ankle sprain occurs more often in active movements such as walking , running , and jumping . 
 among lower limb injuries , ligament injuries of the ankle account for more than 50% of the 
 cases .
furthermore , at least 7% of people with ankle sprain had additional repetitive 
 symptoms , including re - injuries and functional anomalies1 .
re - injury of ankle sprain triggers chronic ankle instability ( cai ) , 
 which acts as a cause for recurrent sprains in 5572% of the cases .
these patients with 
 re - injuries complained of residual symptoms for 6 to 18 months2 . in this way , many previous studies reported a high recurrence rate 
 of ankle sprain3 , 4 and attributed the causes of this high recurrence rate to deformed 
 tissues around the ankle joint , loss of proprioceptive sense5 , and reuse of the ankle joint before complete recovery .
cai refers to the repetition of lateral 
 ankle joint instability after an initial lateral ankle ligament sprain , with residual 
 symptoms such as pain , edema , and giving way of the ankle joint6 .
furthermore , the greatest causes of repetitive ankle sprain 
 were reported to be the muscular weakness of the tibialis anterior and peroneus longus , and 
 the increased ankle instability due to the hypofunction of the proprioceptive sense7 , 8 . in 
 addition ,
when the instability of the ankle joint increases , other motion patterns are 
 required to compensate for the instability , which causes the motion deformations of the hip 
 joint and trunk , resulting in the side effect of the changed anatomical arrangement9 .
kim eun - kyung10 claimed that rehabilitation exercise treatment programs 
 such as muscle strengthening , kidney , and proprioceptive sense enhancement exercises are 
 required to prevent and treat the chronic pain and functional ankle joint instability after 
 ankle joint sprain .
a rehabilitation exercise through 4-week balance training has been also 
 reported to elicit significant changes in the lower leg rotation and hindfoot angle11 .
odriscoll et al.12 reported that functional rehabilitation exercises for 6 
 weeks , including muscle - strengthening exercise , balancing exercise , and agility and jump 
 training caused significant changes in balancing ability and hindfoot angle .
therefore , an 
 appropriate functional rehabilitation program should be applied to improve chronic ankle 
 joint instability by reinforcing the muscular function of the ankle joint and enhancing the 
 proprioceptive sense in patients with chronic ankle sprain .
hence , in this study , an ankle 
 functional rehabilitation exercise was applied to patients with chronic ankle sprain and its 
 effects on ankle joint fms result and isokinetic muscular function were examined .
this 
 presents a new alternative to the functional rehabilitation exercise program for the 
 prevention and rehabilitation of ankle sprain for patients with chronic ankle sprain .
the subjects of this study were 16 patients with chronic ankle pain and chronic ankle 
 sprain whose chronic cai had been diagnosed by medical examination , simple radiological 
 examination , computed tomography , and magnetic resonance imaging .
they were randomized to 
 the ankle functional rehabilitation exercise group ( afreg ; n=8 ) and control group ( cong ; 
 n=8 ) .
for the physical characteristics of the subjects , the mean age , height , and weight of 
 the afreg were 20.8  0.5  years , 174.6  7.1  cm , and 69.6  9.03  kg .
those of the cong were 
 20.7  1.1  years , 174.1  6.5  cm , and 66.2  7.6  kg . after receiving an explanation of the 
 intent and purpose of this study
the 
 two groups had no problem in homogeneity because they had no significant intergroup 
 differences in physical characteristics .
the ankle functional rehabilitation exercise 
 program mainly consisted of a proprioceptive sense exercise program , which was performed in 
 a total of 12 times , 6 times per week for 2 weeks , with an exercise time of 60 minutes .
the 
 ankle functional rehabilitation exercise program used the exercise tools for proprioceptive 
 sense exercise , jumper ( togu , germany ) and togu ( togu , germany ) . in detail , the exercise 
 items were ( 1 ) balance squat and ( 2 ) supine pelvic lift , performed while standing on the 
 jumper , and ( 3 ) lunge and ( 4 ) dorsi and plantar flexion , performed by weight bearing while 
 standing on the togu .
