Anne-Marie Ferrandez

Slowness in elderly gait

The aim of this research was to better understand how gait slows with age. We analyzed the kinematic parameters of locomotion (velocity, stride length, cycle duration, swing and double support durations), and their interrelationships both in the slowing process due to aging and in intentional modulations of velocity. The experiments were carried out on a group of 67 elderly adults (aged 60 to 80+) walking with a free gait and a fast gait. This group was compared to a young population in equivalent situations. The results show that the main characteristics of the elderly gait are the shortening of strides and the increasing of the double support phase. However, these properties seem to be due to the slowness of the elderly gait more than to more specific alterations affecting this population since identical features were also observed in the slow gait of the young subjects. Furthermore, the ability to intentionally modulate velocity observed in this study was not altered by aging. These results suggest that elderly gait can be said to be normal if one takes the velocity into account.

Unintentional modulations of human gait by optical flow

Visual whole-field motion is known to trigger motor responses which minimize retinal slip (VOR, OKN and control of balance). In locomotion, however, the retinal slip is utilized to control the velocity and direction of displacement. The present experiment was aimed at determining how the velocity of optical flow affects the regulation of locomotion. Unintentional modulations in velocity, stride length and cadence were analyzed using a task in which artificial optical flow gave the subjects the impression they were walking at a different speed than they actually were. Slight but systematic modifications in locomotion were observed: experimental variation of the optical flow resulted in a decrease in stride length. None of the subjects were aware of this decrease, despite the fact that their muscular and articular afferences provided them with supraliminal information. Although visual flow velocity is usually a direct consequence of walking velocity, experimental modifications of visual flow were found here to cause unintentional modulations in locomotor parameters (stride length and cadence) more than in their product (velocity).

Static or dynamic predictors of physical activity (PA)? A tracking study based on 12- and 38-month follow-ups in older adults

Studies that investigated stability of PA in older populations are scarce. Moreover, no studies used dynamic indicators to predict PA trajectories. The purpose of the present study were to investigate PA stability overtime, and to examine if changes in self-reported physical function (dynamic indicator) are better predictors of trajectories of PA than baseline measures of physical function (static indicator). This is a prospective postal survey with two time-point follow-ups: 12 and 38 months. Participants were older adults aged ≥ 60 years, and members of the medical insurance scheme of the French national education system. They responded to a self-report questionnaire on PA and general health status at three different times: baseline, 12- and 38-month follow-ups (n=243 for the 12-month follow-up; n=164 for the 38-month follow-up). Overtime analyses of PA showed a moderate-to-good stability with regard to both duration and volume of PA; however, a decrease in stability for vigorous PA was found between 12- and 38-month follow-ups. Both baseline measure and changes in physical function predicted PA trajectories, but magnitudes of associations were stronger for the dynamic indicator. Moreover, change in physical function was the only predictor of both becoming active compared with Inactive (reduced probability) and becoming inactive compared to Active (increased probability). In conclusion, a dynamic indicator of physical function is a better predictor of PA variation than static indicators.

A note on modulations and structuring of locomotion in children and adults.

The aim of this study was to investigate the modulations of locomotion induced by a rhythmic cognitive task (counting ones steps). Subjects (6- and 8-year-olds and adults) were requested to walk freely, and then to walk while counting their steps. Here a decrease in cadence values was observed in children only, with quasi-total repercussions on velocity at the age of 6 only. The spatiotemporal structuring of locomotion described here is already present at 6 years of age and is not altered in the step-counting situation: strong links were observed between cadence and velocity, and between stride length and velocity, and weak links between cadence and stride length.

Use of care and the oral health status of people aged 60 years and older in France: results from the National Health and Disability Survey

Objective We aimed to analyze, from the data in a national survey, the use of oral care and the oral health status of patients living at home or in an institution. Background Patients aged 60 years and older have important oral health needs, but their oral management may differ according to their immediate environment. The fact of living at home or in an institution can influence the use of care and alter the patients’ perception of their oral health status. Methods The data analyzed were taken from a survey on disability and health carried out in 2008–2009, which is representative of the population living in France. It consists of two sections, one centered on disability and health among home-dwellers and the other on patients living in an institution. In each of these two populations, we carried out descriptive analysis of three themes: use of care, forgoing of care, and oral health. Results Although visits to physicians and specialists were frequent, visits to dentists were lower in both populations. While a minority of patients forwent care, it was dental care that was mainly forgone by both home-dwellers and institutionalized patients. The cost factor remained the principal reason, but other factors such as fear or accessibility problems were cited. Use of a dental appliance was considerably more frequent among institutionalized patients than among home-dwellers, with just over half the institutionalized population wearing a dental appliance. Perceived state of oral health remained difficult to interpret. Conclusion To improve access to oral care for the elderly, the patients, their entourage and health providers need increased awareness and information on the importance of good oral health. Better information must be associated with regular clinical examination.