The role of footwear in improving running economy: a systematic review with meta-analysis of controlled trials

This systematic review aimed to explore the impact of different types of footwear and footwear characteristics on the running economy (RE) of long-distance runners and providing guidance for running enthusiasts and clinical practice. A comprehensive search of Web of Science, PubMed, SPORTDiscous, SCOPUS, and the China National Knowledge Infrastructure (CNKI) databases from inception to April 2024 was performed. Trials evaluating the RE of adults participating in long-distance running included comparing different footwear characteristics. This review followed the PRISMA statement. Two reviewers screened titles and abstracts to make a relevant shortlist, then retrieved and evaluated full texts against inclusion criteria for eligibility. Two independent reviewers evaluated the methodological quality of each included analysis by employing the Physiotherapy Evidence Database Scale (PEDro scale). The standardized mean difference (SMD) for the results of RE studies in each study was calculated. Of the 1338 records retrieved, 26 studies were identified in the systematic review and meta-analysis. Limited evidence indicated that compared with shod running, barefoot running (SMD = - 0.50 [95% CI - 0.86, - 0.14], P = 0.006) and minimalist running (SMD = - 0.62 [95% CI - 0.83, - 0.42], P < 0.00001) had a positive impact on RE. Compared with barefoot running, minimalist running did not show a beneficial effect (SMD = 0.37 [95% CI - 0.07, 0.81], P = 0.10) on RE. Additionally, compared with the control condition, RE showed some improvement with increased footwear longitudinal bending stiffness (SMD = - 0.53 [95% CI - 0.90, - 0.17], P = 0.005) and cushioning (SMD = - 0.33 [95% CI - 0.61, 0.06], P = 0.02). However, compared with control, RE did not change with footwear comfort (SMD = - 0.11 [95% CI - 0.42, 0.21], P = 0.51). Barefoot running or minimalist running may be more economical than shod running, high longitudinal bending stiffness and high cushioning shoes could improve RE.

Transitioning to Barefoot Running Using a Minimalist Shoe Intermediary: A Prospective Cohort Study

OBJECTIVES

The objectives of this study are, first, to investigate the probability of runners successfully transitioning from running in a traditional shoe to barefoot. Second, to identify prognostic indicators of failure of transition to barefoot running.

METHODS

Over 20 wk, 76 healthy runners (female, 40; age, 35.04 yr [SD, 8.9 yr]; body weight, 69.9 kg [SD 13.4 kg]) attempted to transition from running in traditional shoes to running barefoot. A minimalist shoe was used as an intermediary. Participants ran for 4 wk exclusively in provided traditional shoes followed by 4 wk of transitioning to minimalist shoes. This process was repeated to transition to barefoot running. Participants were followed up until they withdrew from the study or successfully transitioned to running barefoot. A survival analysis examined the weeks of successful transition. Along with sex and age, baseline measures of traditional shoe overall comfort, footstrike pattern, midfoot width mobility and plantar foot pressure pain threshold were examined as prognostic variables for failure to transition using Cox regression.

RESULTS

The cumulative probability of successful transition to running barefoot was 70.8% (95% confidence interval [CI], 61%-83%). The primary footwear-related reason for withdrawal was pain, primarily in the foot ( n = 7), two runners had confirmed injuries. Runners exhibiting a rearfoot strike pattern and higher midfoot width mobility were more likely to fail to transition (hazard ratios [HR], 4.02; 95% CI, 1.33-12.16 and HR, 1.22; 95% CI, 1.05-1.42).

CONCLUSIONS

Most runners who wish to run barefoot will be able to transition. Our study indicates that there may be biomechanical and anatomical characteristics that are prognostic of failing to transition when using a 20-wk transition period and an intermediary minimalist shoe. Whether a different transition process increases the probability of a success remains to be seen.

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.

A systematic review of the effect of running shoes on running economy, performance and biomechanics: analysis by brand and model

This systematic review aims to synthesise the effects of current shoe models in each shoe category and their specific features on running economy, performance and biomechanics. Electronic databases such as Web of Science, SPORTDiscuss, PubMed and Scopus were used to identify studies from 2015 to date. Due to the existing lack of consensus to define running shoes, only studies that specified the shoe brand and models used to assess their effect over runners with a certain level of fitness and training routine were included. Quality assessment of cross-sectional and intervention studies was conducted by three independent raters using a modified version of the Quality Index and the PEDro scale, respectively. A total of 36 articles were finally included, involving the analysis of 61 different shoe models over 10 different topics (i.e., running economy, running performance, spatiotemporal parameters, ground reaction forces, joint stiffness, achilles tendon, plantar pressure, tibiofemoral load, foot strike pattern and joint coordination). With this review, runners and practitioners in the field that are concerned about selecting a suitable shoe for performance, training, or injury prevention functionality have clear information about the effects of the current shoe models and their specific features.