the exercise time was maintained at 30 seconds per set , during which 
 isometric training was performed .
for the fms related to ankle joint , deep squat , hurdle 
 step , and in - line lunge tests were performed in relation to the ankle joint functional 
 movement in 7 patterns by using the fms test kit ( usa ) , which is a functional motion 
 inspection measurement system . for the ankle joint isokinetic muscular function inspection , 

the peak torque ( nm ) at the angular speed of 240 was measured by using cybex humac norm 
 ( ankle joint system , usa ) .
the measured data were analyzed by using the spss 21.0 
 statistical program for windows .
a paired - test was conducted for comparison of the groups 
 between before and after the application .
all of the subjects understood the purpose of this study and provided written informed 
 consent prior to their participation in accordance with the ethical standards of the 
 declaration of helsinki .
in the ankle joint fms , the afreg showed significant improvements in all the fms items 
 after application ( p<0.05 ) , and the cong did not show any significant changes after the 
 application ( table 1table 1.the comparison of ankle joint of fms in the each group ( unit : nm)groupmuscle strengthpre ( mean  sd)post ( mean  sd)afregdst*1.6  0.52.5  0.5hst*1.8  0.32.7  0.4ilt*2.0  0.02.8  0.3congdst1.7  0.41.7  0.4hst1.8  0.32.1  0.9ilt2.0  0.02.3  0.5*p<0.05 ; afreg : ankle functional rehabilitation exercise group ; cong : control 
 group ; dst : deep squat test ; hst : hurdle step test ; ilt : in - line lunge test ) . * p<0.05 ; afreg : ankle functional rehabilitation exercise group ; cong : control 
 group ; dst : deep squat test ; hst : hurdle step test ; ilt : in - line lunge test for changes in the ankle joint isokinetic muscular functions , the afreg showed significant 
 improvements in every item after application ( p<0.05 ) , whereas cong did not show any 
 significant changes after application ( table 
 2table 2.the comparison of ankle joint of peak torque in the each group ( unit : nm)groupmuscle strengthpre ( mean  sd)post ( mean  sd)afregadfr*27.2  6.934.7  12.4adfl*25.5  7.033.7  9.7apfr*41.6  14.464.6  9.8apfl*40.1  13.859.2  13.0congadfr31.0  10.628.1  7.0adfl28.7  10.129.1  8.1apfr38.6  11.350.8  19.0apfl42.7  10.752.5  21.6*p<0.05 ; afre : ankle functional rehabilitation exercise group ; cong : control 
 group ; adfr : ankle dorsi flexion right ; adfl : ankle dorsi flexion left ; apfr : ankle 
 plantar flexion right ; apfl : ankle planter flexion left ) . * p<0.05 ; afre : ankle functional rehabilitation exercise group ; cong : control 
 group ; adfr : ankle dorsi flexion right ; adfl : ankle dorsi flexion left ; apfr : ankle 
 plantar flexion right ; apfl : ankle planter flexion left
the cai generates structural changes of the soft tissues around the ankle due to repetitive 
 ankle sprains and causes dysfunction in the stability of ankle neuromuscular control and in 
 musculoskeletal stability13 . among the 
 problems in patients with chronic ankle sprain
furthermore , scott15 reported that 
 functional rehabilitation exercise more effectively reduced pain and edema than surgery and 
 fixation .
another previous study also reported that functional rehabilitation exercise 
 through the training of proprioceptive sense decreased the re - injury rate of the ankle16 . recently , active research is being 
 conducted to present the directions of functional rehabilitation exercise , and studies on 
 the evaluation of functional rehabilitation exercise are being conducted as well17 .
this study was conducted to demonstrate that chronic ankle sprain is caused by chronic 
 dysfunction and instability of the ankle joint , and the muscular function and stability of 
 the ankle joint were improved through the application of ankle functional rehabilitation 
 exercise .
the afreg showed significant improvements in all items of the fms and ankle joint 
 isokinetic muscular function after application ( p<0.05 ) , whereas the cong showed no 
 significant changes after application .
