Running Footwear Research Articles

Effects of specific and non-specific court footwear on anterior cruciate ligament loading during a maximal change of direction manoeuvre

The aim of the current investigation was to examine the effects of tennis shoes and running footwear on the loads experienced by the anterior cruciate ligament (ACL) during a maximal change of direction task. Thirteen male participants performed maximal change of direction movements in tennis shoes and running footwear. Lower limb kinematics were collected using an eight-camera motion capture system and ground reaction forces were quantified using an embedded force platform. ACL loading was examined via a musculoskeletal modelling approach and the frictional properties of the footwear were examined using ground reaction force information. Differences in ACL loading parameters between footwear were examined using one-way repeated measures ANOVA and multiple regression analyses were used to determine frictional predictors of ACL loading. Peak ACL force was significantly larger in the tennis shoes (2308.35 N) in relation to running footwear (1859.21 N) conditions. In addition, it was shown that the peak rotational moment was a significant predictor of peak ACL force in the tennis shoes (adjusted R2 = 0.68) and running footwear (adjusted R2 = 0.61) conditions. The findings from the current investigation indicate that the specific tennis shoes examined in the current investigation may place athletes at increased risk from ACL pathology during maximal change of direction movements. However, further exploration using a more ecologically valid research design is required before this notion can be truly substantiated.

The Preferred Movement Path Paradigm: Influence of Running Shoes on Joint Movement.

(A) To quantify differences in lower extremity joint kinematics for groups of runners subjected to different running footwear conditions, and (B) to quantify differences in lower extremity joint kinematics on an individual basis for runners subjected to different running footwear conditions. Three-dimensional ankle and knee joint kinematics were collected for 35 heel-toe runners when wearing three different running shoes and when running barefoot. Absolute mean differences in ankle and knee joint kinematics were computed between running shoe conditions. The percentage of individual runners who displayed differences below a 2°, 3°, and 5° threshold were also calculated. The results indicate that the mean kinematics of the ankle and knee joints were similar between running shoe conditions. Aside from ankle dorsiflexion and knee flexion, the percentage of runners maintaining their movement path between running shoes (i.e., less than 3°) was in the order of magnitude of about 80% to 100%. Many runners showed ankle and knee joint kinematics that differed between a conventional running shoe and barefoot by more than 3°, especially for ankle dorsiflexion and knee flexion. Many runners stay in the same movement path (the preferred movement path) when running in various different footwear conditions. The percentage of runners maintaining their preferred movement path depends on the magnitude of the change introduced by the footwear condition.

Evaluating running footwear

Evaluating running footwear

Effect of Footwear on Dynamic Stability during Single-leg Jump Landings.

Barefoot and minimal footwear running has led to greater interest in the biomechanical effects of different types of footwear. The effect of running footwear on dynamic stability is not well understood. The purpose of this study was to compare dynamic stability and impact loading across 3 footwear conditions; barefoot, minimal footwear and standard running shoes. 25 injury free runners (21 male, 4 female) completed 5 single-leg jump landings in each footwear condition. Dynamic stability was assessed using the dynamic postural stability index and its directional components (mediolateral, anteroposterior, vertical). Peak vertical ground reaction force and vertical loadrates were also compared across footwear conditions. Dynamic stability was dependent on footwear type for all stability indices (ANOVA, p<0.05). Post-hoc tests showed dynamic stability was greater when barefoot than in running shoes for each stability index (p<0.02) and greater than minimal footwear for the anteroposterior stability index (p<0.01). Peak vertical force and average loadrates were both dependent on footwear (p≤0.05). Dynamic stability, peak vertical force, and average loadrates during single-leg jump landings appear to be affected by footwear type. The results suggest greater dynamic stability and lower impact loading when landing barefoot or in minimal footwear.

