following stroke , impairments of balance control and gait are major problems for stroke 
 patients , and they restrict activities of daily living and postural control . stroke patients 
 often have impaired ankle function due to muscle weakness and increased spasticity1,2,3 . in addition , ankle instability caused by 
 compression of the deep peroneal , sprained ankles , and excessive joint mobility also cause 
 dysfunctions of balance control and gait4 , 5 . ankle foot orthoses ( afos ) are usually suggested to compensate for impairments of the 
 central nervous system , ankle instability , muscle weakness , and proprioceptive deficits at 
 the ankle joint6,7,8 . afos are prescribed to 
 improve the stability of the ankle joint and gait speed , to reduce energy consumption during 
 gait , and to maintain balance ability , and afos are also used to improve the abnormal gaits 
 of stroke patients and to prevent excessive equinovarus during gait5 , 9,10,11 . afos prevent foot drop and the dragging of the toes during the swing phase by supporting 
 dorsiflexion and limiting plantar flexion , as well as by facilitating heel contact and 
 mediolateral stability12 . studies of 
 postural stability and balance according to features and materials of afos do exist ; 
 however , studies related to the effects of ankle joint angles of afos on gait have not been 
 performed in clinical studies . this study investigated the effects of the ankle angle of an 
 afo on foot pressure during the gait in healthy adults . sixteen healthy males ( age : 26.11.2  years , height : 174.24.1  cm , weight : 71.62.2  kg , foot 
 length : 267.21.8  mm ) participated in this study . they had no orthopedic problems , such as 
 osteoarthritis or fractures , and no neurological problems . all the participants received 
 sufficient explanation of the purposes of the trial , and they gave their written informed 
 consent to participation in this study . the study protocol was approved by the institutional 
 review board for human research and conformed to the ethical principles of the declaration 
 of helsinki . the ankle joint angle was manipulated using afos manufactured with four kinds of 
 inclinations : the neutral position ( 0 ) , 5 of dorsiflexion ( 5 ) , 10 of dorsiflexion ( 10 ) , 
 and 5 of plantarflexion ( 5 ) . the experimental procedure was explained to participants before 
 measurement in order to accurately measure foot plantar pressure , and the subjects practiced 
 walking with an afo for one - minute . after practicing , the f - scan was calibrated according to 
 the manufacturer s protocol for one second . the subjects were asked to walk several times as 
 naturally and directly as possible while looking straight ahead . foot pressure was measured 
 using a matrix - shaped f - scan system ( tekscan , usa ) during gait13 . the f - scan incorporates a grid of 960 force and pressure 
 sensors beneath the entire plantar surface of the foot . the ultrathin film insole containing 
 the sensors was trimmed to each subject s afo size before insertion . the recorded pressures of each pressure sensor were transmitted to a personal computer and 
 were sampled at 60 frames / sec using the teckscan program . foot pressure was analyzed using 
 pressure measurement system after separating the data of the different plantar areas . for 
 foot plantar pressure measurement , the plantar regions were divided into seven distinct 
 regions : the hallux , 2nd5th toes , 1st metatarsal head , 2nd and 3rd metatarsal heads , 4th 
 and 5th metatarsal heads , midfoot , and the heel region . the data of the peak foot pressure was collected for each foot region . once natural walking 
 of the participants was confirmed , the data from the middle 5 seconds of gait were used in 
 the analysis because the participants were blind to the measured time . the mean value of the peak pressure of each 
 region was calculated after measuring the foot pressure using the f - scan research 5.83 
 program . one minute of rest was provided between measurements , and five minutes of rest was 
 provided between the wearing of the orthoses with different ankle angles . one - way 
 repeated measures anova was performed to compare the differences in foot pressure , and 
 tukey s post - hoc test was used to analyze the differences among the ankle angles using spss 
 18.0 . the peak foot pressures of the hallux , 2nd5th toes , 2nd and 3rd metatarsal heads , 4th and 
 5th metatarsal heads , and the heel showed significant differences among the angles ( table 1table 1.changes of foot pressure with the ankle angle of an afo 
