Efficacy of motion control shoes for reducing excessive rearfoot motion in fatigued runners

Effect of surface inclination on vertical loading rate and footstrike pattern in trail and road runners

Trail runners have been reported to be more injury prone than road runners. Limited past studies have examined the difference in the running biomechanics between the two groups of runners. More importantly, the effect of surface inclination has not been fully investigated. Hence, this study examined the effect of surface inclination on running biomechanics in trail and road runners. Twenty trails and 20 road runners were recruited in this study. Trail runners appeared to be more experienced and had longer training distance per week (p < 0.001) compared to road runners. All participants ran at a self-selected pace on an instrumented treadmill in three inclination conditions (i.e., level, +10% uphill and -10% downhill) in a random order. Vertical average loading rate (VALR), vertical instantaneous loading rate (VILR) and footstrike angle (FSA) were measured using established methods. Trail runners experienced greater VILR (p = 0.039, Cohen's d = 2.9) with a greater FSA (p = 0.002, Cohen's d = 1.1) during downhill running than road runners. No significant differences in VALR, VILR and FSA were found between the two groups during level and uphill running. Our findings provide potential biomechanical rationale to explain a higher injury incidence among trail runners.

Towards functionally individualised designed footwear recommendation for overuse injury prevention: a scoping review

Injury prevention is essential in running due to the risk of overuse injury development. Tailoring running shoes to individual needs may be a promising strategy to reduce this risk. Novel manufacturing processes allow the production of individualised running shoes that incorporate features that meet individual biomechanical and experiential needs. However, specific ways to individualise footwear to reduce injury risk are poorly understood. Therefore, this scoping review provides an overview of (1) footwear design features that have the potential for individualisation; and (2) the literature on the differential responses to footwear design features between selected groups of individuals. These purposes focus exclusively on reducing the risk of overuse injuries. We included studies in the English language on adults that analysed: (1) potential interaction effects between footwear design features and subgroups of runners or covariates (e.g., age, sex) for running-related biomechanical risk factors or injury incidences; (2) footwear comfort perception for a systematically modified footwear design feature. Most of the included articles (n = 107) analysed male runners. Female runners may be more susceptible to footwear-induced changes and overuse injury development; future research should target more heterogonous sampling. Several footwear design features (e.g., midsole characteristics, upper, outsole profile) show potential for individualisation. However, the literature addressing individualised footwear solutions and the potential to reduce biomechanical risk factors is limited. Future studies should leverage more extensive data collections considering relevant covariates and subgroups while systematically modifying isolated footwear design features to inform footwear individualisation.

Fatigue related changes in rearfoot eversion: a means of functionally grouping runners?

Fatigue alters rearfoot kinematics on an individual basis and may offer a means of functionally grouping runners. This proof of concept study aimed to determine whether fatigue related changes in rearfoot eversion could be used to functionally group runners. Sixteen male recreational runners had their frontal plane rearfoot kinematics recorded by a three-dimensional motion capture system before and after a 5km run. The magnitude of change in frontal plane rearfoot kinematics pre- to post-fatigue was calculated and K-means clustering used to identify functional groups based upon these changes. T-tests with statistical parametric mapping were used to compare fatigue related changes both within and between clusters. Two clusters or functional groups were evident within the data set. Nine participants were allocated to cluster 1 and displayed small and insignificant changes in frontal plane rearfoot motion post-fatigue. In contrast, the remaining seven participants were assigned to cluster 2 and displayed significant increases in rearfoot eversion between 3 and 84% of the stance phase post-fatigue. These findings prove the concept that fatigue related changes in rearfoot eversion can be used to functionally group participants. Additionally, the differing fatigue related changes reported by each group may alter the injury risk, training and footwear needs of each group. HighlightsFatigue related changes in frontal plane rearfoot motion can be used to functionally group individuals.Cluster 1 display small and insignificant fatigue related changes, which suggests they can maintain their habitual movement pathway.Cluster 2 displayed significant increases in rearfoot eversion for the majority of the stance phase, suggesting an inability to maintain their habitual movement pathway, which may increase injury risk.