Footwear characteristics are related to running mechanics in runners with patellofemoral pain

Running footwear is known to influence step rate, foot inclination at foot strike, average vertical loading rate (VLR) and peak patellofemoral joint (PFJ) force. However, the association between the level of minimalism of running shoes and running mechanics, especially with regards to these relevant variables for runners with patellofemoral pain (PFP), has yet to be investigated. The objective of this study was to explore the relationship between the level of minimalism of running shoes and habitual running kinematics and kinetics in runners with PFP. Running shoes of 69 runners with PFP (46 females, 23 males, 30.7±6.4years) were evaluated using the Minimalist Index (MI). Kinematic and kinetic data were collected during running on an instrumented treadmill. Principal component and correlation analyses were performed between the MI and its subscales and step rate, foot inclination at foot strike, average VLR, peak PFJ force and peak Achilles tendon force. Higher MI scores were moderately correlated with lower foot inclination (r=−0.410, P<0.001) and lower peak PFJ force (r=−0.412, P<0.001). Moderate correlations also showed that lower shoe mass is indicative of greater step rate (ρ=0.531, P<0.001) and lower peak PFJ force (ρ=−0.481, P<0.001). Greater shoe flexibility was moderately associated with lower foot inclination (ρ=−0.447, P<0.001). Results suggest that greater levels of minimalism are associated with lower inclination angle and lower peak PFJ force in runners with PFP. Thus, this population may potentially benefit from changes in running mechanics associated with the use of shoes with a higher level of minimalism.

서 있는 자세에서 기능성 신발과 운동화의 자세 안정성 비교분석

서 있는 자세에서 기능성 신발과 운동화의 자세 안정성 비교분석

Effects of shoes on kinetics and kinematics of the squash forward lunge in male players

Squash is associated with a high incidence of chronic injuries. Currently there is a trend in many sports for players to select minimalist footwear. The aim of the current investigation was to examine the effects of squashspecific, running shoes and minimalist footwear on the kinetics and 3-D kinematics of the lunge movement in squash players. Twelve male squash players performed lunge movements whilst wearing minimalist, running shoe and squash-specific footwear. 3-D kinematics of the lower extremities were measured using an eightcamera motion analysis system alongside kinetic and tibial acceleration information which were obtained using a force platform and an accelerometer. Differences between footwear were examined using one-way repeated measures ANOVA. The results show firstly that loading rate parameters were significantly greater in the minimalist (average = 85.36B.W/s and instantaneous = 179.09B.W/s) footwear in relation to the squashspecific (average = 38.66 B.W/s and instantaneous = 50.73B.W/s) and running footwear (average = 37.62B.W/s and instantaneous = 48.14B.W/s). In addition, tibial acceleration parameters were also significantly greater in the minimalist (peak tibial acceleration = 8.45 g and tibial acceleration slope = 422.28g/s) footwear in relation to the squash-specific (peak tibial acceleration = 4.33 g and tibial acceleration slope = 182.57g/s) and running footwear (peak tibial acceleration = 4.81 g and tibial acceleration slope = 226.72g/s). The significant increase in impact loading in the minimalist footwear therefore suggests this type of shoe may place squash players at an increased risk of developing impact-related chronic injuries.

Overall Preference of Running Shoes Can Be Predicted by Suitable Perception Factors Using a Multiple Regression Model.

This study examined (a) the strength of four individual footwear perception factors to influence the overall preference of running shoes and (b) whether these perception factors satisfied the nonmulticollinear assumption in a regression model. Running footwear must fulfill multiple functional criteria to satisfy its potential users. Footwear perception factors, such as fit and cushioning, are commonly used to guide shoe design and development, but it is unclear whether running-footwear users are able to differentiate one factor from another. One hundred casual runners assessed four running shoes on a 15-cm visual analogue scale for four footwear perception factors (fit, cushioning, arch support, and stability) as well as for overall preference during a treadmill running protocol. Diagnostic tests showed an absence of multicollinearity between factors, where values for tolerance ranged from .36 to .72, corresponding to variance inflation factors of 2.8 to 1.4. The multiple regression model of these four footwear perception variables accounted for 77.7% to 81.6% of variance in overall preference, with each factor explaining a unique part of the total variance. Casual runners were able to rate each footwear perception factor separately, thus assigning each factor a true potential to improve overall preference for the users. The results also support the use of a multiple regression model of footwear perception factors to predict overall running shoe preference. Regression modeling is a useful tool for running-shoe manufacturers to more precisely evaluate how individual factors contribute to the subjective assessment of running footwear.

