ankle joints have a complicated anatomical and mechanical structure , and can have develop , 
 which are among the most frequent injuries during normal physical activities1,2,3 .
ankle trauma can be categorized as acute or 
 chronic ; conservative treatment with rehabilitation training is crucial because chronic 
 lateral instability of the ankle hinders mobility and reduces ambulatory status and balance 
 capabilities4,5,6 .
frequent sprains of the 
 ankle joint are caused by loss of muscular stability or inappropriate treatments , and 
 collateral pain is reported as the most common cause7 .
patients with chronic ankle instability ( cai ) have reduced balance capabilities , making it 
 difficult to abruptly turn around or halt .
this functional instability is due to damage of 
 the mechanoreceptors in the joint region after ankle injury6 .
mechanical injuries can result in a limited range of motion , 
 anthropometric changes , ligament laxity , and degenerative changes4 , 5 , 8 .
therefore , appropriate rehabilitation to enhance mobility is 
 beneficial for the recovery of myofunction in both the general public and athletes2 , 9 . in 
 particular , patients with a severe reduction in proprioception due to an ankle sprain 
 require improvement in muscular strength and postural control10 , 11 . in this respect , 

resistance training is safe and effective in the prevention and rehabilitation of ankle 
 sprains with cai , and is a useful method for functional improvement12 .
complex training of major 
 joints should be performed efficiently14 , 
 and should result in pain relief , restoration of range of motion , recovery of muscle 
 strength and endurance , and improvement in postural control15 .
the present study was conducted to provide baseline data for an efficient rehabilitation 
 exercise program .
isokinetic muscular strength was analyzed after 8 weeks of a strategic 
 strength resistance exercise program in male subjects in their twenties who had pain or 
 functional damage in the ankle joint .
this study recruited 22 male subjects who were orthopedically diagnosed with a functional 
 injury of the ankle joint , and performed a strategic strength resistance exercise program 
 for 8 weeks . prior to enrollment ,
the purpose of this study and experimental methods were 
 disclosed to all subjects , and participants voluntarily gave their signed informed consent . 

the study was approved by the hufs university and the institution in which it was performed , 
 and complied with the ethical standards of the declaration of helsinki .
the average physical 
 characteristics of the participants were : age 26.414.16  years old , height 179.107.31  cm , 
 and weight 75.848.07  kg .
prior to the test , the degree of instability of each ankle joint was measured using the 
 ankle score scale ( ass ) , which is comprised of 8 subjective questions regarding pain , 
 swelling , instability , stiffness , stair - climbing , running , work activities , and support 
 ability .
the muscular mobility of plantar flexion and dorsiflexion in the ankle were measured using 
 isokinetic testing equipment ( humac norm testing and rehabilitation system , csmi solutions , 
 usa ) . to avoid hyperflexion or hyperextension injury during the test
, each subject set their 
 own range of motion by individual calibration , and the measurements were digitized and 
 quantitated using the software provided by the manufacturer . to analyze comprehensive 
 isokinetic myofunction in the ankle , values of peak torque at 30/sec and peak torque per 
 body weight
quadriceps ratio of 
 the ipsilateral thigh , peak torque of extension and flexion was measured , and the flexion to 
 extension value was converted to a percentile ( % ) .
the 8-week strategic strength resistance exercise program focused on the improvement of 
 muscular strength , proprioceptive ability , and functional ability to improve complex 
 instabilities of the ankle joint .
the training consisted of three sets per week , with a 
 total of 24 sets , at 60 minutes per set , and an increase in intensity every 2 weeks , 
 following the progressive overload principle .
in addition , the muscular strength program 
 consisted of weight training , plyometric exercises without a load , and thera - band exercises 
 to strengthen muscles in the lower limbs , such as the quadriceps , hamstring , and 
 gastrocnemius . exercises to enhance proprioceptive ability were performed to improve the 
 range of motion of the ankle joints , and props were used to improve static and dynamic 
 postural controllability .
, usa ) for windows . for all 
 measurements , the average and standard deviation were calculated , and a paired t - test was 
 adopted to test the differences in isokinetic myofunction ; a medical questionnaire was 
 complete before and after the 8-week strategic strength resistance exercise program . 