the fms ( functional movement screen ) is known to be 
 useful for evaluating asymmetries of the body and defects in functional exercise motions 
 based on the basic motions of the proprioceptive sensory receptor , stability , and mobility , 
 which are the motion patterns of the body18 , 19 .
thus , it was used as a measurement item 
 in this study . in this study , by using this fms evaluation method , the functional defects of the ankle 
 were chosen as the measurement items before and after exercise . furthermore , the isokinetic 
 measuring instrument is an effective tool for evaluating muscular function because it can 
 produce the maximum muscular force according to the resistance within the predefined range 
 of motion of the joint .
hence , in this 
 study , an isokinetic instrument was used to measure the effects of the functional 
 rehabilitation exercise program on the improvement of muscular functions .
functional rehabilitation exercise is an integrated form of training for muscular strength , 
 agility , proprioceptive sense , and special exercise functions and refers to various patterns 
 of exercise programs .
it has been shown to effectively decrease pain and dysfunction . 
 furthermore , it has the effect of protecting tissues from many physical burdens applied 
 during physical activities by increasing the reaction speed of surrounding muscles and nerve 
 tissues , restoring stability , and reinforcing muscles21 .
in addition , an 8-week functional rehabilitation program , including proprioceptive 
 exercise , helped the stabilization of the unstable ankle joint by improving postural sway 
 and isokinetic muscular function ( isokinetic strength)22 .
an ankle joint balance improvement exercise program was effective 
 in the rehabilitation and prevention of chronic ankle instability and sprain , and the 
 control of proprioceptive ability protected the body from injuries11 .
in the application of rehabilitation exercise program for resolving functional ankle 
 instability , the combined application of muscle strengthening and proprioceptive exercises 
 was more effective than muscle strengthening exercise alone22 . besides , because ankle instability is caused by the combination of 
 the lack of proprioceptive sense and eversion muscle weakening , rehabilitation programs must 
 focus on the improvement of the proprioceptive sense and muscular strength23 .
furthermore , both improved proprioceptive 
 sensibility and the functional capabilities of the surrounding muscles of the ankle joints , 
 thereby providing a coping mechanism for the unexpected inversion of ankle joints24 . therefore ,
the ankle functional rehabilitation program applied in this study was mainly 
 composed of the exercise of proprioceptive sense in order to achieve the stability of the 
 affected site by recovering the motion control ability while reinforcing the muscular 
 strength of the patients with chronic ankle sprain .
the improvement was achieved as a result 
 of the improved muscular functions of the muscles comprising the ankle joint and the 
 improved integrated system of the muscles and nerves that support balance and enables the 
 exhibition of stable forces through the integration of the proprioceptive receptor and 
 motion sensory nerves by the muscles around the trunk , pelvis , and abdomen .
consequently , the application of ankle functional rehabilitation exercise in patients with 
 chronic ankle sprain in this study will present a new alternative solution as an effective 
 rehabilitation program for the reinforcement of ankle joint fms and isokinetic muscular 
 function .
 [ purpose ] this study was conducted to investigate the effects of ankle functional 
 rehabilitation exercise on ankle joint functional movement screen results and isokinetic 
 muscular function in patients with chronic ankle sprain patients . 
 [ subjects and methods ] 
 in this study , 16 patients with chronic ankle sprain were randomized to an ankle 
 functional rehabilitation exercise group ( n=8 ) and a control group ( n=8 ) . 
 the ankle 
 functional rehabilitation exercise centered on a proprioceptive sense exercise program , 
 which was applied 12 times for 2 weeks . to verify changes after the application , 
 ankle 
 joint functional movement screen scores and isokinetic muscular function were measured and 
 analyzed . [ results ] 
 the ankle functional rehabilitation exercise group showed significant 
 improvements in all items of the ankle joint functional movement screen and in isokinetic 
 muscular function after the exercise , whereas the control group showed no difference after 
 the application . 
 [ conclusion ] the ankle functional rehabilitation exercise program can be 
 effectively applied in patients with chronic ankle sprain for the improvement of ankle 
 joint functional movement screen score and isokinetic muscular function . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION