Increased footwear comfort is associated with improved running economy - a systematic review and meta-analysis

Running Shoes of the Postmodern Footwear Era: A Narrative Overview of Advanced Footwear Technology

The modern era of running shoes began in the 1960s with the introduction of simple polymer midsole foams, and it ended in the late 2010s with the introduction of advanced footwear technology (AFT). AFT is characterized by highly compliant, resilient, and lightweight foams with embedded, rigid, longitudinal architecture. This footwear complex improves a runner's efficiency, and it introduced a step change in running performance. Purpose: This review serves to examine the current state of knowledge around AFT-what it is and what we know about its ingredients, what benefits it confers to runners, and what may or may not mediate that benefit. We also discuss the emerging science around AFT being introduced to track-racing spikes and how it is currently regulated in sporting contexts. Conclusions: AFT has changed running as a sport. The construction of AFT is grossly understood, but the nature of the interacting elements is not. The magnitude of the enhancement of a runner's economy and performance has been characterized and modeled, but the nuanced factors that mediate those responses have not. With these knowns and unknowns, we conclude the review by providing a collection of best practices for footwear researchers, advice for runners interested in AFT, and a list of pertinent items for further investigation.

Factors that influence field hockey footwear selection: An online survey

BACKGROUND

Little is known about factors that influence footwear selection by field hockey players.

METHODS

An online survey was used to collect data on participant demographics and physical characteristics, factors influencing footwear selection, perceptions regarding footwear design features on injury and performance, and experiences regarding usability. Nominal and ordinal data were described as absolute frequencies and relative frequencies. Free text responses were analysed using content analysis. Sex-related differences in quantitative and qualitative data were explored.

RESULTS

A total of 401 hockey players completed the survey. Participants reported that fit, comfort, support, and cushioning were the most important factors when selecting hockey footwear. Most hockey players believed that stud design could influence athletic performance (65%) and injury risk (63%) but reported having no preference on outsole design or stud shape. Most participants (63%) used hockey-specific footwear, but 46% of female hockey players did not, with 40% using trail running footwear instead. Qualitative analysis revealed that hockey players, particularly female participants, encounter difficulties finding properly fitting footwear. They desire more options for wide or narrow feet and face challenges in accessing suitable hockey shoes due to limited choices and availability.

CONCLUSIONS

With over a third of field hockey players not using hockey-specific footwear, future research should attempt to understand the reasons and assess the impact of different footwear features on comfort, performance, injury risk, and usability.

Does orthotics use improve comfort, speed, and injury rate during running? A randomised control trial

BACKGROUND

Running is a hugely popular sport. Unfortunately, running-related injury (RRI) rates are high, particularly amongst amateur and recreational runners. Finding ways to reduce RRI rates and maximise comfort and performance for runners is important. Evidence regarding whether orthotics can successfully improve these parameters is limited and contradicting. Further research is required to provide runners with clearer guidance on the usefulness of orthotics.

AIM

To investigate the effect of Aetrex Orthotics on comfort, speed and RRI rates during recreational running.

METHODS

One hundred and six recreational runners were recruited on a voluntary basis via running clubs and social media pages and randomised into either the intervention or control group. Participants in the intervention group ran with Aetrex L700 Speed Orthotics inserted in their usual running shoes, whilst participants in the control group ran in their usual running shoes with no orthotics. The study ran for an 8-wk period. Participants provided data relating to running comfort, distance, and time during weeks 3-6. Participants provided data relating to any RRIs they sustained during all 8 wks. Running distance and time were used to calculate running speed in miles per hour (mph). For each outcome variable, 95% confidence intervals and P values were calculated to assess the statistical significance between the groups. For comfort and speed data, univariate multi-level analysis was performed, and for outcome variables with significant between group differences, multi-level multivariate analysis was performed to evaluate any confounding effects of gender and age.

RESULTS

Ninety-four participants were included in the final analysis (drop-out rate = 11%). Comfort and speed from 940 runs and 978 injury data reports were analysed. Participants who ran with orthotics reported, on average, speeds 0.30 mph faster (P = 0.20) and comfort scores 1.27 points higher (P ≤ 0.001) than participants who ran with no orthotics. They were also 2.22 times less likely to sustain an injury (P = 0.08) than participants who ran with no orthotics. However, findings were only significant for comfort and not for speed or injury rates. Age and gender were found to be significant predictors of comfort. However, the improvements in comfort reported by participants who ran with orthotics were still significant after adjusting for age and gender.

CONCLUSION

This study found orthotics to improve comfort and speed and prevent RRIs whilst running. However, these findings were only statistically significant for comfort.

