motor control changes in trunk muscles after using anatomical posture control orthosis in the elderly hyperkyphotic subjects

Introduction: hyperkyphosis is known to interfere with the normal function of thetrunk musculature in the elderly. although the effectiveness of orthoses in improvingposture and balance in hyperkyphotic elderly people has received much attention, theeffect of an orthosis on motor control of muscles remains unknown. this study aimed toevaluate changes in motor control strategies of trunk muscles during walking in elderlyhyperkyphotic subjects after using an anatomical posture control (apc) orthosis.materials and methods: a total of 19 elderlies (11 women and 8 men) withthoracic hyperkyphosis of more than 45 degrees were enrolled in the study. surfaceelectromyography (emg) signals were recorded from 6 trunk muscles bilaterallywith and without orthosis. the voluntary response index (vri) was calculated fromquantitative analysis of surface electromyography (semg) data during level walking inthose with and without orthosis. the outcome variables of vri included the similarityindex (si) and electromyographic magnitude (mag) of muscle groups. the effects ofapc orthosis on trunk motor control were tested using a wilcoxon non-parametric test.cohen’s d effect sizes were also calculated.results: a significant improvement was observed (p<0.05) in mag and response vector(rv) of five muscles from the right and left sides and the vri increased significantlyafter using this posture control orthosis (p<0.05; effect size [es]: 0.27).conclusion: improving trunk motor control after using orthosis, with relatively mediumeffect sizes, was observed in the elderly with hyperkyphosis during walking.