Modulating Pendular Mechanics to Explore Whole-Body Energy Minimization During Walking

Introduction: During level walking, humans adopt gait patterns that minimize the net energy cost of walking (NCw). Metabolic energy is required by muscles to generate force and perform total positive mechanical work (Wtot). A component of Wtot is the external mechanical work (Wext), which represents the work performed to lift and accelerate the body’s center of mass (CoM). The pendular exchange of potential and kinetic energy (Rstep) during the walk reduces Wext, thereby minimizing NCw (Peyré-Tartaruga et al., 2021). Altered Rstep has been associated with a higher NCw in older and obese adults (Fernández Menéndez et al., 2020; Malatesta et al., 2003). Older adults exhibit lower Rstep (Nùñez-Lisboa & Dewolf, 2025), whereas adults with obesity display higher Rstep and lower Wext (Fernández Menéndez et al., 2020), suggesting an adaptive mechanism that mitigates the increase in NCw in this population (Fernández Menéndez et al., 2020). Therefore, this study aimed to examine the effects of modulating the pendular mechanism via a real-time visual biofeedback on the energetics and mechanics of walking in healthy individuals. Method: 15 healthy adults (7 men and 8 women; height: 1.73±0.10 meters; body mass: 70.9±13.1 kg; age: 26.2±4.3 yr) walked 5 min at 4 km/h on an instrumented treadmill (Gaitway-3D, ®Arsalis, Belgium) in 3 different experimental conditions: 1) normal walking to assess the preferred Rstep values (0%) and at 2) -10% and 3) +10% of preferred Rstep values using a real-time visual biofeedback during the 5 min to obtain these targeted values. Gas exchanges were collected to assess the NCw (J·kg-1·m-1). The ground reaction forces were measured to generate real-time visual biofeedback during -10% and +10% Rstep trials and to assess walking mechanics (Wext and Rstep) during 30 seconds of each walking trial (Fernández Menéndez et al., 2020). Locomotor efficiency was calculated as Wext divided by the NCw (Griffin et al., 2003). Result: NCw increased significantly at +10% (p=0.010) and -10% (p