Characteristics of preferred gait patterns: considerations for exercise prescription

Gait patterns have been widely studied in different fields of science for their particular characteristics. A dynamic approach of human locomotion considers walking and running as two stable behaviors adopted spontaneously under certain levels and natures of constraints. When no constraints are imposed, people naturally prefer to walk at the typical speed (i.e., around 4.5 km.h-1) that minimizes metabolic energy cost. The preferred walking speed (PWS) is also known to be an indicator of mobility and an important clinical factor in tracking impairements in motor behaviors. When constrained to move at higher speeds (e.g., being late), people naturally switch their preference to running for similar optimization reasons (e.g., physiological, biomechanical, perceptual, attentionnal costs). Indeed, the preferred transition speed (PTS) marks the natural seperation between walking and running and consistently falls within a speed range around 7.5 km.h-1. This chapter describes the constraint-dependant spontaneous organisation of the locomotor system, specifically on the walk-to-run speed continuum. We provide examples of the possibility of long-term adaptations of preferred behaviors to specific constraints such as factors related to traditional clothing or practice. We use knowledge from studies on preferred behaviors and on the relationship between affect and exercise adherence as a backdrop to prescribing a walk exercise program with an emphasis on populations with overweight or obesity.

Towards a smart semi-active prosthetic leg: preliminary assessment and testing

This paper presents a development of a semi-active prosthetic knee, which can work in both active and passive modes based on the energy required during the gait cycle of various activities of daily livings (ADLs). The prosthetic limb is equipped with various sensors to measure the kinematic and kinetic parameters of both prosthetic limbs. This prosthetic knee is designed to be back-drivable in passive mode to provide a potential use in energy regeneration when there negative energy across the knee joint. Preliminary test has been performed on transfemoral amputee in passive mode to provide some insight to the amputee/prosthesis interaction and performance with the designed prosthetic knee.