LANDING PATTERN AND VERTICAL LOADING RATES DURING SHOD AND BAREFOOT RUNNING IN HABITUAL SHOD RUNNERS

There is evidence to support that habitual barefoot runners are able to disperse impact loading rates by landing pattern modification. However, case studies have been reported that barefoot running may cause stress fractures. It may be due to the immediate biomechanical response difference between habitual and novice barefoot runners. Therefore, purpose of this study was to examine the immediate effects of barefoot running in habitual shod runners. Thirty habitual shod runners were asked to run on an instrumented treadmill at 10km/hr in shod and barefoot. Vertical average (VALR) and instantaneous loading rates (VILR) were obtained by previously established methods. The landing pattern was presented as a ratio between number of footfall with heel-strike and the total step number. Twenty out of 30 participants demonstrated an automatic transition to a non-heel-strike landing. A mixed landing pattern was observed in 10 participants. Compared to shod running, both VALR and VILR significantly reduced during barefoot running (

Editorial: COVID-19 pandemic:A curve ball for athletes

More than 30 months since the discovery of the novel respiratory coronavirus in 2019, COVID-19 related public health orders and restrictions remain active in many countries on the globe in late 2022. These measures, such as city lockdown, border closure, travel restrictions, social distancing practice, and mandatory use of facemasks, affect all segments of the population. During the pandemic, we have witnessed the most significant disruption to the worldwide sports calendar since the World War II. From a global perspective, many international sports events, such as The Olympic Games Tokyo 2020, SummerWorld University Games, and theWorld Games have been postponed; and more than 150 international sports events involving both professional and recreational sportsmen have been canceled. In this series, we cover original articles examining the effect of COVID-19 on the training routine and performance in five types of athletes, including distance runners (Chan et al.), soccer/football players (Wagemans et al.; Keemss et al.), bodybuilders (Imboden et al.; Iff et al.), volleyball players (Morath et al.), and paralympic athletes (Busch et al.). We are aware that this field of research is highly dynamic with new data available almost on a daily base. Hence, we aim to bemore inclusive in this Research Topic and involve a wider scope of research questions and different methodological approaches, which allow us a better coverage of this emerging and evolving Research Topic. These findings provide important information for athletes, coaches, physical trainers, and healthcare team members to identify potential health issues that may be related to the pandemic, plan specifically how we can minimize the negative influence, as well as design contingency training plan for postponed tournaments. Although COVID-19 attacks our respiratory system and potentially causes a decline in physical condition, we observed adverse findings from the studies in this Research Topic in terms of physical training. Iff et al. and Keemss et al. reported a pandemic related negative impact on the physical performance in body builders and youth soccer players, respectively. In contrast, Chan et al. and Wagemans et al. did not find any substantial differences in terms of physical function or training intensity in professional soccer players and recreational distance runners. Interestingly, it seems that COVID-19 and its related public health restrictions result in a greater influence on people’s mental than physical health. For example, Imboden et al., Busch et al., and Iff et al. reported that athletes exhibited poorer mood during the pandemic and this psychological impact may indeed lead to a change in living habits, such as increase alcoholic and cannabis intake. From a global perspective, this Research Topic also includes an investigation of COVID transmission within volleyball games. Morath et al. conducted contact tracing in a professional volleyball teamin Germany. They found that players who strictly adhere to the recommended hygiene guidelines and regulations during both training and matches are of lower risk contracting the virus, but coaches and players are advised to avoid nonessential interpersonal contacts outside the training hours to prevent the spread of infection. Although the guest editors would love to see more views, downloads, and citations of papers included in this series, we sincerely hope that athletes, coaches, and concerning healthcare professionals do not require the information presented in this Research Topic due to another wave of pandemic and disruption. May COVID-19 will be soon behind us and becomes a historical terminology in near future

A validation study of a smartphone application for functional mobility assessment of the elderly