Biofidelic mechanical ageing of ethylene vinyl acetate running footwear midsole foam

Simple manipulation of force–time input is a potential strategy to increase the biofidelity of running footwear mechanical ageing. The purpose of this study was to compare a Dwell protocol, which incorporated a recovery period characteristic of the float phase of running, to traditional sinusoidal ageing. A second aim was to use the protocol to compare the mechanical ageing performance of foam, a halved commercial running shoe, and a cylindrical plug cut from a running shoe to quantify effects due to testing geometry and to estimate the contribution of midsole foam to shoe energy management. Dwell was more biofidelic and less aggressive than Sine because (1) net displacement and energy absorption were greater than Sine and (2) net displacement and energy absorption decreased at a slower rate than Sine. Using a 60 mm diameter cylindrical plug to estimate the performance of a halved shoe with 100 mm contact area led to 20% overestimation of energy absorption. Comparing the performance of a slab of foam and a cylindrical plug cut out from a shoe, the midsole was estimated to manage 90% of the energy. Differences between sample types were also related to stiffness, yield behavior, and resulting hysteresis curve shapes, which revealed that the outsole improved sample deformation and durability. Overall, results supported that Dwell improved the biofidelity of mechanical ageing, testing geometry is an important consideration in experimental design, and most of the energy was managed by the midsole.

ADHERENCE TO SIX MONTHS OF INSTRUCTED MINIMALIST AND BAREFOOT RUNNING TRAINING

ABSTRACT Introduction: The interest in minimalist and barefoot running is growing continuously. However, there is no data on how many runners drop out during this process. Objective: To describe the adhesion and dropout rates of a six-month instructed training program based on barefoot and minimalist footwear running. Methods: Thirty-four recreational runners participated in the study: 20 runners started the race training barefoot, while 14 runners were involved in training with minimalist footwear. Adhesion to intervention programs was evaluated through training spreadsheets and recording attendance at training sessions, while dropouts were evaluated at the end of training. A questionnaire was sent to participants who dropped out of the training, to obtain information related on why they had abandoned it. Results: Considering all participants (n=34), 41.2% of the runners completed six months with reduced plantar protection; 70% of all dropouts occurred in barefoot training; the main reasons for leaving the training were injury/pain (40%) and lack of time/suitable place for training (40%); and the majority of dropouts (50%) occurred in the first month of training. Barefoot training (n=20) showed 70% dropouts, 57.1% of them due to lack of time/suitable place for training; and 71.4% of the dropouts occurred in the first month of the intervention. The training with minimalist footwear (n=14) had fewer dropouts (42.9%) than the barefoot training, all of them due to injury/pain; 50% of them occurred in the third month of intervention. Conclusion: Dropouts usually occur at the beginning of training. Training involving barefoot running has more dropouts than training with minimalist footwear. Intervention programs lasting six months based on minimalist footwear/barefoot seems to have similar adhesion to other supervised exercise programs. The main reasons for dropping out are injury/pain and lack of time/suitable place to run.

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A-27 Thematic Poster - Running Footwear: Less or More? Wednesday, June 1, 2016, 9: 30 AM - 11: 30 AM Room: 103: PDF Only

Differences in Running Economy among Experienced Runners Wearing both Minimal and Traditional Running Footwear

Differences in Running Economy among Experienced Runners Wearing both Minimal and Traditional Running Footwear

The effect of barefoot and barefoot inspired footwear running on tibiofemoral kinetics

PurposeThe current investigation aimed to examine the effects of running barefoot and in conventional and barefoot inspired footwear on the loads borne by the tibiofemoral joint.MethodsFifteen male participants ran at 4.0 m/s over a force platform whilst running barefoot, in barefoot inspired footwear and also in conventional footwear. Lower body kinematics were collected using an eight-camera motion capture system. Peak tibiofemoral force, peak tibiofemoral stress, and tibiofemoral load rate were extracted and compared between footwear via one-way repeated measures ANOVA.ResultsThe results showed that the tibiofemoral instantaneous load rate was significantly lower in conventional footwear (106.63 BW/s) in comparison with barefoot running (173.87 BW/s), Vibram Five Fingers (160.17 BW/s), Merrell (155.32 BW/s), Inov-8 (167.79 BW/s), and Nike Free (144.72 BW/s).ConclusionsThis indicates that running barefoot and in barefoot inspired footwear may place runners at increased risk from running-related tibiofemoral pathologies.

Assessing the effectiveness of micro-spring technology to reduce initial and peak loading rates when integrated into running footwear

Running has long been one of the world’s most popular recreational activities. The current total of European runners exceeds 80 million, approximately, 36% of 15�65-year-old European population. Running is one of the most widespread activities during which overuse injuries of the lower extremity occur (Hreljac, 2004). It has been estimated that up to 70% of runners will sustain an overuse injury during any one year period (Caspersen et al., 1984). Previous work has shown that impact forces and high loading rates are linked to injury rates in runners (Davis, Bowser, & Mullineaux, 2010). Despite the apparent advances in footwear technology and the plethora footwear choices available, we are yet to see a reduction in injury rates amongst runners.