Running shoes for preventing lower limb running injuries in adults

BACKGROUND

Lower-limb running injuries are common. Running shoes have been proposed as one means of reducing injury risk. However, there is uncertainty as to how effective running shoes are for the prevention of injury. It is also unclear how the effects of different characteristics of running shoes prevent injury.

OBJECTIVES

To assess the effects (benefits and harms) of running shoes for preventing lower-limb running injuries in adult runners.

SEARCH METHODS

We searched the following databases: CENTRAL, MEDLINE, Embase, AMED, CINAHL Plus and SPORTDiscus plus trial registers WHO ICTRP and ClinicalTrials.gov. We also searched additional sources for published and unpublished trials. The date of the search was June 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs involving runners or military personnel in basic training that either compared a) a running shoe with a non-running shoe; b) different types of running shoes (minimalist, neutral/cushioned, motion control, stability, soft midsole, hard midsole); or c) footwear recommended and selected on foot posture versus footwear not recommended and not selected on foot posture for preventing lower-limb running injuries. Our primary outcomes were number of people sustaining a lower-limb running injury and number of lower-limb running injuries. Our secondary outcomes were number of runners who failed to return to running or their previous level of running, runner satisfaction with footwear, adverse events other than musculoskeletal injuries, and number of runners requiring hospital admission or surgery, or both, for musculoskeletal injury or adverse event.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and performed data extraction and risk of bias assessment. The certainty of the included evidence was assessed using GRADE methodology.

MAIN RESULTS

We included 12 trials in the analysis which included a total of 11,240 participants, in trials that lasted from 6 to 26 weeks and were carried out in North America, Europe, Australia and South Africa. Most of the evidence was low or very low certainty as it was not possible to blind runners to their allocated running shoe, there was variation in the definition of an injury and characteristics of footwear, and there were too few studies for most comparisons. We did not find any trials that compared running shoes with non-running shoes. Neutral/cushioned versus minimalist (5 studies, 766 participants) Neutral/cushioned shoes may make little or no difference to the number of runners sustaining a lower-limb running injuries when compared with minimalist shoes (low-certainty evidence) (risk ratio (RR) 0.77, 95% confidence interval (CI) 0.59 to 1.01). One trial reported that 67% and 92% of runners were satisfied with their neutral/cushioned or minimalist running shoes, respectively (RR 0.73, 95% CI 0.47 to 1.12). Another trial reported mean satisfaction scores ranged from 4.0 to 4.3 in the neutral/ cushioned group and 3.6 to 3.9 in the minimalist running shoe group out of a total of 5. Hence neutral/cushioned running shoes may make little or no difference to runner satisfaction with footwear (low-certainty evidence). Motion control versus neutral / cushioned (2 studies, 421 participants) It is uncertain whether or not motion control shoes reduce the number of runners sustaining a lower-limb running injuries when compared with neutral / cushioned shoes because the quality of the evidence has been assessed as very low certainty (RR 0.92, 95% CI 0.30 to 2.81). Soft midsole versus hard midsole (2 studies, 1095 participants) Soft midsole shoes may make little or no difference to the number of runners sustaining a lower-limb running injuries when compared with hard midsole shoes (low-certainty of evidence) (RR 0.82, 95% CI 0.61 to 1.10). Stability versus neutral / cushioned (1 study, 57 participants) It is uncertain whether or not stability shoes reduce the number of runners sustaining a lower-limb running injuries when compared with neutral/cushioned shoes because the quality of the evidence has been assessed as very low certainty (RR 0.49, 95% CI 0.18 to 1.31). Motion control versus stability (1 study, 56 participants) It is uncertain whether or not motion control shoes reduce the number of runners sustaining a lower-limb running injuries when compared with stability shoes because the quality of the evidence has been assessed as very low certainty (RR 3.47, 95% CI 1.43 to 8.40). Running shoes prescribed and selected on foot posture (3 studies, 7203 participants) There was no evidence that running shoes prescribed based on static foot posture reduced the number of injuries compared with those who received a shoe not prescribed based on foot posture in military recruits (Rate Ratio 1.03, 95% CI 0.94 to 1.13). Subgroup analysis confirmed these findings were consistent between males and females. Therefore, prescribing running shoes and selecting on foot posture probably makes little or no difference to lower-limb running injuries (moderate-certainty evidence). Data were not available for all other review outcomes.