AbstractBackgroundTo minimize the reaction time and position judgment error using stopwatch-timed measures, we developed a smartphone application to measure performance in the five-time sit-to-stand (FTSTS) and timed up-and-go (TUG) tests.ObjectiveThis study aimed to validate this smartphone application by comparing its measurement with a laboratory-based reference condition.MethodsThirty-two healthy elderly people were asked to perform the FTSTS and TUG tests in a randomized sequence. During the tests, their performance was concurrently measured by the smartphone application and a force sensor installed in the backrest of a chair. The intraclass correlation coefficient [ICC(2,1)] and Bland–Altman analysis were used to calculate the measurement consistency and agreement, respectively, between these two methods.ResultsThe smartphone application demonstrated excellent measurement consistency with the lab-based reference condition for the FTSTS test [ICC(2,1) = 0.988] and TUG test [ICC(2,1) = 0.946]. We observed a positive bias of 0.27 seconds (95% limits of agreement, −1.22 to 1.76 seconds) for the FTSTS test and 0.48 seconds (95% limits of agreement, −1.66 to 2.63 seconds) for the TUG test.ConclusionWe cross-validated the newly developed smartphone application with the laboratory-based reference condition during the examination of FTSTS and TUG test performance in healthy elderly

The Effects of Midfoot Strike Gait Retraining on Impact Loading and Joint Stiffness

Objective: To assess the biomechanical changes following a systematic gait retraining to modify footstrike patterns from rearfoot strike (RFS) to midfoot strike (MFS). Design: Pre-post interventional study. All participants underwent a gait retraining program designed to modify footstrike pattern to MFS. Setting: Research laboratory. Participants: Twenty habitual RFS male runners participated. Main Outcome Measures: Gait evaluations were conducted before and after the training. Footstrike pattern, loading rate (LR), ankle and knee joint stiffness were compared. Results: Participants’ footstrike angle was reduced (p<0.001, Cohen’s d=1.65) and knee joint stiffness was increased (p=0.003, Cohen’s d=0.69). No significant difference was found in the vertical loading rates (p>0.155). Further sub-group analyses were conducted on the respondents (n=8, 40% of participants) who exhibited MFS for over 80% of their footfalls during the post-training evaluation. Apart from the increased knee joint stiffness (p=0.005, Cohen’s d=1.14), respondents exhibited a significant reduction in the ankle joint stiffness (p=0.019, Cohen’s d=1.17) when running with MFS. Conclusions: Gait retraining to promote MFS was effective in reducing runners’ footstrike angle, but only 40% of participants responded to this training program. The inconsistent training effect on impact loading suggests a need to develop new training protocols in an effort to prevent running injuries

Difference in the running biomechanics between preschoolers and adults

Background: High vertical loading rate is associated with a variety of running-related musculoskeletal injuries. There is evidence supporting that non-rearfoot footstrike pattern, greater cadence, and shorter stride length may reduce the vertical loading rate. These features appear to be common among preschoolers, who seem to experience lower running injury incidence, leading to a debate whether adults should accordingly modify their running form. Objective: This study sought to compare the running biomechanics between preschoolers and adults. Methods: Ten preschoolers (4.2 ± 1.6 years) and ten adults (35.1 ± 9.5 years) were recruited Q3 and ran overground with their usual shoes at a self-selected speed. Vertical average (VALR) and vertical instantaneous loading rate (VILR) were calculated based on the kinetic data. Footstrike pattern and spatiotemporal parameters were collected using a motion capture system. Results: There was no difference in normalized VALR (p = 0.48), VILR (p = 0.48), running speed (p = 0.85), and footstrike pattern (p = 0.29) between the two groups. Preschoolers demonstrated greater cadence (p < 0.001) and shorter normalized stride length (p = 0.01). Conclusion: By comparing the kinetic and kinematic parameters between children and adults, our findings do not support the notion that adults should modify their running biomechanics according to the running characteristics in preschoolers for a lower injury risk. © 2020 Associac¸ao˜ Brasileira de Pesquisa e Pos-Graduac¸ ´ ao˜ em Fisioterapia. Published by Elsevier Editora Ltda. All rights reserved

Effects of deceptive footwear condition on subjective comfort and running biomechanics

