Smoothness of Gait in Healthy and Cognitively Impaired Individuals: A Study on Italian Elderly Using Wearable Inertial Sensor

Abstract

The main purpose of the present study was to compare the smoothness of gait in older adults with and without cognitive impairments, using the harmonic ratio (HR), a metric derived from trunk accelerations. Ninety older adults aged over 65 (age: 78.9 ± 4.8 years; 62% female) underwent instrumental gait analysis, performed using a wearable inertial sensor and cognitive assessment with the Mini Mental State Examination (MMSE) and Addenbrooke’s Cognitive Examination Revised (ACE-R). They were stratified into three groups based on their MMSE performance: healthy controls (HC), early and advanced cognitive decline (ECD, ACD). The spatio-temporal and smoothness of gait parameters, the latter expressed through HR in anteroposterior (AP), vertical (V) and mediolateral (ML) directions, were derived from trunk acceleration data. The existence of a relationship between gait parameters and degree of cognitive impairment was also explored. The results show that individuals with ECD and ACD exhibited significantly slower speed and shorter stride length, as well as reduced values of HR in the AP and V directions compared to HC, while no significant differences were found between ECD and ACD in any of the investigated parameters. Gait speed, stride length and HR in all directions were found to be moderately correlated with both MMSE and ACE-R scores. Such findings suggest that, in addition to the known changes in gait speed and stride length, important reductions in smoothness of gait are likely to occur in older adults, owing to early/prodromal stages of cognitive impairment. Given the peculiar nature of these metrics, which refers to overall body stability during gait, the calculation of HR may result in being useful in improving the characterization of gait patterns in older adults with cognitive impairments.

Deterioration, Compensation and Motor Control Processes in Healthy Aging, Mild Cognitive Impairment and Alzheimer’s Disease

“…It is now notoriously known that mobility capacities also are worse in AD and MCI populations than age-matched cognitively unimpaired older adults. Overall, studies have reported slower gait speed, as well as a shorter and more variable stride [ 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 ]. Balance and postural control are also impaired [ 77 , 78 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 ], and kinematic studies investigating handwriting and finger-tapping movements have reported fine motor control deterioration in MCI and AD patients [ 96 , 97 , 98 , 99 , 100 ].…”

“…Studies have shown that modifications of sensorimotor functions may precede the onset of dementia [ 91 , 107 , 108 ] and that the presence of motor dysfunction could predict adverse outcomes in AD patients, such as fall risk [ 9 , 10 , 11 , 12 , 13 , 14 , 84 , 85 , 108 , 109 , 110 , 111 ]. In MCI, studies have also reported that motor function impairments are predictive of a higher risk of developing AD [ 79 , 98 , 108 , 112 ].…”

“…Because motor deficits, or at least their detection, seem to precede cognitive impairment, one could use them as predictive diagnostic tools [ 84 , 91 , 98 , 113 ]. For example, in a recent study, Ehsani et al (2020) asked MCI patients, AD patients, and healthy controls to execute repetitive elbow flexion on a dual task (counting backward by ones and threes).…”

Functional Electrical Stimulation for Foot Drop in Post-Stroke People: Quantitative Effects on Step-to-Step Symmetry of Gait Using a Wearable Inertial Sensor

“…The HR is based on a spectral analysis of the acceleration signals and is related to the bilateral rhythmicity of movement, based on the measure of trunk acceleration during a stride that is expected to be formed by two alternating symmetric steps; it provides different kinds of information with respect to the traditional spatio-temporal parameters, which are focused on the lower limb symmetry at the distal level [ 22 ]. Recent studies demonstrated that the HR parameter is worthwhile in quantifying gait alterations associated with neurologic and orthopedic conditions, such as older people [ 23 ], Parkinson’s disease patients [ 22 ], multiple sclerosis [ 24 ], normal weight and obese children/adolescents [ 25 , 26 ], Prader–Willi patients [ 27 , 28 ], and cognitively impaired individuals [ 29 ]; in several cases, it is able to reveal subtle changes in gait that might occur well before they become detectable in terms of conventional spatio-temporal parameters [ 22 , 24 , 25 , 26 , 30 ]. Furthermore, it must be emphasized that trunk accelerations could be easily recorded by a single sensor in clinical settings or in other ecological contexts, without the limitations of a movement analysis laboratory, which requires expensive equipment, long setup times, and time-consuming post-processing procedures [ 26 , 28 , 30 , 31 ].…”

Will We Do If We Can? Habitual Qualitative and Quantitative Physical Activity in Multi-Morbid, Older Persons with Cognitive Impairment

“…The independent association of step-to-step symmetry with duration and frequency of walking may relate to typical deficits of older persons with CI, such as lower levels of PA performance [ 3 ] and a lower step-to-step symmetry [ 86 ], or the high association between step-to-step symmetry and walking balance [ 87 , 88 ], as a basic precondition of walking and thereby leading to a higher duration and frequency of walking.…”