Gait variability: methods, modeling and meaning

The study of gait variability, the stride-to-stride fluctuations in walking, offers a complementary way of quantifying locomotion and its changes with aging and disease as well as a means of monitoring the effects of therapeutic interventions and rehabilitation. Previous work has suggested that measures of gait variability may be more closely related to falls, a serious consequence of many gait disorders, than are measures based on the mean values of other walking parameters. The Current JNER series presents nine reports on the results of recent investigations into gait variability. One novel method for collecting unconstrained, ambulatory data is reviewed, and a primer on analysis methods is presented along with a heuristic approach to summarizing variability measures. In addition, the first studies of gait variability in animal models of neurodegenerative disease are described, as is a mathematical model of human walking that characterizes certain complex (multifractal) features of the motor control's pattern generator. Another investigation demonstrates that, whereas both healthy older controls and patients with a higher-level gait disorder walk more slowly in reduced lighting, only the latter's stride variability increases. Studies of the effects of dual tasks suggest that the regulation of the stride-to-stride fluctuations in stride width and stride time may be influenced by attention loading and may require cognitive input. Finally, a report of gait variability in over 500 subjects, probably the largest study of this kind, suggests how step width variability may relate to fall risk. Together, these studies provide new insights into the factors that regulate the stride-to-stride fluctuations in walking and pave the way for expanded research into the control of gait and the practical application of measures of gait variability in the clinical setting

Mejoras y valoración tras un programa de ejercicio específico para adultos mayores crónicos/paliativos

After analysing the impact of a cognitively oriented multicomponent home-based exercise training program on independence, perceived health status, and lower limb strength in a group of multimorbid and/or palliative older patients (MPO-P), we studied the associations between improvements following training and the participants and health personnel’s opinion of the program. 13 MPO-P, (80.15+4.20 years) completed four months of training progressing in autonomy (from two supervised sessions and one autonomous weekly -60min session-, to two autonomous and one supervised). This was followed by fourautonomous (detraining) weeks with a recommendation to continue the exercises. Volume and intensity were increased by introducing more global exercises, with a greater neuromuscular load and double tasks, and a shorter resting interval. No exercise was repeated during the session (EFAM-UV©). Independence (Barthel) and perceived health (physical SF-36, with no changes in the mental domain), were improved after supervised training, with a tendency to improve in strength (sitting and standing for 30-s) and perceived health (total SF-36). This effect was maintained after the autonomous detraining phase, with a very favourable final perception by both patients and health personnel, as indicated in questionnaires. The gain in independence correlated negatively with the users’perception, but this requirement ensured the improvement. There was no association between perceived health and the evaluation of the program.Tras analizar el impacto de un programa de entrenamiento domiciliario multicomponente, con orientación cognitiva, sobre independencia, percepción subjetiva de salud, y fuerza del miembro inferior en un grupo de adultos mayores crónicos multimórbidos y/o paliativos (MCM-Ps), se estudiaron las asociaciones entre las mejoras obtenidas y la valoración del programa de participantes y personal sanitario. 13 MCM-Ps (80.15+4.20 años) completaron cuatro meses de entrenamiento progresando en autonomía (de dos sesiones supervisadas y una autónoma semanalmente -60 min/sesión-, a dos autónomas y una supervisada). Le siguieron cuatro semanas autónomas (desentrenamiento) con recomendación de ejercicio. El volumen y la intensidad se aumentaron introduciendo más ejercicios integrales, con mayor carga neuromuscular y doble tarea, y menor tiempo de descanso entre ellos, sin repetirlos en la sesión (EFAM-UV©). Independencia (Barthel) y salud percibida (SF-36 físico, sin cambios en dominio mental) mejoraron tras el entrenamiento supervisado, con tendencia a la mejora de fuerza (sentarse y levantarse 30-s) y la salud percibida (SF-36total). El efecto permaneció tras la fase autónoma/desentrenamiento, con una percepción final muy favorable de pacientes y personal sanitario-determinada mediante cuestionarios-. La ganancia en independencia correlacionó negativamente con la valoración del usuario, pero esta exigencia aseguró su mejora. No hubo asociación entre salud percibida y valoración del programa.The study was financed by Vali+D Grant Nº ACIF/2014/137)

GPS analysis of a team competing at a national Under 18 field hockey tournament

The purpose of this study was to utilise global-positioning system (GPS) technology to quantify the running demands of national Under 18 field hockey players competing in a regional field hockey tournament. Ten male players (mean ± SD; age 17.2 ± 0.4 years; stature 178.1 ± 5.2 cm; body mass 78.8 ± 8.8 kg) wore GPS units while competing in six matches over seven days at the 2018 New Zealand national under 18 field hockey tournament. GPS enabled the measurement of total distance (TD), low-speed activity (LSA; 0 -14.9 km/hr), and high-speed running (HSR; ≥ 15 km/hr) distances. Differences in running demands (TD, LSA, HSR) between positions were assessed using effect size and percent difference ± 90% confidence intervals. Midfielders covered the most TD and LSA per game and strikers the most HSR during the 6 matches. There were “very large” differences between strikers and midfielders for TD and LSA, strikers and defenders for LSA and HSR, and defenders and midfielders for LSA. These results suggest that these playing positions are sufficiently different to warrant specialised position-specific conditioning training leading into a field hockey tournament