 ( n / cm)05105hallux*253.847.2271.940.2277.174.8214.949.025th toes*103.317.789.929.684.613.8102.116.51st metatarsal head387.484.0350.189.6345.564.4387.164.92nd & 3rd metatarsal head*401.664.8432.360.4450.448.4321.245.24th & 5th metatarsal head*94.832.478.425.969.321.9102.316.3midfoot53.118.547.921.154.422.651.416.7calcaneal region*240.348.3260.944.4291.642.5246.137.9all values are the meansd . the values with different superscripts in the same column 
 are significantly different at the p<0.05 level according to tukey s post hoc 
 test . ) the post - hoc test showed that the hallux pressure significantly 
 increased as the ankle angle increased , the pressure of the 2nd5th toes and the 4th and 5th 
 metatarsal heads significantly differences between 0 and 5 , and 5 and 10 , and the 
 pressure of the 2nd and 3rd metatarsal head showed significant differences between the 
 values of 5 and 10 , and those of 0 and 5. the peak foot pressure of the heel at 10 was 
 significantly greater than those of the other angles ( table 1 ) ( p<0.05 ) . the values with different superscripts in the same column 
 are significantly different at the p<0.05 level according to tukey s post hoc 
 test . stroke patients may lack sufficient heel strike , push off , and toe clearance during gait , 
 so afos have often been prescribed to improve the stability of the ankle joints in stroke 
 patients with ankle instability , and they are considered a good method for maintaining 
 postural stability14 . the purpose of this 
 study was to determine the effect on plantar pressure during walking of afo with the ankle 
 joint angles usually prescribed for stroke patients : the neutral position ( 0 ) , 5 of 
 dorsiflexion ( 5 ) , 10 of dorsiflexion ( 10 ) , and 5 of plantar flexion ( 5 ) . a normal gait pattern transfers weight after heel contact with the ground by a heel - rocker 
 mechanism using eccentric and concentric contractions of the dorsiflexors . when the heel 
 makes contact , it maintains the center of gravity in the midline with some eversion8 , 14 , 15 . the results of this study show that the 
 center of pressure moved to the outside at 5 in the foot pressure distribution unlike 
 normal gait and body weight support heel side . it is an abnormal movement of the foot 
 considered to be continued , and it shows a similar pattern , but better than 5 at 0. the 
 results of this study confirm that gait has a negative effect on abnormal mechanical 
 movement of the ankle joint . however , the 5 and 10 afo ankle angles had positive effects on the gait patterns of 
 healthy adults , resulting in transfer of weight from the heel to the hallux ( big toe ) . this 
 result is consistent with the results of kim and park11 who reported that during one leg standing with afos with different 
 ankle angles , the afo angles correlated with balance performance , joint stability , and 
 postural control . a previous study demonstrated that appropriate control of the ankle joint 
 elicits an efficient gait pattern and energy consumption during gait , and this was confirmed 
 in the present study by measuring foot pressure1 , 
 2 , 12 , 16 , 17 . taken together these findings indicate that afos with appropriate ankle angles are needed 
 to control the stability of the ankle joint and muscle activation . although a limitation of 
 this study was the recruitment of healthy adults , we confirmed that the ankle angles of the 
 afos affected foot pressure and gait pattern during gait . the present results suggest that 
 the appropriate angle for afos was more than 5 and 10 when afos are prescribed by 
 clinicians . further studies will be required to determine the effects of afo angles on 
 stroke patients and patients with ankle instability .
[ purpose ] the purpose of this study was to investigate the effects of the ankle angle of 
 an ankle foot orthosis ( afo ) on foot pressure during the gait in healthy adults . 
 [ subjects ] sixteen healthy males with neither orthopedic nor neurological problems 
 participated in this study . 
 [ methods ] subjects walked on a walkway at a self - selected pace 
 with an afo set at four different ankle angles ( 5 , 0 , 5 , and 10 ) . 
 foot pressure was 
 measured randomly according to the ankle angle of the afo using an f - scan system . 
 three 
 trials were measured and averaged for data analysis . [ results ] the peak foot pressure of 
 the hallux , 2nd5th toes , 2nd and 3rd metatarsal heads , 4th and 5th metatarsal heads , and 
 the heel showed significant differences among the afo ankle angles : angles of 0 and 
 5 
 increased the foot pressure of the lateral legions , and the peak foot pressure of the heel 
 at an afo ankle angle of 10 was significantly greater than those of the other angles . 
 [ conclusion ] the ankle angle of the afo affected foot pressure and gait patterns during 
 gait . 
 the results suggest that the appropriate angle for an afo is between 5 and 10 when 
 afos are prescribed by clinicians .