Correlation Between Knee And Ankle Proprioception And One-leg Standing Posture Control Ability And Age-related Differences

Objective This study aimed to analyze the trend of knee and ankle proprioception with age and the effect of age on one-leg standing(OLS)postural control at different support surfaces based on inertial sensors;to investigate the correlation between knee and ankle proprioception and one-leg standing postural control,and the effect of increasing age on this correlation.Methods One hundred and fifty healthy subjects were recruited from a tertiary hospital in Beijing,including 51 subjects in the young group(18-44 years old),45 subjects in the middle-aged group(45-59 years old)and 54 subjects in the old group(60-80 years old).The proprioception of knee joint and ankle joint was tested by joint position angle reconstruction(JPR),and the sway of center of gravity during one leg standing on flat ground,one leg standing on forward plane and one leg standing on backward plane was recorded by posture sensor.Ten subjects from each of the three age groups were selected for the proprioception and one-leg standing test with a desensitization period of 2 weeks.Results(1)Proprioceptive sensitivity decreased with age,knee joint proprioception decreased substantially after 60 years of age(p<0.05);ankle proprioception decreased significantly after 50 years of age,but there was no statistical significance(p>0.05).(2)In one-leg stance on a flat surface,the acceleration extremes in both anterior-posterior and left-right directions of swing were lower in the youth group than in the middle-aged and elderly groups,with statistically significant differences(p<0.05),while there were no significant differences between middle-aged and elderly(p>0.05).The acceleration extremes in the anterior-posterior and left-right directions of oscillation in the forward and posterior inclined plane OLS states increased with age in the youth,middle-aged and elderly groups,and the differences between the groups were statistically significant(p<0.05).(3)In the young group,the absolute value of proprioceptive error of knee joint was positively correlated with the extreme value of Acc of forward and backward swinging under the condition of OLS(r=0.410,p < 0.0l),but there was no significant correlation between other indexes(p > 0.05).In the middle-aged group,there was a significant positive correlation between the absolute value of proprioceptive error of knee joint and ankle joint and the index of OLS posture control in three states(p < 0.05,p < 0.01).In the elderly group,the absolute value of proprioceptive error of knee joint was significantly correlated with the four indexes of flat OLS(p < 0.05,p < 0.01),but not with that of inclined OLS(p >0.05).The absolute value of proprioceptive error of ankle joint was significantly correlated with the postural control ability of OLS in all three states(p < 0.05,p <0.01).(4)In each of the three OLS states,10 sensor indexes were significantly correlated with age and gender(p < 0.05,p<0.01),3 indexes were significantly correlated with BMI(p < 0.05,p<0.01),and 1 index was significantly correlated with sports injury(p<0.05).(5)The ICC of the absolute error for the knee at 30° extension and the ankle at 10° dorsiflexion was greater than 0.75(p < 0.0l);the ICC of absolute error for other indexes was greater than 0.60(p < 0.0l).(6)The ICC values of Acc extreme in the anterior and posterior direction in the flat OLS state was 0.63(p<0.01),with good retest reliability;the ICC value of trunk Euler angle and center of gravity acceleration RMS under one-leg standing on the flat and inclined surfaces were0.71-0.87(p<0.01),with good retest reliability.Conclusion(1)There may be variability in the effects of ageing on knee and ankle proprioceptive function,and the target age of decline in proprioception may be different for the two joints,with knee proprioception declining substantially after age60.(2)The difference of standing on one-leg standing between different age groups on the slope is more significant,that is,the standing task of the slope is more sensitive to ageing-induced declines in balance.(3)The knee proprioception may also play a compensatory role in adjusting the one-leg standing posture control on the flat ground and inclined plane,especially in the middle-aged and the elderly.(4)The joint position sensation test based on inertial sensor is reliable and can measure the effect of aging on proprioception.