Université de Fribourg

No evidence that frontal optical flow affects perceived locomotor speed and locomotor biomechanics when running on a treadmill

Caramenti, Martina ; Lafortuna, Claudio L. ; Mugellini, Elena ; Khaled, Omar Abou ; Bresciani, Jean-Pierre ; Dubois, Amandine

In: Applied Sciences, 2019, vol. 9, no. 21, p. 4589

We investigated how the presentation and the manipulation of an optical flow while running on a treadmill affect perceived locomotor speed (Experiment 1) and gait parameters (Experiment 2). In Experiment 1, 12 healthy participants were instructed to run at an imposed speed and to focus on their sensorimotor sensations to be able to reproduce this running speed later. After a pause, they had...

Université de Fribourg

Regular physical activity modulates perceived visual speed when running in treadmill-mediated virtual environments

Caramenti, Martina ; Lafortuna, Claudio L. ; Mugellini, Elena ; Khaled, Omar Abou ; Bresciani, Jean-Pierre ; Dubois, Amandine

In: PLOS ONE, 2019, vol. 14, no. 6, p. e0219017

In virtual reality, visual speed is usually underestimated relative to locomotor speed. Here we investigated how physical activity and fitness affect perceived visual speed when running in a treadmill-mediated virtual environment. Thirty healthy participants (ten sedentary individuals, ten team sport players and ten expert runners) ran on a treadmill at two different speeds (8, 12km/h) in...

Université de Fribourg

Fast and automatic assessment of fall risk by coupling machine learning algorithms with a depth camera to monitor simple balance tasks

Dubois, Amandine ; Mouthon, Audrey ; Sivagnanaselvam, Ranjith Steve ; Bresciani, Jean-Pierre

In: Journal of NeuroEngineering and Rehabilitation, 2019, vol. 16, no. 1, p. 71

Falls in the elderly constitute a major health issue associated to population ageing. Current clinical tests evaluating fall risk mostly consist in assessing balance abilities. The devices used for these tests can be expensive or inconvenient to set up. We investigated whether, how and to which extent fall risk could be assessed using a low cost ambient sensor to monitor balance tasks.Method:...

Université de Fribourg

Matching optical flow to motor speed in virtual reality while running on a treadmill

Caramenti, Martina ; Lafortuna, Claudio L. ; Mugellini, Elena ; Abou Khaled, Omar ; Bresciani, Jean-Pierre ; Dubois, Amandine

In: PLOS ONE, 2018, vol. 13, no. 4, p. e0195781

We investigated how visual and kinaesthetic/efferent information is integrated for speed perception in running. Twelve moderately trained to trained subjects ran on a treadmill at three different speeds (8, 10, 12 km/h) in front of a moving virtual scene. They were asked to match the visual speed of the scene to their running speed–i.e., treadmill’s speed. For each trial, participants...

Université de Fribourg

Validation of an ambient system for the measurement of gait parameters

Dubois, Amandine ; Bresciani, Jean-Pierre

In: Journal of Biomechanics, 2018, vol. 69, p. 175–180

Fall risk in elderly people is usually assessed using clinical tests. These tests consist in a subjective evaluation of gait performed by healthcare professionals, most of the time shortly after the first fall occurrence. We propose to complement this one-time, subjective evaluation, by a more quantitative analysis of the gait pattern using a Microsoft Kinect. To evaluate the potential of the...

Université de Fribourg

Automating the timed up and go test using a depth camera

Dubois, Amandine ; Bihl, Titus ; Bresciani, Jean-Pierre

In: Sensors, 2017, vol. 18, no. 1, p. 14

Fall prevention is a human, economic and social issue. The Timed Up and Go (TUG) test is widely used to identify individuals with a high fall risk. However, this test has been criticized because its “diagnostic” is too dependent on the conditions in which it is performed and on the healthcare professionals running it. We used the Microsoft Kinect ambient sensor to automate this test in...