***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: BACKGROUND High peak plantar pressures predispose to foot problems and may exacerbate existing conditions . For podiatric physicians to make educated recommendations to their patients , it is important and necessary to begin to look at different shoes and how they affect peak plantar pressure . METHODS To determine how flip-flops change peak plantar pressure while walking , we compared peak plantar pressures in the same test subjects wearing flip-flops , wearing athletic shoes  , and in bare feet .  Ten women with size 7 feet and a body mass index less than 25 kg/m2 were tested with an in-shoe pressure-measurement system .  These data were collected and analyzed by one-way analysis of variance and computer software . RESULTS Statistically significant results were obtained for nine of the 18 comparisons . In each of these comparisons , flip-flops always demonstrated higher peak plantar pressures than athletic shoes but lower pressures than bare feet . CONCLUSION Although these data demonstrate that flip-flops have a minor protective role as a shock absorber during the gait cycle compared with pressures measured while barefoot , compared with athletic shoes , they increase peak plantar pressures , placing the foot at greater risk for pathologic abnormalities Full body gait analysis was used to determine if differences exist in kinematic , kinetic , and temporal-spatial data with and without shoes in able-bodied children . The greatest difference noted between conditions was an increase in stride length with shoes . Minimal changes were seen in kinematics and kinetics with the addition of shoes . Due to the very tight st and ard deviations of the data , these minimal changes in the magnitude of the curves result ed in statistically significant differences , yet these changes do not appear to be clinical ly significant . It is believed that this study establishes that barefoot gait analysis is sufficient for most clinical studies , and an additional assessment undertaken while wearing shoes is not necessary Walking barefoot or in socks is common for ambulating indoors and has been reported to be associated with increased risk of falls and related injuries in the elderly . This study sought to determine if gait patterns differed between these two conditions for young and older adults . A motion analysis system was used to record and calculate the stride characteristics and motion of the body 's center of mass ( COM ) of 21 young and 20 older adults . For the walking tasks , the participants walked on a smooth floor surface at their preferred speed either barefoot or in socks in a r and om order . The socks were commercially available and commonly used . The results demonstrated that while walking in socks , compared with walking barefoot , older adults adopted a more cautious gait pattern including decreased walking speed and shortened stride length as well as reduced COM minimal velocity during the single limb support phase . Young adults , however , did not demonstrate significant changes . These findings suggest that walking with socks might present a greater balance threat for older adults . Clinical ly , safety pre caution s about walking in socks should be considered to be given to older adults , especially those with balance deficits OBJECTIVE To determine if  women 's dress shoes with heels of just 1.5 in ( 3.8 cm ) in height increases knee joint torques , which are thought to be relevant to the development and /or progression of knee osteoarthritis ( OA ) in both the medial and patellofemoral compartments . DESIGN R and omized controlled trial . SETTING A 3-dimensional motion analysis gait laboratory . PARTICIPANTS Twenty-nine healthy young women ( age , 26.7+/-5.0 y ) and 20 healthy elderly adult women ( age , 75.3+/-6.5 y ) . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Peak external varus knee torque in early and late stance and prolongation of flexor knee torque in early stance . Three-dimensional data on lower-extremity torques and motion were collected during walking while ( 1 ) wearing shoes with 1.5-in high heels and ( 2 ) wearing control shoes without any additional heel . Data were plotted and qualitatively compared ; major peak values and timing were statistically compared between the 2 conditions using paired t tests . RESULTS Peak knee varus torque during late stance was statistically significantly greater with the heeled shoes than with the controls , with increases of 14 % in the young women and 9 % in the elderly women . With the heeled shoes , the early stance phase knee flexor torque was significantly prolonged , by 19 % in the young women and by 14 % in elderly women . Also , the peak flexor torque was 7 % higher with the heeled shoe in the elderly women . CONCLUSIONS Even shoes with moderately high heels ( 1.5 in ) significantly increase knee torques thought to be relevant in the development and /or progression of knee OA . Women , particularly those who already have knee OA , should be advised against wearing these types of shoes In order to further compare shod versus barefoot running , 35 subjects ran two bouts of 4 minutes at 3.33 m x s(-1 ) on a treadmill dynamometer . Parameters were measured on about 60 consecutive steps . Barefoot showed mainly lower contact and flight time ( p < 0.05 ) , lower passive peak ( 1.48 versus 1.70 body weight , p < 0.05 ) , higher braking and pushing impulses ( p < 0.05 ) , and higher pre-activation of triceps surae muscles ( p < 0.05 ) than shod . It was concluded that when performed on a sufficient number of steps , barefoot running leads to a reduction of impact peak in order to reduce the high mechanical stress occurring during repetitive steps . This neural-mechanical adaptation could also enhance the storage and restitution of elastic energy at ankle extensors level 
    Output:
    
Walking barefoot enables increased forefoot spreading under load and habitual barefoot walkers have anatomically wider feet .
Spatial-temporal differences including , reduced step/stride length and increased cadence , are observed when barefoot .
Flatter foot placement , increased knee flexion and a reduced peak vertical ground reaction force at initial contact are also reported .
Habitual barefoot walkers exhibit lower peak plantar pressures and pressure impulses , whereas peak plantar pressures are increased in the habitually shod wearer walking barefoot .
Footwear particularly affects the kinematics and kinetics of gait acutely and chronically .