AUTHORS' CONCLUSIONS

Most evidence demonstrates no reduction in lower-limb running injuries in adults when comparing different types of running shoes. Overall, the certainty of the evidence determining whether different types of running shoes influence running injury rates was very low to low, and as such we are uncertain as to the true effects of different types of running shoes upon injury rates. There is no evidence that prescribing footwear based on foot type reduces running-related lower-limb injures in adults. The evidence for this comparison was rated as moderate and as such we can have more certainty when interpreting these findings. However, all three trials included in this comparison used military populations and as such the findings may differ in recreational runners.  Future researchers should develop a consensus definition of running shoe design to help standardise classification. The definition of a running injury should also be used consistently and confirmed via health practitioners. More researchers should consider a RCT design to increase the evidence in this area. Lastly, future work should look to explore the influence of different types or running shoes upon injury rates in specific subgroups.

Effect of the Innovative Running Shoes With the Special Midsole Structure on the Female Runners’ Lower Limb Biomechanics

The study aimed to research the effects of innovative running shoes (a high heel-to-toe drop and special structure of midsole) on the biomechanics of the lower limbs and perceptual sensitivity in female runners. Fifteen healthy female runners were recruited to run through a 145-m runway with planted force plates at one peculiar speed (3.6 m/s ± 5%) with two kinds of shoe conditions (innovative running shoes vs. normal running shoes) while getting biomechanical data. The perception of shoe characteristics was assessed simultaneously through a 15-cm visual analog scale. The statistical parametric mapping technique calculated the time-series parameters. Regarding 0D parameters, the ankle dorsiflexion angle of innovative running shoes at touchdown was higher, and the peak dorsiflexion angle, range of motion, peak dorsiflexion velocity, and plantarflexion moment on the metatarsophalangeal joint of innovative running shoes during running were significantly smaller than those of normal running shoes (all p < 0.001). In addition, the braking phase and the time of peak vertical force 1 of innovative running shoes were found to be longer than those of normal running shoes (both p < 0.05). Meanwhile, the average vertical loading rate 1, peak vertical loading rate 1, peak braking force, and peak vertical force 1 in the innovative running shoes were lower than those of the normal running shoes during running (both p < 0.01). The statistical parametric mapping analysis exhibited a higher ankle dorsiflexion angle (0–4%, p < 0.05), a smaller knee internal rotation angle (0–6%, p < 0.05) (63–72%, p < 0.05), a decreased vertical ground reaction force (11–17%, p = 0.009), and braking anteroposterior ground reaction force (22–27%, p = 0.043) for innovative running shoes than normal running shoes. Runners were able to perceive the cushioning of innovative running shoes was better than that of normal running shoes. These findings suggested combining the high offset and structure of the midsole would benefit the industrial utilization of shoe producers in light of reducing the risk of running injuries for female runners.

Evaluation and optimisation of a footwear assessment tool for use within a clinical environment

Footwear has been documented as a significant factor in the aetiology of foot pain in the general population. Assessing footwear in a clinical setting continues to be practitioner specific and there is limited guidance to direct advice. Health professionals must have access to clinically appropriate and reliable footwear assessment tools to educate patients on healthier footwear choices. The primary aim of this study was to critique what elements should be in a footwear assessment tool with a secondary aim of testing the agreed tool for validity.

A combined Nominal Group Technique and then a Delphi technique from purposively sampled experts of foot health professions were employed to critique elements of footwear assessment. The agreed tool was then tested by practising podiatrists on 5 different shoes to assess the validity and reliability of the measures.

Twelve test evaluation criteria were identified receiving significant ratings to form the final footwear assessment tool consisting of five footwear themes. Application of the tool in a clinical setting validated the themes of footwear characteristics, footwear structure, motion control and wear patterns. However, the assessment of footwear fit was not reliable.

The footwear tool was refined based on the collective consensus achieved from the rounds creating a more clinically appropriate tool. The validity of this tool was assessed as high in some of the themes but for those that were lower, a training need was identified.

Effects of Running on Sand vs. Stable Ground on Kinetics and Muscle Activities in Individuals With Over-Pronated Feet

Background: In terms of physiological and biomechanical characteristics, over-pronation of the feet has been associated with distinct muscle recruitment patterns and ground reaction forces during running.

