overall effects of these factors can be determined with a validity study that combines reliability data for test and event . A test should be used only if it is valid , more reliable than the event , allows estimation of performance enhancement in the event , and if the subjects replicate their usual training and dietary practice s for the study ; otherwise the event itself provides the only dependable estimate of performance enhancement . Publication of enhancement as a percent change with confidence limits along with an analysis for individual differences will make the study more applicable to athletes . Outcomes can be generalized only to athletes with abilities and practice s represented in the study . CONCLUSION estimates of enhancement of performance in laboratory or field tests in most previous studies may not apply to elite athletes in competitive events Lower energy cost of running ( Cr ) has been reported when wearing minimal ( MS ) vs traditional shoes ( TS ) on level terrain , but the effect of slope on this difference is unknown . The aim of this study was to compare Cr , physiological , and kinematic variables from running in MS and TS on different slope conditions . Fourteen men ( 23.4 ± 4.4 years ; 177.5 ± 5.2 cm ; 69.5 ± 5.3 kg ) ran 14 5-min trials in a r and omized sequence at 10 km/h on a treadmill . Subjects ran once wearing MS and once wearing TS on seven slopes , from -8 % to + 8 % . We found that Cr increased with slope gradient ( P < 0.01 ) and was on average 1.3 % lower in MS than TS ( P < 0.01 ) . However , slope did not influence the Cr difference between MS and TS . In MS , contact times were lower ( P < 0.01 ) , flight times ( P = 0.01 ) and step frequencies ( P = 0.02 ) were greater at most slope gradients , and plantar-foot angles - and often ankle plantar-flexion ( P = 0.01 ) - were greater ( P < 0.01 ) . The 1.3 % difference between footwear identified here most likely stemmed from the difference in shoe mass considering that the Cr difference was independent of slope gradient and that the between-footwear kinematic alterations with slope provided limited explanations The purpose of this study was to evaluate the effects of a 4-week familiarization to simulated barefoot running ( SBR ) on running economy ( RE ) when compared with shod running .  Fifteen trained male runners ( age : 24 ± 4 years ; stature : 177.2 ± 6.21 cm ; mass : 67.99 ± 7.36 kg and VO2max 70.2 ± 5.2 mL/kg/min ) were recruited . Subjects completed two RE tests , 24 h apart , in a r and om order , in both the SBR and shod condition ( pretest ) at 11 km/h and 13 km/h . Oxygen uptake , heart rate , stride frequency , and foot strike patterns were measured in both conditions . Subjects then completed a 4-week familiarization period of SBR , before repeating the two RE tests ( post-test ) . At pretest , there was no significant difference in RE between SBR and shod running ( P = 0.463 ) , but following the 4-week familiarization period , RE significantly improved by 6.9 % in the SBR condition compared with shod running ( 46.4 ± 0.9 vs 43.2 ± 1.2 mL/kg/min ; P = 0.011 ) . A significant improvement in RE was observed in the SBR condition ( 8.09 % ) between the pretest and post-test ( 47.0 ± 1.2 vs 43.2 ± 1.2 mL/kg/min ; P = 0.002 ) . RE improved in the SBR condition as a result of familiarization , and became significantly lower in SBR compared with shod running 
    Output:
    
Footwear with a combined shoe mass less than 440 g per pair had no detrimental effect on running economy .
Conclusions Certain models of footwear and footwear characteristics can improve running economy .