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Effect of speed on the weight transfer between legs during gait in elderly people
Gait & Posture 49S (2016) 46
Contents lists available at ScienceDirect
Gait & Posture journal homepage: www.elsevier.com/locate/gaitpost
O38 presented in OS06: Healthy walking
Effect of speed on the weight transfer between legs during gait in elderly people Guillaume M. Meurisse 1,*, Guillaume J. Bastien 1,2, Be´ne´dicte Schepens 1 1 2
Laboratoire de Physiologie et Biome´canique de la Locomotion, Institute of NeuroScience, Universite´ Catholique de Louvain, Louvain-la-Neuve, Belgium Arsalis SPRL, Glabais, Belgium
Introduction: Falling is the most frequent reason of unintentional injuries in our ageing population. Falls happen mainly when the elderly are walking forward and during the body weight transfer between supports [1]. Therefore, investigation about the body weight shift from the back leg to the front leg during gait in elderly is necessary. When walking, the gait weight transfer (gWT) changes with speed. So we investigated the evolution of the gWT with age by comparing young and old adults walking at matched speed. In this way, we can isolate the effect of age from the effect of speed. Research question: How does the weight transfer evolve with age when walking at matched speeds?
Materials and methods: Eight young (21–28 y) and seventeen elderly (65–70 y, n = 6; 70–75 y, n = 5; >75 y, n = 6) healthy subjects without history of falling were enrolled. Subjects were asked to walk on an instrumented treadmill at 5 different selected speeds from 0.56 to 1.67 m s 1. An algorithm was used to determine the vertical ground reaction forces (GRFv) acting upon each limb during gWT [2]. The following parameters were calculated in order to characterized the dynamics around the gWT: the stride and gWT durations, the maximum GRFv exerted by the back leg (maxBACK, in black) and exerted by the front leg (maxFRONT, in grey) and the difference between the two (Dmax, normalized in body weight).
Result and discussion: Results show that, at a given speed, elderly subjects have a shorter stride and gWT durations, as well as a greater Dmax in comparison to young subjects. In young adults, both maxBACK and maxFRONT increase fairly equally with increasing speed, so Dmax remains fairly constant except at high speeds. In elderly subjects, the effect of speed on gWT is more pronounced: maxBACK remains constant while maxFRONT increases substantially with speed, leading to a Dmax as high as half the body weight at high speed (see figure). These baseline observations on non-falling subjects indicate that gWT is modified during aging with a higher impact on the
front leg and a supporting force on the back that did not increase with speed. These results could allow detection of ‘‘outliers’’ patterns of gait or provide clues to explain falls.
* Corresponding author. E-mail address: [email protected] (G.M. Meurisse). http://dx.doi.org/10.1016/j.gaitpost.2016.07.110 0966-6362/
References [1] Robinovitch. et al. Lancet 2013;381:47–54. [2] Meurisse. et al. Gait Posture 2016;43:245–50.
Contents lists available at ScienceDirect
Gait & Posture journal homepage: www.elsevier.com/locate/gaitpost
O38 presented in OS06: Healthy walking
Effect of speed on the weight transfer between legs during gait in elderly people Guillaume M. Meurisse 1,*, Guillaume J. Bastien 1,2, Be´ne´dicte Schepens 1 1 2
Laboratoire de Physiologie et Biome´canique de la Locomotion, Institute of NeuroScience, Universite´ Catholique de Louvain, Louvain-la-Neuve, Belgium Arsalis SPRL, Glabais, Belgium
Introduction: Falling is the most frequent reason of unintentional injuries in our ageing population. Falls happen mainly when the elderly are walking forward and during the body weight transfer between supports [1]. Therefore, investigation about the body weight shift from the back leg to the front leg during gait in elderly is necessary. When walking, the gait weight transfer (gWT) changes with speed. So we investigated the evolution of the gWT with age by comparing young and old adults walking at matched speed. In this way, we can isolate the effect of age from the effect of speed. Research question: How does the weight transfer evolve with age when walking at matched speeds?
Materials and methods: Eight young (21–28 y) and seventeen elderly (65–70 y, n = 6; 70–75 y, n = 5; >75 y, n = 6) healthy subjects without history of falling were enrolled. Subjects were asked to walk on an instrumented treadmill at 5 different selected speeds from 0.56 to 1.67 m s 1. An algorithm was used to determine the vertical ground reaction forces (GRFv) acting upon each limb during gWT [2]. The following parameters were calculated in order to characterized the dynamics around the gWT: the stride and gWT durations, the maximum GRFv exerted by the back leg (maxBACK, in black) and exerted by the front leg (maxFRONT, in grey) and the difference between the two (Dmax, normalized in body weight).
Result and discussion: Results show that, at a given speed, elderly subjects have a shorter stride and gWT durations, as well as a greater Dmax in comparison to young subjects. In young adults, both maxBACK and maxFRONT increase fairly equally with increasing speed, so Dmax remains fairly constant except at high speeds. In elderly subjects, the effect of speed on gWT is more pronounced: maxBACK remains constant while maxFRONT increases substantially with speed, leading to a Dmax as high as half the body weight at high speed (see figure). These baseline observations on non-falling subjects indicate that gWT is modified during aging with a higher impact on the
front leg and a supporting force on the back that did not increase with speed. These results could allow detection of ‘‘outliers’’ patterns of gait or provide clues to explain falls.
* Corresponding author. E-mail address: [email protected] (G.M. Meurisse). http://dx.doi.org/10.1016/j.gaitpost.2016.07.110 0966-6362/
References [1] Robinovitch. et al. Lancet 2013;381:47–54. [2] Meurisse. et al. Gait Posture 2016;43:245–50.