Lower extremity kinematic comparisons between patients with mild cognitive impairment and healthy individuals during single and dual tasks

Abstract

AbstractBackgroundMild cognitive impairment (MCI) is one of the common health issues in modern societies, and it has a high rate of progression to dementia. Studies have shown that MCI has the potential to cause abnormal postural control and altered intersegmental coordination during functional activities, which may be one of the causes that lead to the increase of the risk of falls. The study aimed to compare the kinematics of the lower limb joints between patients with MCI and healthy controls during single‐task (gait) and cognitive or motor dual‐tasks (gait with arithmetic subtraction or tray handling).MethodSeventeen patients with MCI (age: 67.6±3.9 yrs; BMI:23.5±3.7) and seventeen healthy individuals (age: 67.9±3.7 yrs; BMI:24.0±4.2) were recruited in the study. Each participant performed single‐task (gait), cognitive dual tasks (gait while conducting arithmetic subtraction), and motor dual tasks (gait while balancing a ball on a tray), and the movements were recorded by a standard motion capture system. Peak angular magnitudes of the hip, knee, and ankle in the sagittal plane were extracted. Differences between the MCI and control groups were defined by independent t‐tests with a significant level at 0.05.ResultsThe significant differences between groups were found at the hip joint but not at the knee and ankle joint in all single‐ and dual‐tasks conditions. Compared to the healthy group, the MCI group demonstrated less maximum hip flexion and greater hip extension during the stance phase and less maximum hip flexion during the swing phase. The hip kinematics difference might be a change of the control of hip and pelvis muscles due to MCI thus altering the hip kinematic performance. This may also explain the increasing fall risks in patients with MCI due to this altered hip control strategy.ConclusionIn summary, the patients with MCI may have an alternative hip kinematic adaptation that is different from the healthy individuals. However, the cause of this adaptation is not clear at this point, and further investigation is necessary to make sure whether this is an important biomechanical marker or not.