Comfort is a major criterion for footwear selection. Previous studies have suggested that physical properties were not enough to predict comfort and psychological factors could also affect the perception. To understand comfort, this study examined the effect of controlled shoe description and price cue on the perception of comfort. Furthermore, this study also examined the running biomechanics in response to footwear conditions of differing comfort. Fifteen runners completed treadmill running tests in two conditions: Shoe A and Shoe B. The same pair of neutral running shoes was used in both conditions, yet, Shoe B was described to be the “latest model designed to maximize comfort” and more expensive than Shoe A. Comfort assessment was conducted after the running trial of each condition. Participants reported significantly greater comfort in Shoe B than Shoe A (p=0.011, Cohen’s d=0.70). There were no significant differences found among the temporal-spatial parameters (p>0.916) and the vertical loading rates (p>0.161) when comparing the more and less comfortable conditions. In conclusion, runners exhibited a biased perception of footwear comfort when presented with different shoe description and price information. However, such a difference in perceived comfort alone is not likely to affect running biomechanics

Gait Retraining for the Reduction of Injury Occurrence in Novice Distance Runners: 1-Year Follow-up of a Randomized Controlled Trial

Background: The increasing popularity of distance running has been accompanied by an increase in running-related injuries, such that up to 85% of novice runners incur an injury in a given year. Previous studies have used a gait retraining program to successfully lower impact loading, which has been associated with many running ailments. However, softer footfalls may not necessarily prevent running injury. Purpose: To examine vertical loading rates before and after a gait retraining program and assess the effectiveness of the program in reducing the occurrence of running-related injury across a 12-month observation period. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 320 novice runners from the local running club completed this study. All the participants underwent a baseline running biomechanics evaluation on an instrumented treadmill with their usual running shoes at 8 and 12 km/h. Participants were then randomly assigned to either the gait retraining group or the control group. In the gait retraining group (n = 166), participants received 2 weeks of gait retraining with real-time visual feedback. In the control group (n = 154), participants received treadmill running exercise but without visual feedback on their performance. The training time was identical between the 2 groups. Participants’ running mechanics were reassessed after the training, and their 12-month posttraining injury profiles were tracked by use of an online surveillance platform. Results: A significant reduction was found in the vertical loading rates at both testing speeds in the gait retraining group (P 0.99), whereas the loading rates were either similar or slightly increased in the control group after training (P = .001 to 0.461, Cohen’s d = 0.03 to −0.14). At 12-month follow-up, the occurrence of running-related musculoskeletal injury was 16% and 38% in the gait retraining and control groups, respectively. The hazard ratio between gait retraining and control groups was 0.38 (95% CI, 0.25-0.59), indicating a 62% lower injury risk in gait-retrained runners compared with controls. Conclusion: A 2-week gait retraining program is effective in lowering impact loading in novice runners. More important, the occurrence of injury is 62% lower after 2 weeks of running gait modification. Registration: HKUCTR-1996 (University of Hong Kong Clinical Trials Registry)

Impact loading during distracted running before and after auditory gait retraining.

Visual 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 (p0.104). 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

Effect of minimalist and maximalist shoes on impact loading and footstrike pattern in habitual rearfoot strike trail runners: an in-field study

Running-related injuries among trail runners are very common and footwear selection may modulate the injury risk. However, most previous studies were conducted in a laboratory environment. The objective of this study was to examine the effects of two contrasting footwear design, minimalist (MIN) and maximalist shoes (MAX), on the running biomechanics of trail runners during running on a natural trail. Eighteen habitual rearfoot strike trail runners completed level, uphill and downhill running at their preferred speeds in both shod conditions. Peak tibial acceleration, strike index and footstrike pattern were compared between the two footwear and slopes. Interactions of footwear and slope were not detected for all the selected variables. There was no significant effect from footwear (F=1.23, p=0.27) and slope (F=2.49, p=0.09) on peak tibial acceleration and there was no footwear effect on strike index (F=3.82, p=0.056). A significant main effect of slope on strike index (F=13.24, p<0.001) was found. Strike index during uphill running was significantly greater (i.e., landing with a more anterior foot strike) when compared with level (p<0.001, Cohen’s d=1.72) or downhill running (p<0.001, Cohen’s d=1.44) in either MIN or MAX. The majority of habitual rearfoot strike runners switched to midfoot strike during uphill running while maintaining a rearfoot strike pattern during level or downhill running. In summary, wearing either one of the two contrasting footwear (MIN or MAX) demonstrated no effect on impact loading and footstrike pattern in habitual rearfoot strike trail runners running on a natural trail with different slopes

Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV

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