Segmented midsole hardness in the midfoot to forefoot region of running shoes alters subjective perception and biomechanics during heel-toe running revealing potential to enhance footwear

Purpose: Dual density midsole constructions at the lateral rearfoot and medial midfoot provide opportunities to improve cushioning and stability of running shoes. By similar mechanisms, non-uniform midsole density across the medio-lateral direction at the midfoot to forefoot may allow better negotiation of different loading magnitudes of the medial and lateral midfoot to forefoot during running. Thus, the effect of segmented midsole hardness at the midfoot to forefoot of running shoes on perception and biomechanics was examined.Methods: Four custom-made running shoes featured a three section longitudinal hardness pattern at midfoot to forefoot. The central section as well as the rearfoot section always had consistent medium hardness, whereas medial and lateral sections were systematically softer or harder. A sample of 24 runners participated in visual analogue scale based perception measurements and in recording of in-shoe plantar pressures, ground reaction forces, and multi-segment foot kinematics. Shoe effects were analysed by repeated measures analyses of variance (ANOVA) (p<.05), followed by least significant difference (LSD) and Bonferroni adjusted post-hoc tests (p<.05) for discrete variables. Interaction of shank and foot segments was also analysed using motion-time curves.Results: Runners distinguished midsole hardness at the medial (p = .009) but not at the lateral midfoot to forefoot and indicated a trend (p = .069) preferring softer medial hardness. Plantar peak pressure (medial: p = .006, lateral: p = .000) and relative loads (medial: p = .000, lateral: p = .000) were increased when midsole sections were harder. Ground contact time (p = .045) and maximum loading rate I (p = .016) were higher for shoes having softer medial hardness, while rearfoot (p = .040) and forefoot (p = .001) showed increased maximum ankle eversion for these conditions.Conclusion: Segmented running shoe midsole hardness across the medio-lateral direction of the midfoot to forefoot influences subjective comfort and biomechanical forefoot stability. Findings allow systematic approaches to improve both features, thereby creating enhanced running footwear.

The re-emergence of the minimal running shoe.

The running shoe has gone through significant changes since its inception. The purpose of this paper is to review these changes, the majority of which have occurred over the past 50 years. Running footwear began as very minimal, then evolved to become highly cushioned and supportive. However, over the past 5 years, there has been a reversal of this trend, with runners seeking more minimal shoes that allow their feet more natural motion. This abrupt shift toward footwear without cushioning and support has led to reports of injuries associated with minimal footwear. In response to this, the running footwear industry shifted again toward the development of lightweight, partial minimal shoes that offer some support and cushioning. In this paper, studies comparing the mechanics between running in minimal, partial minimal, and traditional shoes are reviewed. The implications for injuries in all 3 conditions are examined. The use of minimal footwear in other populations besides runners is discussed. Finally, areas for future research into minimal footwear are suggested.

The effect of minimal shoes on arch structure and intrinsic foot muscle strength

BackgroundThis prospective study explored the effects of endurance running (ER) in minimal versus standard running shoes on the foot's superficial layer intrinsic muscles and the function of the longitudinal arch. Our hypothesis was that running in minimal shoes would cause hypertrophy in these muscles and lead to higher, stronger, stiffer arches. MethodsThe hypothesis was tested using a sample of 33 healthy runners randomized into two groups, a control group shod in traditional running footwear and an experimental group shod in minimal support footwear, whose feet were scanned in an MRI before and after a 12-week training regime. Running kinematics as well as arch stiffness and height were also assessed before and after the treatment period. ResultsAnalysis of anatomical cross-sectional areas and muscle volumes indicate that the flexor digitorum brevis muscle became larger in both groups by 11% and 21%, respectively, but only the minimally shod runners had significant areal and volumetric increases of the abductor digiti minimi of 18% and 22%, respectively, and significantly increased longitudinal arch stiffness (60%). ConclusionThese results suggest that endurance running in minimal support footwear with 4 mm offset or less makes greater use of the spring-like function of the longitudinal arch, thus leading to greater demands on the intrinsic muscles that support the arch, thereby strengthening the foot.