Objective: The aim of this study was to evaluate the effects of running on sand vs. stable ground on ground-reaction-forces (GRFs) and electromyographic (EMG) activity of lower limb muscles in individuals with over-pronated feet (OPF) compared with healthy controls.

Methods: Thirty-three OPF individuals and 33 controls ran at preferred speed and in randomized-order over level-ground and sand. A force-plate was embedded in an 18-m runway to collect GRFs. Muscle activities were recorded using an EMG-system. Data were adjusted for surface-related differences in running speed.

Results: Running on sand resulted in lower speed compared with stable ground running (p < 0.001; d = 0.83). Results demonstrated that running on sand produced higher tibialis anterior activity (p = 0.024; d = 0.28). Also, findings indicated larger loading rates (p = 0.004; d = 0.72) and greater vastus medialis (p < 0.001; d = 0.89) and rectus femoris (p = 0.001; d = 0.61) activities in OPF individuals. Controls but not OPF showed significantly lower gluteus-medius activity (p = 0.022; d = 0.63) when running on sand.

Conclusion: Running on sand resulted in lower running speed and higher tibialis anterior activity during the loading phase. This may indicate alterations in neuromuscular demands in the distal part of the lower limbs when running on sand. In OPF individuals, higher loading rates together with greater quadriceps activity may constitute a proximal compensatory mechanism for distal surface instability.

Effects of nail softness and stiffness with distance running shoes on ground reaction forces and vertical loading rates in male elite long-distance runners with pronated feet

BACKGROUND

To improve propulsion during running, athletes often wear spike shoes designed for training and/or competition. Running with spike shoes may cause pain and/or injuries. To address this problem, a modified spike shoe was tested. This study aimed to evaluate the effects of running with dual-versus single-stiffness spike running shoes on running mechanics in long-distance runners with pronated feet.

METHODS

Sixteen male elite (national competitive level) runners (5000 or 10,000 m) aged 28.2 ± 2.5 years with pronated feet volunteered to participate in this study. To be included, participants had to have achieved personal best race times over 5- and/or 10-km races under 17 or 34 min during official running competitions. All participants were heel strikers and had a history of 11.2 ± 4.2 years of training. For the assessment of running kinetics, a force plate was imbedded into a walkway. Running kinematics were recorded using a Vicon-motion-capture system. Nike Zoom Rival shoes (Nike, Nike Zoom Rival, USA) were selected and adapted according to spike softness and stiffness. Participants ran at a constant speed of ~4.0 m/s across the walkway with both shoe conditions in randomized order. Six trials were recorded per condition. The main outcomes included peak ground reaction forces and their time-to-peak, average and instantaneous vertical loading rates, free moments, and peak ankle eversion angles.

RESULTS

Paired t-tests revealed significantly lower lateral (p = 0.021, d = 0.95) and vertical (p = 0.010, d = 1.40) forces at heel contact during running with dual-stiffness spike shoes. Running with dual-stiffness spike shoes resulted in a significantly longer time-to-peak vertical (p = 0.004, d = 1.40) force at heel contact. The analysis revealed significantly lower average (p = 0.005, d = 0.46) and instantaneous (p = 0.021, d = 0.49) loading rates and peak negative free moment amplitudes (p = 0.016, d = 0.81) when running with dual-stiffness spike shoes. Finally, significantly lower peak ankle eversion angles were observed with dual-stiffness spike shoes (p < 0.001, d = 1.29).

CONCLUSIONS

Running in dual- compared with single-stiffness spike distance running shoes resulted in lower loading rates, free moment amplitudes, and peak ankle eversion angles of long-distance runners with pronated feet.

A síndrome da dor patelofemoral altera o movimento do retropé, mas não modifica a distribuição da pressão plantar

Objective  To compare the plantar pressure distribution and the kinematics of the rearfoot on the stance phase of subjects with or without patellofemoral pain syndrome (PFPS).

Methods  A total of 26 subjects with PFPS and 31 clinically healthy subjects, who were paired regarding age, height and mass, participated in the study. The plantar pressure distribution (peak pressure) was assessed in six plantar regions, as well as the kinematics of the rearfoot (maximum eversion angle, percentage of the stance phase when the maximum angle was reached, and percentage of the stance phase in which the rearfoot was in eversion). The data were analyzed by descriptive and inferential statistics, with a significance level of p  ≤ 0.05.

