falls are one of the leading injury - related accidents involving older adults whose muscular 
 strength , proprioceptive sense , and bodily coordination are compromised with aging1 . the elderly lack obstacle negotiation 
 capacity and are prone to trip over commonly encountered environmental barriers such as door 
 sills , pavement blocks , and safety bumps2 . 
 in a local community , 33% of elderly people were reported to experience falls , of which 
 42.4% suffered falls3 . individuals with a history of falls have fears of repeated falls , depression , and anxiety , 
 all of which lead to decreased physical activities4 . these negative experiences result in reduced physical capacity in 
 terms of muscular strength , bodily flexibility , and coordination , rendering the affected 
 elderly even more susceptible to falls in a vicious cycle5 . notably , elderly women are more at risk of secondary injury such as 
 severe fractures after falling than elderly men because of their low bone density after 
 menopause6 . interventions for fall prevention include exercise , education , environmental improvements , 
 and medication7,8,9 , of which exercise has been 
 used in fall prevention programs in many ways , as it takes less time and money to implement 
 and programs are easy to set up . carter et al.10 reported in a 
 bibliographical study on exercise intervention that exercise improved leg strength 44.4% and 
 balance ability 37.5% in older adults and that as weakness of muscle strength in the trunk 
 was more important than that in the lower extremities , strengthening of lumbar function can 
 improve functional stability , leading to increased balance ability , gait ability , and 
 prevention of falling11 , 12 . core stabilization exercise ( cse ) can improve balance control ability by reinforcing 
 intersegmental muscles in the multifidus , transversus abdominis , and rotators13 and physicopsychological functions in a 
 harmonious way by stimulating proprioception powerfully when it is accompanied by swiss ball 
 exercises , improving balance sense , and maintenance ability14 . previous studies on falling in elderly adults involving cse have 
 been limited to balance ability or gait ability15 , 
 16 , and there have been only a few 
 studies on obstacles as an environmental factor or psychological factors . therefore , this study evaluated changes in the physicopsychological functions of elderly 
 women with a fear of falling in negotiating obstacles such as a doorstep ( 5.2  cm ) of a 
 bathroom , where falling occurs frequently , through a performance - oriented mobility 
 assessment ( poma ) in order to understand whether cse is valid as an efficient exercise to 
 prevent and control falling in consideration of the physicopsychological functions of 
 elderly women . the subjects of the study were 20 elderly women above the age of 65 who were able to walk 
 independently , did not have experience participating in regular balance training more than 
 twice a week within the past 6 months , had a score higher than 24 on the mini - mental status 
 examination - korea ( mmse - k ) , had no limits on exercise performance due to visual or 
 musculoskeletal disorders and no previous experience of falling , and scored lower than 19 on 
 the tinetti poma17 . the purpose and 
 methods of this study were explained to all the participants , who read and signed an 
 informed consent from that revealed all the details of the study protocol , which were 
 approved by the ethics committee of kangwon national university ( no . the subjects selected were divided into an experimental group and a control group by 
 drawing lots , and the average age , height , and weight in the experimental group were 
 73.203.46  years , 152.154.29  cm , and 57.787.95  kg , while those in the control group were 
 71.003.50  years , 149.836.45  cm , and 53.8011.04  kg . there were no significant differences 
 among the groups with regard to age , height , or weight ( p>0.05 ) . the core stabilization exercise program proposed by jeffrey18 and hesari et al.19 was applied to the experimental group and cse was composed of three 
 steps . level 1 consisted of abdominal hollowing in a supine position , abdominal hollowing in 
 a prone position , abdominal hollowing in a quadruped position , abdominal hollowing in a 
 supine position while curling the feet , abdominal hollowing in a prone position while 
 curling the feet , and modified side bridging . level 2 consisted of bridging with abdominal 
 hollowing , pelvic bridging , the dying bug with abdominal hollowing , and abdominal hollowing 
 while seated on a swiss ball . level 3 consisted of pelvic bridging with a swiss ball , bird 
 dog exercise , twists on a swiss ball , and bird dog exercises on a swiss ball . the 
 experimental group performed a core stabilization program consisting of three levels for 
 30  min , three times per week on alternate days , for 6 weeks . this program consisted of three 
 levels , and the subjects began at exercise level 1 and proceeded to the next level according 
 to the protocol for the day . level 1 included static holds in a stable environment , level 2 
 included dynamic movements in a stable environment , and level 3 included dynamic movements 
 in an unstable environment , such as on a swiss ball , and resisted dynamic movements in an 
 unstable environment . before the program and 6 weeks after the program , the tinetti poma , crossing velocity ( cv ) , 
 maximum vertical heel clearance ( mvhc ) and knee flexion angle , which are related to physical 
 functions , were measured , and with respect to psychological functions , depression and fear 
 of falling were measured . the tinetti poma is an instrument used to decide the degree of 
 fear of falling and balance and mobility in elderly adults consisting of items scored on a 
 3-point scale . the maximum score is 28 , with 16 points for balance and 12 points for gait . if a subject scores below 19 , fear of falling is high , and scores of 19 to 24 indicate an 
 intermediate degree for fear of falling ; scores of 25 to 28 indicate no fear of falling . for 
 the crossing velocity ( cv ) , the horizontal distance from the point at which the leading limb 
 leaves the ground to the point at which the heel returns to the ground again is divided by 
 the time taken20 . for the maximum 
 vertical heel clearance ( mvhc ) , the vertical distance from the height of the obstacle before 
