Estimation of tibial and femoral 3D linear accelerations during gait

Abstract

Shock wave traveling through the skeletal are more and more considered in the development of articular disorders. A method to quantify those skeletal transients is to estimate body segment linear accelerations. However, linear accelerations magnitude is influenced by many factors such as location and fixation of sensors, walking velocity, walking level and also by wearing conditions. Hence, experimental results in literature can't be easily compared and normative data haven't been established yet. The present paper proposes a method to estimate three-dimensional (3D) tibial and femoral linear accelerations during treadmill walking. 15 able-bodied subjects were evaluated. 3D kinematics data recorded from an optoelectronic system (Optotrak 3010, Northern Digital, Canada) at knee joint level were derived to estimated 3D linear accelerations of the tibia and the femur at their respective coordinate system origins.

Developmental Dyscalculia and Automatic Magnitudes Processing: Investigating Interference Effects between Area and Perimeter

“…In the past few years, the relationship between numbers and other magnitudes, such as space and time, has evoked a great deal of interest ( Walsh, 2003 ; Dehaene and Brannon, 2010 ; Gebuis and Reynvoet, 2012a ; Newcombe, 2014 ; Leibovich et al, 2016 ; McCaskey et al, 2017 ). Walsh (2003) was the first to suggest the existence of a common processing mechanism for time, space, and quantity, and he established a Theory of Magnitude (ATOM).…”

“…Specifically, recent research implies the existence of a magnitude estimation mechanism representing both numerical and other continuous magnitudes, including area, perimeter, length, volume, time, etc. ( Lourenco and Longo, 2010 ; Dakin et al, 2011 ; Gebuis and Reynvoet, 2012b ; Leibovich and Henik, 2013 , 2014 ; Newcombe, 2014 ; Leibovich et al, 2016 ; Lourenco and Bonny, 2016 ).…”

“…To this end, it is not clear whether one magnitude (area) can be more perceptually salient than the other (perimeter). According to general magnitude mechanism theories, both magnitudes should be involuntarily processed and hence are supposed to interfere with each other to a similar degree ( Newcombe, 2014 ; Leibovich et al, 2016 ). On the other hand one magnitude, in this case area (as found in Babai et al, 2006 ), can interfere with the processing of another magnitude (perimeter), but not vice versa.…”

“…The discussion of a general magnitude processing mechanism as a basis for numerical cognition development seems to be more relevant than ever ( Gebuis and Reynvoet, 2012b ; Leibovich and Henik, 2014 ; Newcombe, 2014 ; Lourenco and Bonny, 2016 ; Leibovich et al, 2016 ). However, there exists no extensive work dealing with intact and deficient processing of this system ( Skagerlund and Träff, 2014 ; McCaskey et al, 2017 ).…”

“…We expected to find group differences, as measured by Stoop effects (incongruent minus congruent trials) in both area and perimeter comparison tasks. According to domain-specific magnitude processing deficits ( Newcombe, 2014 ; Leibovich et al, 2016 ), the DD group is expected to show smaller Stroop effects implying that they do not process the irrelevant magnitude (similar to the numerical Stroop task, Rubinsten and Henik, 2005 ). On the other hand, domain-general deficits ( Wang et al, 2012 ; Szucs et al, 2013a ; Bugden and Ansari, 2015 ) should result in larger Stroop effects in the DD group, due to a deficit in the ability to ignore irrelevant magnitude information.…”