Gait instability out-patients consultation in the Elderly: interests of simple and dual task gait analysis
Dr Bernard AUVINETa, Dr Claude TOUZARDb, Prof Vincent GOËBc
a Polyclinique du Maine, b Hôpital de Laval, c CHU Amiens
Introduction: Gait instability may be the first step towards risk of falling, exposure to dementia, and disability . Gait analysis under Single Task (ST) measures the locomotor capacity and quality; and under Dual Task (DT) the cognitive reserve.
Methods: Data were collected from an out-patients consultation dedicated to gait instability. A ST and DT (counting backwards one by one from fifty) gait analysis (Locometrix) was carried out for each patient. Under ST gait variables included: walking speed (m/s), cadence (Hz), cranio-caudal power (W), gait regularity (which measures the similarity of successive strides (dimensionless)). The dual task cost (DTC) was calculated for walking speed, cadence and regularity according to the formula: DTC(%) = 100* (ST-DT)/ST.
Results: 103 patients were recruited (58F; 45M), age (76±7y); BMI (25±4); MMS (26.5±3.3). Patients can be divided into 4 specific complaints: gait instability (n=46), recurrent falls (n=30); memory impairment (n=19) and senile gait (n=8). Gait analysis under ST provides information for gait analytic motor rehabilitation. Under DT conditions gait analysis: identifies cognitive involvement in gait disturbances, may explained recurrent falls, and helps to identify Mild Cognitive Impairment subtypes (amnestic and non-amnestic).The DTC were 14.7±12.0%, 11.1±9.7%, 21.1±22% for walking speed, cadence and regularity respectively. There were no differences between genders, neither for each gait variable. From DTC specific motor phenotypes were identifying, and thus tailor motor-cognitive rehabilitation can be proposed; they may be in relation to specific physio-pathology mechanisms.
Conclusion: Gait analysis under ST and DT conditions seems to be part of a Gait Instability out-patients consultation in the Elderly. These two measurements help to diagnosis, prognosis and tailor the motor-cognitive rehabilitation. Further cohort studies (patients and controls) have to be carried out for identification of DTC threshold for each gait variable.
1. Montero-Odasso M. Gait and cognition: a complementary approach to understanding brain function and the risk of falling. JAGS 2012; 60: 2127-36.
Keywords : gait instability,elderly, gait analysis