Results  The pressure on the six plantar regions analyzed and the magnitude of the maximum eversion angle of the rearfoot when walking on flat surfaces did not present differences among the subjects with PFPS. However, the PFPS subjects showed, when walking, an earlier maximum eversion angle of the rearfoot than the subjects on the control group, and stayed less time with the rearfoot in eversion.

Conclusion  The PFPS seems to be related to modifications on the temporal pattern on the kinematics of the rearfoot.

Controlled trial to compare the Achilles tendon load during running in flatfeet participants using a customized arch support orthoses vs an orthotic heel lift

Background

Achilles tendinopathy is one of the most common overuse injuries in running, and forefoot pronation, seen in flatfeet participants, has been proposed to cause additional loading across the Achilles tendon. Foot orthoses are one of the common and effective conservative treatment prescribed for Achilles tendinopathy, it works by correcting the biomechanical malalignment and reducing tendon load. Previous studies have shown reduction of Achilles Tendon load (ATL) during running by using customized arch support orthosis (CASO) or an orthotic heel lift (HL). However, there are still little biomechanical evidence and comparative studies to guide orthotic prescriptions for Achilles tendinopathy management. Therefore, this study seeks to investigate the two currently employed orthotic treatment options for Achilles tendinopathy: CASO and HL for the reduction of ATL and Achilles tendon loading rate (ATLR) in recreational runners with flatfeet.

Methods

Twelve participants were recruited and run along the runway in the laboratory for three conditions: (1) without orthoses, (2) with CASO (3) with HL. Kinematic and kinetic data were recorded by 3D motion capturing system and force platform. Ankle joint moments and ATL were computed and compared within the three conditions.

Results

Participants who ran with CASO (p = 0.001, d = 0.43) or HL (p = 0.001, d = 0.48) associated with a significant reduction in ATL when compared to without orthotics while there was no significant difference between the two types of orthoses, the mean peak ATL of CASO was slightly lower than HL. Regarding the ATLR, both orthoses, CASO (p = 0.003, d = 0.93) and HL (p = 0.004, d = 0.78), exhibited significant lower value than the control but similarly, no significant difference was noted between them in which the use of CASO yielded a slightly lower loading rate than that of HL.

Conclusions

Both CASO and HL were able to cause a significant reduction in peak ATL and ATLR comparing to without orthotics condition. There were subtle but no statistically significant differences in the biomechanical effects between the two types of orthoses. The findings help to quantify the effect of CASO and HL on load reduction of Achilles tendon and suggests that foot orthoses may serve to prevent the incidence of Achilles tendon pathologies.

Trial registration

NCT04003870 on clinicaltrials.gov 1 July 2019.

Relationships between the foot posture Index and static as well as dynamic rear foot and arch variables

Clinicians, podiatrists and researchers have been quantifying foot posture and movement in various speed conditions and populations. Common variables to assess foot posture/movement are the Foot Posture Index (FPI-6), Achilles tendon angle (β), rear foot angle (γ) and longitudinal arch angle (LAA). These variables were frequently used in clinical and biomechanical settings. This study aimed to determine the relationship between the biomechanical variables (β, γ & LAA) in static and dynamic conditions and the clinically used FPI-6 and their redundancy. Forty participants performed bipedal standing, over ground walking and running trials. Manual assessment data (FPI-6), kinematic data and ground reaction forces were collected. Discrete biomechanical variables (β, γ & LAA) were calculated at various time points (e.g. heel strike). A Principal Component Analysis (PCA) was performed to quantify the contribution of each variable to the overall variance in the data set. Spearman correlations were used to assess the relationship between the sub-measures of the FPI-6 and the biomechanical variables. Two major components were found that explained 85.2% of the overall variance, consisting of LAA and β variables, respectively. Only LAA variables showed significant, but moderate correlations (r < -0.6) with the fifth sub-measurement of the FPI-6. The LAA and β describe independent movements, which dominate foot posture/movement in static and dynamic conditions. The FPI-6 sub-measurements did not closely reflect static nor dynamic behavior of the rear and mid foot. The FPI-6 and biomechanical variables may not be used interchangeably for screening or grouping individuals according to their foot posture/movement.