results from the medical examination by interview before and after the 8-week program are 
 shown in table 1table 1.results of the medical examination by interview regarding the ankle jointfactorsbefore programafter programpain15.00.017.82.6***swelling6.62.410.00.0***instability17.22.621.62.4***stiffness4.31.34.61.0stair climbing8.12.59.12.0running5.92.08.82.2***work activities10.31.310.61.7support ability4.31.35.00.0*total71.68.687.46.2***unit : point , values are the meansd , * p<0.05 , * * * p<0.001 . the overall scores for the 8 questions regarding the ankle joint before and 
 after participation in the program showed a statistically significant improvement 
 ( p<0.001 ) from 71.638.62 to 87.446.21 , respectively .
unit : point , values are the meansd , * p<0.05 , * * * p<0.001 peak torque measurements in plantar flexion and dorsiflexion of the ankle before and after 
 the 8-week program are shown in table 
 2table 2.measurements of the isokinetic peak torque of the anklesbefore programafter programpfright87.325.6118.528.5*left93.934.0112.729.3dfright25.95.834.16.9**left27.35.534.88.0*unit : nm , values are the meansd , pf : plantar flexion , df : dorsi flexion , * p 
 < 0.05 , * * p < 0.01 .
unit : nm , values are the meansd , pf : plantar flexion , df : dorsi flexion , * p 
 < 0.05 , * * p < 0.01 measurements of the peak torque per body weight in plantar flexion and dorsiflexion are 
 shown in table 3table 3.measurements of the peak torque / body weight of the 
 anklesbefore programafter programpfright124.838.3149.633.7left133.846.9142.739.7dfright37.19.143.47.8left39.68.744.59.2unit : % , values are the meansd , pf : plantarflexion , df : dorsiflexion .
the overall trend showed that the measurements increased , but this was not 
 statistically significant .
unit : % , values are the meansd , pf : plantarflexion , df : dorsiflexion analysis of the isokinetic hamstring : quadriceps ratio in plantar flexion and dorsiflexion 
 is shown in table 4table 4.analysis of the isokinetic hamstring : quadriceps ratio of the anklesbefore programafter programright29.34.932.212.9left31.98.133.216.0unit : % , values are the meansd . despite the lack of statistical significance , both the left and right ratios 
 increased in the post - program measurements .
weakness or unstable mobility in extension and flexion can cause instabilities in the major 
 joints of the lower limb17 .
patients with 
 cai have difficulty with fundamental physical activities such as postural control and gait 
 performance , and have limited functional activities , including postural sway ; there is a 
 risk of muscle injury because range of motion is decreased due to weakening and imbalance of 
 lower limb strength6 .
the prevention of 
 instability using self - evaluation with a medical questionnaire is desirable because 
 untreated instability can induce abnormal external forces on the ankles , repeatedly 
 resulting in an increase in instability factors18 . a medical examination by interview and the functional ankle instability questionnaire
this study showed that an 8-week strategic strength resistance 
 exercise program significantly improved pain , swelling , instability , and support ability of 
 the ankle joint , as well as other factors that stabilized following the program .
isokinetic strength testing mostly measures strength exhibition and balance ratios in the 
 lower limb , and can be utilized for predicting isokinetic strength , relative diagnosis , and 
 the possibility of occurrence20 .
studies 
 conducted on strength , balance , and functionality have revealed that weakening of the ankle 
 joint can worsen functional instability and the possibility of reinjury21 , and that a combined exercise program is beneficial in the 
 improvement of complex instability of the lower limb22 .
in addition , studies have shown that strength of plantar flexion 
 is significantly different between jazz dance and ballet at an angular speed of 120/sec , 
 while strength of dorsiflexion is significantly different between jazz dance and ballet at 
 an angular speed of 30/sec23 .
another 
 study reported that dorsiflexion strength is higher in a concentric exercise group compared 
 with an eccentric exercise group , when 12 male athletes with chronic ankle sprain were 
 treated with 8-week isokinetic exercise programs24 . despite the differences in experimental methods , the majority of 
 the results of previous studies that investigated abnormalities of ankles are consistent 
 with the results of the present study . in the present study , a medical examination by interview
was performed and the change in 
 isokinetic strength of the ankle was measured before and after a strategic strength 
 resistance exercise program .
peak torque , relative strength , and isokinetic 
 hamstring : quadriceps ratios for right plantar bilateral dorsiflexion increased .
notably , the 
 differences in the answers to the medical questionnaire and the peak torque were 
 statistically significant .
thus , a strategic strength resistance exercise program is necessary for the functional 
 stability of the ankle joint , and active treatments are recommended to prevent or treat 
 chronic impairments .
strategic and efficient exercise intervention programs are needed to 
 maintain strength in ankle joint reinjury .
 [ purpose ] the purpose of this study was to investigate the effects of a strategic 
 strength resistance exercise program on the isokinetic muscular function of the ankle 
 joint . 
 [ subjects ] this study included 22 males in their twenties who were diagnosed with 
 functional injury of the ankle joint . [ methods ] to strengthen plantar flexion and 
 dorsiflexion of the ankle joint , 8 weeks of weight , resistance band , and plyometric 
 training , and training using props were performed . 
 [ results ] a medical examination by 
 interview indicated that pain , swelling , instability , running , and support capacity of the 
 ankle joint significantly improved with the strategic strength resistance exercise 
 program . for the isokinetic peak torque of the ankles , significant differences were 
 observed in right plantar flexion and bilateral dorsiflexion . 
 [ conclusion ] the strategic 
 strength resistance exercise program is highly recommended for the functional stability of 
 the ankle joint . 
 efficient exercise therapy is useful for muscle damage prevention , muscle 
 strengthening , and functional interventions . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION