This study involved a comparison of 5 kinematic-based algorithms to detect heel strike (HS) and toe-off (TO) events during human locomotion at different speeds. The objective was to assess how different running and walking speeds affect contact event determination during treadmill locomotion. Thirty male runners performed walking at 5 km/h and running at 9, 11, and 13 km/h on a treadmill. A kinematic system was used to capture the trajectories of 2 retro-reflective markers placed at the subject’s right heel and second metatarsal. A footswitch device was used to determine the “true” times of HS and TO compared with 5 kinematic-based algorithms. The results of the current study illustrated that speed influences the HS error in the vertical position and horizontal velocity algorithms, and the TO error in the vertical position and horizontal velocity algorithms. This difference was found in the transition from walking to running; however, higher running speeds did not affect the error estimation. Higher accuracy was found with combined algorithms, namely, one using vertical acceleration and position and another using horizontal and vertical position with no influence from different locomotion speeds. Therefore, these algorithms are recommended in studies where speed is self-selected because they work well for a broad range of locomotion velocities.
Felipe Alvim, Lucenildo Cerqueira, Aluízio D’Affonsêca Netto, Guilherme Leite and Adriane Muniz
Kirsten Tulchin, Michael Orendurff, Stephen Adolfsen and Lori Karol
Multisegment foot models provide researchers more-detailed information regarding foot mechanics compared with single rigid body foot models. Previous work has shown that walking speed significantly affects sagittal plane ankle motion. It is important to distinguish changes in intersegment foot mechanics following treatment that are due to clinical intervention versus those due to walking speed alone. Foot and ankle kinematics were collected on 24 adults walking at 5 speeds. Significant differences were seen at the ankle using a single rigid body foot model, as well as at the hindfoot and forefoot using a multisegment foot model, with all motions exhibiting a shift toward plantar flexion and decreased stance time with increasing speed. When evaluating foot mechanics using a multisegment foot model across groups or conducting intrasubject comparison over time/treatments, it is imperative that walking speed be accounted for or controlled.
Christopher A. Zirker, Bradford C. Bennett and Mark F. Abel
We examined how the application of a forward horizontal force applied at the waist alters the metabolic cost, kinematics, and external work of gait. Horizontal assist forces of 4%, 8% and 12% of a subject’s body weight were applied via our testing apparatus while subjects walked at comfortable walking speed on a level treadmill. Kinematic and metabolic parameters were measured using motion capture and ergospirometry respectively on a group of 10 healthy male subjects. Changes in kinematic and metabolic parameters were quantified and found similar to walking downhill at varying grades. A horizontal assist force of 8% resulted in the greatest reduction of metabolic cost. Changes in recovery factor, external work, and center of mass (COM) movement did not correlate with changes in metabolic rate and therefore were not driving the observed reductions in cost. The assist force may have performed external work by providing propulsion as well as raising the COM as it pivots over the stance leg. Assist forces may decrease metabolic cost by reducing the concentric work required for propulsion while increasing the eccentric work of braking. These findings on the effects of assist forces suggest novel mobility aids for individuals with gait disorders and training strategies for athletes.
Mark Elisabeth Theodorus Willems, Mehmet Akif Şahin and Matthew David Cook
Intake of the catechin epigallocatechin gallate and caffeine has been shown to enhance exercise-induced fat oxidation. Matcha green tea powder contains catechins and caffeine and is consumed as a drink. We examined the effect of Matcha green tea drinks on metabolic, physiological, and perceived intensity responses during brisk walking. A total of 13 females (age: 27 ± 8 years, body mass: 65 ± 7 kg, height: 166 ± 6 cm) volunteered to participate in the study. Resting metabolic equivalent (1-MET) was measured using Douglas bags (1-MET: 3.4 ± 0.3 ml·kg−1·min−1). Participants completed an incremental walking protocol to establish the relationship between walking speed and oxygen uptake and individualize the walking speed at 5- or 6-MET. A randomized, crossover design was used with participants tested between Days 9 and 11 of the menstrual cycle (follicular phase). Participants consumed three drinks (each drink made with 1 g of Matcha premium grade; OMGTea Ltd., Brighton, UK) the day before and one drink 2 hr before the 30-min walk at 5- (n = 10) or 6-MET (walking speed: 5.8 ± 0.4 km/hr) with responses measured at 8–10, 18–20, and 28–30 min. Matcha had no effect on physiological and perceived intensity responses. Matcha resulted in lower respiratory exchange ratio (control: 0.84 ± 0.04; Matcha: 0.82 ± 0.04; p < .01) and enhanced fat oxidation during a 30-min brisk walk (control: 0.31 ± 0.10; Matcha: 0.35 ± 0.11 g/min; p < .01). Matcha green tea drinking can enhance exercise-induced fat oxidation in females. However, when regular brisk walking with 30-min bouts is being undertaken as part of a weight loss program, the metabolic effects of Matcha should not be overstated.
Anna M. Ifarraguerri, Danielle M. Torp, Abbey C. Thomas and Luke Donovan
treadmill walking by reducing the lateral plantar pressure of their injured limb in response to receiving real-time video feedback. We hypothesized that, in response to real-time video feedback, participants with CAI would be able to decrease peak pressure and pressure-time integral on the lateral aspect of
Yoav Gimmon, Hisham Rashad, Ilan Kurz, Meir Plotnik, Raziel Riemer, Ronen Debi, Amir Shapiro and Itshak Melzer
hands free to swing; there were no handrails on the treadmill. Familiarization with the treadmill was achieved for each subject by 4–7 min of walking prior to data collection. To prevent injury if loss of balance occurred during the treadmill walking, the subject wore a loose safety harness that could
Mhairi J. MacDonald, Samantha G. Fawkner, Ailsa G. Niven and David Rowe
, difficult to accurately extrapolate step rate corresponding to moderate and moderate- to vigorous-intensity walking, due to the different intensity markers used and lack of direct assessment of energy expenditure. A major limitation with several of these studies is the assumption that treadmill walking is
Mustafa M.O. Elhadi, Christina Z. Ma, Duo W.C. Wong, Anson H.P. Wan and Winson C.C. Lee
treadmill walking at any time they requested. Gait analysis and subjective assessments were conducted (1) before treadmill walking, (2) after the first 30-min session of treadmill walking, and 3) after the second 30-min session of treadmill walking. Subjects walked in self-selected comfortable speed in both
Alexander H.K. Montoye, Jordana Dahmen, Nigel Campbell and Christopher P. Connolly
alternate body location. In a previous study, Connolly et al. ( 2011 ) examined accuracy of four hip-worn PA monitors (3 pedometers, 1 accelerometer) for step counting during treadmill walking in second and third trimester pregnant women, finding that only two of the devices (both pedometers: New Lifestyle
Scott W. Ducharme and Richard E.A. van Emmerik
clear consensus has not been agreed upon. Finally, treadmill versus overground walking may produce differences in scaling exponents, as treadmill walking generally reduces the scaling exponent ( Terrier & Deriaz, 2011 ). In addition to preferred speed walking conditions, long-range correlations in young