Motion-control shoes help maintaining low loading rate levels during fatiguing running in pronated female runners

BACKGROUND

The use of motion-control shoes may assist pronated runners to maintain their stability throughout a fatiguing running. However, there are no studies describing the effects of fatigue on running biomechanics of runners with pronated feet.

RESEARCH QUESTION

Whether motion-control shoes can assist pronated recreational female runners to maintain impact loading patterns following a fatiguing protocol?

METHODS

Twenty-two female rearfoot runners with foot pronation were asked to perform a fatiguing treadmill running protocol using a neutral shoe or a motion-control shoe in two separate occasions. Before (Pre-fatigue) and after the fatiguing protocol (Post-fatigue), participants were asked to run overground on a track that contained two force platforms to record ground reaction forces and moments. Running speed were 3.3 m s^-1 (±2.5% variability). The effects of shoe type and fatigue were investigated on the peak vertical impact ground reaction force (pvIGRF), time to reach pvIGRF, vertical loading rate (LR) and peak negative foot free moments (FM).

RESULTS

Pronated runners presented lower LR with motion-control shoes compared to neutral shoes Pre- (p < 0.005; -18 ± 25%) and Post-fatigue (p < 0.001; -27 ± 15%). This change in LR was predominantly driven by a longer time to reach pvIGRF with motion-control shoes (p < 0.001, 39%). The pvIGRF and LR increased after fatiguing running with neutral shoes (pvIGRF: p < 0.05; 18 ± 28%; LR: p < 0.05; 15 ± 22%), but not with motion-control shoes. Furthermore, there were strong correlations between FM and LR for both Pre-fatigue (r=-0.61, p < 0.005) and Post-fatigue measurements (r=-0.66, p < 0.01), but only for the motion-control shoes.

SIGNIFICANCE

These results suggest that motion-control shoes prevent exacerbated fatigue-related increases in mechanical loading following initial contact in pronated female runners.

The Influence of Motion Control, Neutral, and Cushioned Running Shoes on Lower Limb Kinematics

To date there is a paucity of information about how different types of conventional running shoes influence lower limb kinematics. The aim of the study was to determine the influence of motion control, neutral, and cushioned running shoes upon lower limb kinematics. Twenty-eight active males completed one test session running in standardized motion control, neutral, and cushioned running shoes on a treadmill at a self-selected pace (2.9 [0.6] m·s^-1). Kinematic data were collected using a VICON motion analysis system with hip, knee, and ankle joint angles calculated. Discrete parameters associated with stance phase kinematics were compared between footwear conditions. Significant (P < .05) differences in knee flexion and internal rotation at toe off, and knee adduction range of motion were reported between footwear conditions. Significant (P < .05) differences in ankle joint dorsiflexion and adduction upon initial contact, peak dorsiflexion, eversion and abduction, and inversion at toe off were reported between footwear conditions. The influence of motion control, neutral, and cushioned running shoes on joint function dissipates moving proximally, with larger changes reported at the ankle compared with knee and hip joints. Although significant differences were reported between footwear conditions, these changes were of a small magnitude and effect size.

Effects of anti-pronation shoes on lower limb kinematics and kinetics in female runners with pronated feet: The role of physical fatigue

