Control of impact loading during distracted running before and after gait retraining in runners

2017 ◽  
Vol 36 (13) ◽  
pp. 1497-1501 ◽  
Author(s):  
Roy T. H. Cheung ◽  
Winko W. An ◽  
Ivan P. H. Au ◽  
Janet H. Zhang ◽  
Zoe Y. S. Chan ◽  
...  
2018 ◽  
Vol 39 (14) ◽  
pp. 1075-1080 ◽  
Author(s):  
Eric Ching ◽  
Winko An ◽  
Ivan Au ◽  
Janet Zhang ◽  
Zoe Chan ◽  
...  

AbstractVisual feedback gait retraining has been reported to successfully reduce impact loading in runners, even when the runners were distracted. However, auditory feedback is more feasible in real life application. Hence, this study compared the peak positive acceleration (PPA), vertical average (VALR) and instantaneous (VILR) loading rate during distracted running before and after a course of auditory feedback gait retraining in 16 runners. The runners were asked to land with softer footfalls with and without auditory feedback. Low or high sound pitch was generated according to the impact of particular footfall, when compared with the preset target. Runners then received a course of auditory gait retraining, and after the gait retraining, runners completed a reassessment. Runners before gait retraining exhibited lower PPA, VALR and VILR with augmented auditory feedback (p<0.049). We found a reduction in PPA, VALR and VILR after gait retraining, regardless of the presence of feedback (p<0.018). However, runners after gait retraining did not demonstrate further reduction in PPA and VALR with auditory feedback (p>0.104). A small effect of auditory feedback on VILR in runners after gait retraining was observed (p=0.032). Real time auditory feedback gait retraining is effective in impact loading reduction, even when the runners were distracted.


2010 ◽  
Vol 452-453 ◽  
pp. 481-484
Author(s):  
Yi Ping Liu ◽  
Ting Hui He ◽  
Li Qun Tang ◽  
Xiao Qing Huang

In this paper coupling damage behaviors of Liquid Rubber Based Concrete (LRBC) are studied experimentally. Compressive fatigue and impact alternant loading tests were carried out on cylindrical LRBC specimens. The elastic moduli were recorded before and after fatigue and impact tests. The quasi-static compressive stress-strain curves after fatigue and impact tests were obtained. According to the definition of dissipated energy, the cumulating of dissipated energy was used to define damage. The analysis on impact and fatigue damages during the loading processes show that fatigue and impact loading lead to the formation and development of inner damage. During the alternant loading process, impact and fatigue damages are coupled mutually, with the former affects the evolution of fatigue damage evidently.


2016 ◽  
Vol 48 ◽  
pp. 495
Author(s):  
Ivan P.H. Au ◽  
Winko W. An ◽  
K.H. Ting ◽  
Irene S. Davis ◽  
Roy T.H. Cheung

2020 ◽  
Vol 42 ◽  
pp. 139-145 ◽  
Author(s):  
Zoe Y.S. Chan ◽  
Janet H. Zhang ◽  
Reed Ferber ◽  
Gary Shum ◽  
Roy T.H. Cheung

2019 ◽  
pp. 1-16 ◽  
Author(s):  
Rachel X. Wei ◽  
Ivan P. H. Au ◽  
Fannie O. Y. Lau ◽  
Janet H. Zhang ◽  
Zoe Y. S. Chan ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Andrzej Komorek ◽  
Paweł Przybyłek ◽  
Wojciech Kucharczyk

This paper reports the results of the effect of sea water, natural ageing, and cross-impact loading on flexural strength and residual flexural strength of epoxy laminates with glass woven fabrics and hybrid reinforcement with glass and carbon woven fabrics. The tests were conducted on samples with different fibre reinforcement both before and after low energy cross-impact loading. Carbon fabrics decreased residual strength of the composites.


2022 ◽  
Vol 92 (2) ◽  
pp. 279
Author(s):  
И.П. Щербаков ◽  
А.Е. Чмель

The mechanical fracture of silicon dioxide initiates the mechanoluminescence (ML) lighting due to multiple breakage of interatomic bonds with producing non-bridged oxygen groups of [Si–O–]. The detected ML signals consisted of series of pulses, the energy of which is proportional to the number of photons irradiated from the broken bonds. The comparative analysis of the energy distributions in ML series induced by the impact damage of the surface of crystalline and vitreous SiO2 before and after the Ar+-ion implantation was conducted. The interplay between random and correlated accumulation of broken bonds under the impact loading was found and discussed.


2009 ◽  
Vol 30 ◽  
pp. S4-S5 ◽  
Author(s):  
I.S. Davis ◽  
H.P. Crowell ◽  
R.E. Fellin ◽  
A.R. Altman

2019 ◽  
Vol 23 (3) ◽  
pp. 332-347
Author(s):  
Valerio Lorenzoni ◽  
Tijl De Bie ◽  
Thierry Marchant ◽  
Edith Van Dyck ◽  
Marc Leman

Running with musical accompaniment is becoming increasingly popular and several pieces of software have been developed that match the music tempo to the exerciser’s running cadence, that is, foot strikes per minute. Synchronizing music with running cadence has been shown to affect several aspects of performance output and perception. The purpose of this study was to investigate the effect of synchronous music on runners’ foot impact loading. This represents the ground reaction force on the runner’s lower leg when the foot impacts the ground and is an important parameter for the prevention of tibial fracture injuries. Twenty-eight participants ran five times for three minutes and 30 seconds with a short break between each run. During the first 30 seconds of each running sequence, participants ran at a self-paced tempo without musical accompaniment, and running speed and cadence were measured. Subsequently, they were requested to keep their reference speed constant for the following three minutes, with the help of three monitoring screens placed along the track. During this part of the experiment, the music was either absent ( No Music), matched to the runner’s cadence ( Tempo-entrained Sync), phase-locked with foot strikes ( Phase-locked Sync), or played at a tempo 30% slower ( Minus 30%) or faster ( Plus 30%) than the initially measured running cadence. No significant differences between synchronous and asynchronous music were retrieved for impact loading. However, a non-negligible average increase of impact level could be observed for running sessions with music compared to running in silence. These findings might be especially relevant for treatment purposes, such as exercise prescription and gait retraining, and should be taken into account when designing musical (re-)training programmes.


Author(s):  
J. Temple Black

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.


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