Investigation into the kinetics and kinematics during running in the heelless shoe

Background: Recent evidence suggests that runners who habitually rearfoot strike suffer higher rates of chronic injuries compared to those who adopt a mid/forefoot strike pattern. Based on this information new experimental heelless footwear was developed with the aim of mediating a mid/forefoot strike pattern.Objectives: The aim of the current investigation was to examine the three-dimensional (3D) kinematics and ground reaction forces (GRFs) of running in conventional footwear in comparison to the heelless shoes.Methods: Twelve male participants ran at 4.0 m.s−1±5% in each footwear condition. Angular joint kinematics from the hip, knee and ankle in the sagittal, coronal and transverse planes were measured using an eight-camera optoelectric motion capture system. Synchronous ground reaction forces were also obtained allowing impact load parameters and estimates of Achilles tendon force to be quantified. Differences in GRFs and 3D kinematics between footwear were assessed using paired t-tests.Results: The kinematic analysis indicated that, in comparison to the conventional running footwear, the heelless shoes were associated with significantly greater plantarflexion at foot strike and peak ankle eversion angle. Furthermore, the GRF analysis revealed that, compared to the conventional footwear, impact parameters were significantly lower in the heelless footwear.Conclusions: Given the reduction in impact loading rates and increases in ankle eversion that were observed in heelless footwear, running in this type of footwear may reduce the incidence of chronic injuries linked to excessive impact forces. However, it may increase the injury potential that is associated with excessive ankle eversion.

Barefoot Versus Shoe Running: From the Past to the Present

Introduction: Barefoot running is not a new concept, but relatively few people choose to engage in barefoot running on a regular basis. Despite the technological developments in modern running footwear, as many as 79% of runners are injured every year. Although benefits of barefoot running have been proposed, there are also potential risks associated with it. Objective: To review the evidence-based literature concerning barefoot/minimal footwear running and the implications for the practicing physician. Materials and Methods: Multiple publications were reviewed using an electronic search of databases such as Medline, Cinahl, Embase, PubMed, and Cochrane Database from inception until August 30, 2013 using the search terms barefoot running, barefoot running biomechanics, and shoe vs. barefoot running. Results: Ninety-six relevant articles were found. Most were reviews of biomechanical and kinematic studies. Analysis: There are notable differences in gait and other parameters between barefoot running and shoe running. Based on these findings and much anecdotal evidence, one could conclude that barefoot runners should have fewer injuries, better performance, or both. Several athletic shoe companies have designed running shoes that attempt to mimic the barefoot condition, and thus garner the purported benefits of barefoot running. Conclusion: Although there is no evidence that confirms or refutes improved performance and reduced injuries in barefoot runners, many of the claimed disadvantages to barefoot running are not supported by the literature. Nonetheless, it seems that barefoot running may be an acceptable training method for athletes and coaches, as it may minimize the risks of injury.

A Test of the Metabolic Cost of Cushioning Hypothesis during Unshod and Shod Running

This study aimed to investigate the effects of surface and shoe cushioning on the metabolic cost of running. In running, the leg muscles generate force to cushion the impact with the ground. External cushioning (surfaces or shoes) may reduce the muscular effort needed for cushioning and thus reduce metabolic cost. Our primary hypothesis was that the metabolic cost of unshod running would decrease with a more cushioned running surface. We also hypothesized that because of the counteracting effects of shoe cushioning and mass, unshod running on a hard surface would have approximately the same metabolic cost as running in lightweight, cushioned shoes. To test these hypotheses, we attached 10- and 20-mm-thick slats of the same foam cushioning used in running shoe midsoles to the belt of a treadmill that had a rigid deck. Twelve subjects who preferred a midfoot strike pattern and had substantial barefoot/minimalist running experience ran without shoes on the normal treadmill belt and on each thickness of foam. They also ran with lightweight, cushioned shoes on the normal belt. We collected V˙O2 and V˙CO2 to calculate the metabolic power demand and used a repeated-measures ANOVA to compare between conditions. Compared to running unshod on the normal belt, running unshod on the 10-mm-thick foam required 1.63% ± 0.67% (mean ± SD) less metabolic power (P = 0.034) but running on the 20-mm-thick foam had no significant metabolic effect. Running with and without shoes on the normal belt had similar metabolic power demands, likely because the beneficial energetic effects of cushioning counterbalanced the detrimental effects of shoe mass. On average, surface and shoe cushioning reduce the metabolic power required for submaximal running.