Physical fatigue and pronated feet constitute two risk factors for running-related lower limb injuries. Accordingly, different running shoe companies designed anti-pronation shoes with medial support to limit over pronation in runners. However, there is little evidence on the effectiveness and clinical relevance of anti-pronation shoes. This study examined lower limb kinematics and kinetics in young female runners with pronated feet during running with anti-pronation versus regular (neutral) running shoes in unfatigued and fatigued condition. Twenty-six female runners aged 24.1±5.6 years with pronated feet volunteered to participate in this study. Kinetic (3D Kistler force plate) and kinematic analyses (Vicon motion analysis system) were conducted to record participants’ ground reaction forces and joint kinematics when running with anti-pronation compared with neutral running shoes. Physical fatigue was induced through an individualized submaximal running protocol on a motorized treadmill using rate of perceived exertion and heart rate monitoring. The statistical analyses indicated significant main effects of “footwear” for peak ankle inversion, peak ankle eversion, and peak hip internal rotation angles (p<0.03; d = 0.46–0.95). Pair-wise comparisons revealed a significantly greater peak ankle inversion angle (p<0.03; d = 0.95; 2.70°) and smaller peak eversion angle (p<0.03; d = 0.46; 2.53°) when running with anti-pronation shoes compared with neutral shoes. For kinetic data, significant main effects of “footwear” were found for peak ankle dorsiflexor moment, peak knee extensor moment, peak hip flexor moment, peak hip extensor moment, peak hip abductor moment, and peak hip internal rotator moment (p<0.02; d = 1.00–1.79). For peak positive hip power in sagittal and frontal planes and peak negative hip power in horizontal plane, we observed significant main effects of “footwear” (p<0.03; d = 0.92–1.06). Pairwise comparisons revealed that peak positive hip power in sagittal plane (p<0.03; d = 0.98; 2.39 w/kg), peak positive hip power in frontal plane (p = 0.014; d = 1.06; 0.54 w/kg), and peak negative hip power in horizontal plane (p<0.03; d = 0.92; 0.43 w/kg) were greater with anti-pronation shoes. Furthermore, the statistical analyses indicated significant main effects of “Fatigue” for peak ankle inversion, peak ankle eversion, and peak knee external rotation angles. Pair-wise comparisons revealed a fatigue-induced decrease in peak ankle inversion angle (p<0.01; d = 1.23; 2.69°) and a fatigue-induced increase in peak knee external rotation angle (p<0.05; d = 0.83; 5.40°). In addition, a fatigue-related increase was found for peak ankle eversion (p<0.01; d = 1.24; 2.67°). For kinetic data, we observed a significant main effect of “Fatigue” for knee flexor moment, knee internal rotator moment, and hip extensor moment (p<0.05; d = 0.83–1.01). The statistical analyses indicated significant a main effect of “Fatigue” for peak negative ankle power in sagittal plane (p<0.01; d = 1.25). Finally, we could not detect any significant footwear by fatigue interaction effects for all measures of joint kinetics and kinematics. Running in anti-pronation compared with neutral running shoes produced lower peak moments and powers in lower limb joints and better control in rear foot eversion. Physical fatigue increased peak moments and powers in lower limb joints irrespective of the type of footwear.

Comparative Evaluation of Radiographic Parameters of Foot Pronation in Two Different Conditions versus Barefoot

BACKGROUND

To date, there is conflicting evidence that high-end "motion control" running shoes can correct and control rearfoot pronation. Many methods have been used to evaluate the efficacy of motion control footwear in reducing hindfoot pronation during gait, including stop-motion photography, three-dimensional camera kinematic analysis, and three-dimensional bone modeling using computed tomography. Until now, there have been no radiographic studies that examined the effect of motion control running shoes on the static posture of the foot. Murley et al devised a reliable system that correlated noninvasive clinical examinations to radiographic values that correspond to foot pronation. The aim of this prospective investigation was to determine whether motion control running shoes are able to produce a significant difference in pronation through a radiographic study, using the angular relationships as described by Murley et al, in two different shoe conditions as compared to the barefoot condition in female subjects.

METHODS

This prospective study screened 28 female subjects ranging in age from 22 to 27 years on the basis of arch height index. The 24 subjects with a standing arch height index less than 0.370 were invited to participate in the study. Unilateral weightbearing dorsoplantar and lateral foot radiographs were taken in barefoot, neutral shoe, and motion control shoe conditions. Calcaneal inclination angle, calcaneal-first metatarsal (CFMA) angle, talonavicular coverage angle (TNCA), and talus-second metatarsal angle were measured in each condition by two independent observers using the Opal-Ortho PACS software package and then averaged. Angles were compared to barefoot baseline values using paired t tests.

RESULTS

The motion control running shoe produced average decreases of 2.64% in CFMA, 12.62% in TNCA, 5.3% in talus-second metatarsal angle and an average increase of 1.3% in calcaneal inclination angle. Statistically significant ( P > .05) improvements in CFMA were noted in both the motion control ( P < .000) and neutral shoe conditions ( P < .000) when compared to barefoot, whereas TNCA improved only in the motion control shoe condition as compared to barefoot ( P = .003).