Foundational Principles and Adaptation of the Healthy and Pathological Achilles Tendon in Response to Resistance Exercise: A Narrative Review and Clinical Implications

Therapeutic exercise is widely considered a first line fundamental treatment option for managing tendinopathies. As the Achilles tendon is critical for locomotion, chronic Achilles tendinopathy can have a substantial impact on an individual's ability to work and on their participation in physical activity or sport and overall quality of life. The recalcitrant nature of Achilles tendinopathy coupled with substantial variation in clinician-prescribed therapeutic exercises may contribute to suboptimal outcomes. Further, loading the Achilles tendon with sufficiently high loads to elicit positive tendon adaptation (and therefore promote symptom alleviation) is challenging, and few works have explored tissue loading optimization for individuals with tendinopathy. The mechanism of therapeutic benefit that exercise therapy exerts on Achilles tendinopathy is also a subject of ongoing debate. Resultingly, many factors that may contribute to an optimal therapeutic exercise protocol for Achilles tendinopathy are not well described. The aim of this narrative review is to explore the principles of tendon remodeling under resistance-based exercise in both healthy and pathologic tissues, and to review the biomechanical principles of Achilles tendon loading mechanics which may impact an optimized therapeutic exercise prescription for Achilles tendinopathy.

Running into Fatigue: The Effects of Footwear on Kinematics, Kinetics, and Energetics

PURPOSE

Recent studies identified a redistribution of positive mechanical work from distal to proximal joints during prolonged runs, which might partly explain the reduced running economy observed with running-induced fatigue. Higher mechanical demand of plantar flexor muscle-tendon units, for example, through minimal footwear, can lead to an earlier onset of fatigue, which might affect the redistribution of lower extremity joint work during prolonged runs. Therefore, the purpose of this study was to examine the effects of a racing flat and cushioned running shoe on the joint-specific contributions to lower extremity joint work during a prolonged fatiguing run.

METHODS

On different days, 18 runners performed two 10-km runs with near-maximal effort in a racing flat and a cushioned shoe on an instrumented treadmill synchronized with a motion capture system. Joint kinetics and kinematics were calculated at 13 predetermined distances throughout the run. The effects of shoes, distance, and their interaction were analyzed using a two-factor repeated-measures ANOVA.

RESULTS

For both shoes, we found a redistribution of positive joint work from the ankle (-6%) to the knee (+3%) and the hip (+3%) throughout the entire run. Negative ankle joint work was higher (P < 0.01) with the racing flat compared with the cushioned shoe. Initial differences in foot strike patterns between shoes disappeared after 2 km of running distance.

CONCLUSIONS

Irrespective of the shoe design, alterations in the running mechanics occurred in the first 2 km of the run, which might be attributed to the existence of a habituation rather than fatigue effect. Although we did not find a difference between shoes in the fatigue-related redistribution of joint work from distal to more proximal joints, more systematical studies are needed to explore the effects of specific footwear design features.

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 designs, 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.

A 6-Week Transition to Maximal Running Shoes Does Not Change Running Biomechanics

BACKGROUND

A recent study suggested that maximal running shoes may increase the impact force and loading rate of the vertical ground-reaction force during running. It is currently unknown whether runners will adapt to decrease the impact force and loading rate over time.

PURPOSE

To compare the vertical ground-reaction force and ankle kinematics between maximal and traditional shoes before and after a 6-week acclimation period to the maximal shoe.

STUDY DESIGN

Controlled laboratory study.

METHODS

Participants ran in a traditional running shoe and a maximal running shoe during 2 testing sessions 6 weeks apart. During each session, 3-dimensional kinematics and kinetics were collected during overground running. Variables of interest included the loading rate, impact peak, and active peak of the vertical ground-reaction force, as well as eversion and dorsiflexion kinematics. Two-way repeated measures analyses of variance compared data within participants.

RESULTS

No significant differences were observed in any biomechanical variable between time points. The loading rate and impact peak were higher in the maximal shoe. Runners were still everted at toe-off and landed with less dorsiflexion, on average, in the maximal shoe.

CONCLUSION

Greater loading rates and impact forces were previously found in maximal running shoes, which may indicate an increased risk of injury. The eversion mechanics observed in the maximal shoes may also increase the risk of injury. A 6-week transition to maximal shoes did not significantly change any of these measures.

CLINICAL RELEVANCE

Maximal running shoes are becoming very popular and may be considered a treatment option for some injuries. The biomechanical results of this study do not support the use of maximal running shoes. However, the effect of these shoes on pain and injury rates is unknown.

