Effect of speed on local dynamic stability of locomotion under different task constraints in running

Abstract

A number of studies have investigated effects of speed on local dynamic stability of walking, although this relationship has been rarely investigated under changing task constraints, such as during forward and backward running. To rectify this gap in the literature, the aim of this study was to investigate the effect of running speed on local dynamic stability of forward and backward running on a treadmill. Fifteen healthy male participants took part in this study. Participants ran in forward and backward directions at speeds of 80%, 100% and 120% of their preferred running speed. The three-dimensional motion of a C7 marker was recorded using a motion capture system. Local dynamic stability of the marker was quantified using short- and long-term largest finite-time Lyapunov exponents (LyE). Results showed that short-term largest finite-time LyE values increased with participant speed meaning that local dynamic stability decreased with increasing speed. Long-term largest finite-time LyEs, however, remained unaffected as speed increased. Results of this study indicated that, as in walking, slow running is more stable than fast running. These findings improve understanding of how stability is regulated when constraints on the speed of movements is altered. Implications for the design of rehabilitation or sport practice programmes suggest how task constraints could be manipulated to facilitate adaptations in locomotion stability during athletic training.

Complexity, symmetry and variability of forward and backward walking at different speeds and transfer effects on forward walking: Implications for neural control

“…This finding may indicate that although the control required for BW is different to FW, both have a similar response to increased speed. Previous findings in backward and forward running have found that dynamic stability decreases with increasing speed similarly in both directions (Mehdizadeh et al, 2014). During FW, activity of the prefrontal cortex is increased with increasing walking speed (Hamacher et al, 2015;Harada et al, 2009;Suzuki et al, 2004).…”

“…multiscale entropy (MSE), changes across the lifespan with the development of the gait pattern (Bisi and Stagni, 2016). Recent studies have demonstrated that BW has similar long-range autocorrelations of stride intervals compared to FW (Bollens et al, 2014), or greater long-range autocorrelations suggesting the stride interval is more predictable in BW than FW (Dierick et al, 2017), and that increasing speed decreases local dynamic stability of trunk motion of backwards running (Mehdizadeh et al, 2014). Non-linear analyses provide insight into the neural control dynamics of locomotion (Bruijn et al, 2009;Costa et al, 2003;Dierick et al, 2017;Dingwell and Cusumano, 2010).…”

Linear and non-linear analysis of lower limb joints angle variability during running at different speeds

“…More recently, Kibushi et al (2018) revealed that LDS decreases while walking speed accelerates. Regarding the running performance, Mehdizadeh et al (2014) reported lower LDSs while the running speeds increase, either in forward or in the backward running. Besides, it has been highlighted that either increment or decrement of walking speed results in increased nonlinear variability in lower limb joint range of motion (Kang & Dingwell, 2008).…”

Evaluation of energy expenditure in forward and backward movements performed by soccer referees

“…All of these factors, and the fluctuation between them, influence the distribution of effort between the aerobic and anaerobic components, hampering the measurement of total energy consumption. However, the increase in speed promotes a reduction in body stability in a similar manner in both types of motor action, which explains the decrease of the difference in energy consumption with increasing intensity (speed) ( 28 ). In other words, with the increase in speed, and concomitant increased demand of the anaerobic system, there is a reduction in the consumption of oxygen.…”