 obstacle negotiation to the ball of the leading limb was measured21 . the obstacle was 60  cm long , 
 10  cm wide , and 5.2  cm high . the subjects began their gait 5  m from the obstacle and 
 continued on 3  m after obstacle negotiation . cv and mvhc were measured with the use of dartfish 
 software ( dartfish , fribourg , switzerland)23 , and the results were output in a data table . to analyze 
 depression , the ces - d ( center for epidemiological studies - depression scale ) was used . it is 
 scored on a 4-point scale ( 03 ) , and includes a total of 20 questions . the higher the score , 
 the higher the depression24 . for fear of 
 falling , the fofq ( fear of falling questionnaire ) was used . it is scored on a 4-point scale 
 ( 14 ) and includes a total of 11 questions . the higher the score , the higher the fear of 
 falling25 . for statistical analysis of the results , spss 18.0 was used . to explain the differences in measurement variables 
 according to the measurement period between exercise groups , a 2-way anova with repeated 
 measure was used , and the level of statistical significance was =0.05 . repeated measure anova to analyze changes in the poma , cv , mvhc , kf , depression , and fof 
 according to the measurement periods showed that there was a statistically significant 
 difference in the interaction between time and the groups and that the changes in poma , cv , 
 mvhc , kf , depression , and fof according to time differed ( p<0.001 ) ( table 1table 1.changes in physical and psychological function variablesgroupbeforeafterpoma ( score)eg ( n=10)17.601.3419.301.57**cg ( n=10)17.801.4017.601.43cv ( m / sec)eg ( n=10)1.560.211.600.21*cg ( n=10)1.560.101.550.09mvhc ( cm)eg ( n=10)7.421.387.021.33*cg ( n=10)7.361.627.311.74kf ( angle)eg ( n=10)111.003.16108.604.06*cg ( n=10)110.803.77110.303.16depression ( score)eg ( n=10)27.103.6724.503.34**cg ( n=10)26.002.5825.203.00fear of falling ( score)eg ( n=10)22.501.4319.801.69*cg ( n=10)22.603.2721.903.54meansd . eg , experimental group ; cg , control group ; poma , performance - oriented 
 mobility assessment ; cv , crossing velocity ; mvhc , maximum vertical heel clearance ; kf , 
 knee flexion . eg , experimental group ; cg , control group ; poma , performance - oriented 
 mobility assessment ; cv , crossing velocity ; mvhc , maximum vertical heel clearance ; kf , 
 knee flexion . * p<0.05 ; * * p<0.01 older adults have low balance and stability due to physiological and functional decreases 
 that occur with ageing26 , and to 
 compensate for balance and stability in gait , cadence and stride length decrease27 . in the case of obstacle negotiation , when 
 the leading foot encounters obstacles , the center of the body moves forward and fear of 
 falling increases28 . in this case , the 
 mvhc , joint angle , and cv are important measures to assess the ability of elderly adults to 
 safely cross obstacles during gait5 , 29 , 30 . although falling is not always accompanied by physical injury , fear 
 of falling again can be used to predict falling in elderly adults5 . fear of falling leads to a decrease in activity and low 
 self - esteem for independent behavior4 and 
 has direct negative effects that result in decreased balance and gait disorder31 , 32 . cse is training to improve the stability of the trunk by inducing a correcting reaction and 
 an equilibrium reaction through balance training of the flexors and extensors , and as it has 
 been judged to have an effect on physicopsychological functions in obstacle negotiation , a 
 clinical study was conducted . the results of the present study showed that the tinetti poma , cv , mvhc , and knee flexion 
 angle were significantly improved . esculier et al.33 provided lumbar stability training through a wii fit program for 
 parkinson s patients for 6 weeks and administered the tinetti poma . chou et al.20 reported that the cv was slow for elderly adults with 
 lower balance ability . weerdesteyn et al.21 provided balance , gait , and coordination training for elderly 
 adults and reported that foot clearance decreased , which matched with the results of the 
 present study . park and lee22 reported 
 that the maximum knee flexion angle of normal adults with lumbar stability was significantly 
 lower in comparison with that of elderly adults with lumbar instability , which partially 
 matched with the results of the present study . the study by lee et al.34 , who reported that a falling prevention program decreased 
 the gds ( geriatric depression scale ) significantly , was in agreement with the study by duque 
 et al.35 , who reported that fear of 
 falling by elderly adults who experienced falling significantly decreased as a result of 
 balance training using a virtual reality system . such results indicate that stability of the trunk was secured , as cse decreased the sway 
 area of the center of mass . through harmonious exercise of the limbs based on physical 
 stability , the subjects could negotiate obstacles precisely and easily , had higher 
 self - esteem and had less fear of falling and depression . it is suggested that the 6-week cse 
 decreased excessive obstacle gait with physical instability in elderly women and improved 
 their physicopsychological functions involving obstacle gait .
[ purpose ] the aim of the present study was to investigate the effects of core stability 
 exercise ( cse ) on the physical and psychological functions of elderly women while 
 negotiating general obstacles . [ subjects and methods ] after allocating 10 elderly women 
 each to the core stability training group and the control group , we carried out 
 performance - oriented mobility assessment ( poma ) and measured crossing velocity ( cv ) , 
 maximum vertical heel clearance ( mvhc ) , and knee flexion angle for assessing physical 
 performances . 
 we evaluated depression and fear of falling for assessing psychological 
 functions . 
 [ results ] relative to the control group , the core stability training group 
 showed statistically significant overall changes after the training session : an increase 
 in poma scores , faster cv , lower mvhc , and a decrease in knee flexion angle . 
 furthermore , 
 depression and fear of falling decreased significantly . 
 [ conclusion ] cse can have a 
 positive effect on the improvement of physical and psychological performances of older 
 women who are vulnerable to falls as they negotiate everyday obstacles .