No Effect of EVA and TPU Custom Foot Orthoses on Mechanical Asymmetries during Acute Intense Fatigue

This study examined the impact of custom foot orthoses made of ethyl-vinyl acetate (EVA) and expanded thermoplastic polyurethane (TPU) materials, both compared to a control condition (CON; shoes only), on mechanical asymmetries during repeated treadmill sprints. Eighteen well-trained male runners executed eight, 5-s sprints (rest: 25 s) on an instrumented motorized treadmill in three footwear conditions (EVA, TPU, and CON). We evaluated the group mean asymmetry scores using the ‘symmetry angle’ (SA) formula, which assigns a score of 0% for perfect symmetry and a score of 100% for perfect asymmetry. There was no condition (all p ≥ 0.053) or time (p ≥ 0.074) main effects, nor were there any significant time × condition interactions on SA scores for any variables (p ≥ 0.640). Mean vertical, horizontal, and total forces presented mean SA values (pooled values for the three conditions) of 2.6 ± 1.9%, 2.9 ± 1.6%, and 2.4 ± 1.8%, respectively. Mean SA scores were ~1–3% for contact time (1.5 ± 0.5%), flight time (3.0 ± 0.3%), step frequency (1.1 ± 0.5%), step length (1.9 ± 0.7%), vertical stiffness (2.1 ± 0.9%), and leg stiffness (2.4 ± 1.1%). Mean SA scores were ~2–6.5% for duration of braking (4.1 ± 1.6%) and propulsive (2.4 ± 1.0%) phases, and peak braking (6.2 ± 2.9%) and propulsive (2.1 ± 1.4%) forces. In well-trained runners facing intense fatigue, wearing custom foot orthoses did not modify the observed low-to-moderate natural stride mechanical asymmetries.

Measurement and reporting of footwear characteristics in running biomechanics: A systematic search and narrative synthesis of contemporary research methods

This review aimed to synthesise the methods for assessing and reporting footwear characteristics among studies evaluating the effect of footwear on running biomechanics. Electronic searches of Scopus®, EBSCO, PubMed®, ScienceDirect®, and Web of Science® were performed to identify original research articles of the effect of running footwear on running biomechanics published from 1^st January 2015 to 7^th October 2020. Risk of bias among included studies was not assessed. Results were presented via narrative synthesis. Eligible studies compared the effect of two or more footwear conditions in adult runners on a biomechanical parameter. Eighty-seven articles were included and data from 242 individual footwear were extracted. Predominantly, studies reported footwear taxonomy (i.e., classification) and manufacturer information, however omitted detail regarding the technical specifications of running footwear and did not use validated footwear reporting tools. There is inconsistency among contemporary studies in the methods by which footwear characteristics are assessed and reported. These findings point towards a need for consensus regarding the reporting of these characteristics within biomechanical studies to facilitate the conduct of systematic reviews and meta-analyses pertaining to the effect of running footwear on running biomechanics.

Non-South East Asians have a better running economy and different anthropometrics and biomechanics than South East Asians

Running biomechanics and ethnicity can influence running economy (RE), which is a critical factor of running performance. Our aim was to compare RE of South East Asian (SEA) and non-South East Asian (non-SEA) runners at several endurance running speeds (10-14 km/h) matched for on-road racing performance and sex. Secondly, we explored anthropometric characteristics and relationships between RE and anthropometric and biomechanical variables. SEA were 6% less economical (p = 0.04) than non-SEA. SEA were lighter and shorter than non-SEA, and had lower body mass indexes and leg lengths (p ≤ 0.01). In terms of biomechanics, a higher prevalence of forefoot strikers in SEA than non-SEA was seen at each speed tested (p ≤ 0.04). Furthermore, SEA had a significantly higher step frequency (p = 0.02), shorter contact time (p = 0.04), smaller footstrike angle (p < 0.001), and less knee extension at toe-off (p = 0.03) than non-SEA. Amongst these variables, only mass was positively correlated to RE for both SEA (12 km/h) and non-SEA (all speeds); step frequency, negatively correlated to RE for both SEA (10 km/h) and non-SEA (12 km/h); and contact time, positively correlated to RE for SEA (12 km/h). Despite the observed anthropometric and biomechanical differences between cohorts, these data were limited in underpinning the observed RE differences at a group level. This exploratory study provides preliminary indications of potential differences between SEA and non-SEA runners warranting further consideration. Altogether, these findings suggest caution when generalizing from non-SEA running studies to SEA runners.