The Physiology and Biomechanics of the Master Runner

The Master runner (age 35 y and above) represents a unique athletic patient. Lifelong participation in endurance running slows the inevitable age-related decline in aerobic function and muscular strength. Still, the Master runner does not escape the inevitable effects of aging. Master runners experience a steady decline in running performance, that is, typical and maximal running speeds, after the age of 50 years of age. Age-related declines in running performance are driven by a host of factors, including declining cardiovascular function, reduced muscular capacity, altered biomechanics, and greater susceptibility to running-related injury. This review discusses age-related changes in physiology, biomechanics, and running injury susceptibility and practical strategies to maximize running participation in the Master runner.

Long-Term Effects of Habitual Barefoot Running and Walking: A Systematic Review

INTRODUCTION

Barefoot locomotion is widely believed to be beneficial for motor development and biomechanics but are implied to be responsible for foot pathologies and running-related injuries. Although most of available studies focused on acute effects of barefoot running and walking little is known regarding the effects of long-term barefoot versus shod locomotion. The purpose of this study was to systematically review the literature to evaluate current evidence of habitual barefoot (HB) versus habitual shod locomotion on foot anthropometrics, biomechanics, motor performance, and pathologies.

METHODS

Four electronic databases were searched using terms related to habitually barefoot locomotion. Relevant studies were identified based on title, abstract, and full text, and a forward (citation tracking) and backward (references) search was performed. Risk of bias was assessed, data pooling, and meta-analysis (random effects model) performed and finally levels of evidence determined.

RESULTS

Fifteen studies with 8399 participants were included. Limited evidence was found for a reduced ankle dorsiflexion at footstrike (pooled effect size, -3.47; 95% confidence interval [CI], -5.18 to -1.76) and a lower pedobarographically measured hallux angle (-1.16; 95% CI, -1.64 to -0.68). HB populations had wider (0.55; 95% CI, 0.06-1.05) but no shorter (-0.22; 95% CI, -0.51 to 0.08) feet compared with habitual shod populations. No differences in relative injury rates were found, with limited evidence for a different body part distribution of musculoskeletal injuries and more foot pathologies and less foot deformities and defects in HB runners.

CONCLUSIONS

Only limited or very limited evidence is found for long-term effects of HB locomotion regarding biomechanics or health-related outcomes. Moreover, no evidence exists for motor performance. Future research should include prospective study designs.

Influence of cross-fit footwear on patellofemoral kinetics during running activities

The aim of this work was to examine the effects of barefoot, cross-fit, minimalist and conventional footwear on patellofemoral loading during running. Twelve cross-fit athletes ran at 4.0 m/s in each of the four footwear conditions. Lower limb kinematics were collected using an 8 camera motion analysis system and patellofemoral loading was estimated using a mathematical modelling approach. Differences between footwear were examined using one-way repeated measures ANOVA. The results showed the peak patellofemoral force and stress were significantly reduced when running barefoot (force = 3.42 BW & stress = 10.71 MPa) and in minimalist footwear (force = 3.73 BW & stress = 11.64 MPa) compared to conventional (force = 4.12 BW & stress = 12.69 MPa) and cross-fit (force = 3.97 BW & stress = 12.30 MPa) footwear. In addition, the findings also showed that patellofemoral impulse was significantly reduced when running barefoot (0.35 BW·s) and in minimalist footwear (0.36 BW·s) compared to conventional (0.42 BW·s) and cross-fit (0.38 BW·s) footwear. Given the proposed association between patellofemoral loading and patellofemoral disorders, the outcomes from the current investigation suggest that cross-fit athletes who select barefoot and minimalist footwear for their running activities may be at reduced risk from patellofemoral joint pathology in comparison to conventional and cross-fit footwear conditions.

The effect of minimalist, maximalist and energy return footwear of equal mass on running economy and substrate utilisation

The aim of the current study was to explore the effects of minimalist, maximalist and energy return footwear of equal mass on economy and substrate utilisation during steady state running. Ten male runners completed 6 min steady state runs in minimalist, maximalist and energy return footwear. The mass of the footwear was controlled by adding lead tape to the lighter shoes. Running economy, shoe comfort, rating of perceived exertion and % contribution of carbohydrate to total calorie expenditure were assessed. Participants also subjectively indicated which shoe condition they preferred for running. Differences in shoe comfort and physiological parameters were examined using paired samples t-tests, whilst shoe preferences were tested using a chi-square test. The results showed firstly that running economy was significantly improved in the energy return (35.9 ml∙kg/min) compared to minimalist footwear (37.8 ml∙kg/min). In addition % carbohydrate was significantly greater in the minimalist (76.4%) in comparison to energy return footwear (72.9%). As running economy was improved and carbohydrate utilisation reduced in the energy return in comparison to minimalist footwear, the current investigation shows that these footwear are more economical when shoe mass is controlled.