CONCLUSIONS

This investigation found evidence that the particular models of motion control running shoes studied could correct foot pronation in the transverse and sagittal planes in stance. Motion control running shoes improved CFMA and TNCA from the barefoot condition and were more effective in correcting pronation compared with neutral running shoes in this radiographic study simulating static foot posture in stance.

Effects of Slipper Features and Properties on Walking and Sit-to-Stand Tasks of Older Women

Indoor slippers with a strap across the dorsal forefoot are popular with older women. However, their influence on the foot motion has not been reported. This study evaluated the range of movement in the knee and ankle joints during walking and changes in trunk displacement during sit-to-stand when 10 healthy older women wore two types of slippers and were barefoot. Compared to barefeet, walking in slippers results in significant increases in the knee flexion angle in the swing phase. However, there is nonsignificant differences in the ankle angle in any phase across all conditions. During the sit-stand transition when slippers are worn, there is a significant reduction in the peak trunk tilt angle and range, as well as the duration of the weight shift when motion is initiated. The findings therefore provide a better understanding of slipper features and designs associated with changes in foot kinematics in older women.

Relationship between foot eversion and thermographic foot skin temperature after running

The main instruments to assess foot eversion have some limitations (especially for field applications), and therefore it is necessary to explore new methods. The objective was to determine the relationship between foot eversion and skin temperature asymmetry of the foot sole (difference between medial and lateral side), using infrared thermography. Twenty-two runners performed a running test lasting 30 min. Skin temperature of the feet soles was measured by infrared thermography before and after running. Foot eversion during running was measured by kinematic analysis. Immediately after running, weak negative correlations were observed between thermal symmetry of the rearfoot and eversion at contact time, and between thermal symmetry of the entire plantar surface of the foot and maximum eversion during stance phase (r=-0.3 and p=0.04 in both cases). Regarding temperature variations, weak correlations were also observed (r=0.4 and p<0.05). The weak correlations observed in this study suggest that skin temperature is not related to foot eversion. However, these results open interesting future lines of research.

Effects of running-induced fatigue on plantar pressure distribution in novice runners with different foot types

This study aimed to assess the effects of running-induced fatigue on plantar pressure parameters in novice runners with low and high medial longitudinal arch. Plantar pressure data from 42 novice runners (21 with high, and 21 with low arch) were collected before and after running-induced fatigue protocol during running at 3.3m/s along the Footscan(®) platform. Peak plantar pressure, peak force and force-time integral (impulse) were measured in ten anatomical zones. Relative time for foot roll-over phases and medio-lateral force ratio were calculated before and after the fatigue protocol. After the fatigue protocol, increases in the peak pressure under the first-third metatarsal zones and reduction under the fourth-fifth metatarsal regions were observed in the low arch individuals. In the high arch group, increases in peak pressure under the fourth-fifth metatarsal zones after the running-induced fatigue was observed. It could be concluded that running-induced fatigue had different effects on plantar pressure distribution pattern among novice runners with low and high medial longitudinal foot arch. These findings could provide some information related to several running injuries among individuals with different foot types.

Neuro-mechanical adjustments to shod versus barefoot treadmill runs in the acute and delayed stretch-shortening cycle recovery phases

In habitually shod recreational runners, we studied the combined influence of footwear and stretch-shortening cycle (SSC) fatigue on treadmill running pattern, paying special attention to neuro-mechanical adjustments in the acute and 2-day delayed recovery periods. The SSC exercise consisted of a series of 25 sub-maximal rebounds on a sledge apparatus repeated until exhaustion. The acute and delayed functional fatigue effects were quantified in a maximal drop jump test. The neuro-mechanical adjustments to fatigue were examined during two submaximal treadmill run tests of 3 min performed either barefoot or with shoes on. Surface electromyographic (EMG) activities, tibial accelerations and kinematics of the right lower limb were recorded during the first and last 15 s of each run. The main result was that neuro-mechanical differences between the shod and barefoot running patterns, classically reported in the absence of fatigue, persisted in the fatigued state. However, in the delayed recovery phase, rearfoot eversion was found to significantly increase in the shod condition. This specific footwear effect is considered as a potential risk factor of overuse injuries in longer runs. Therefore, specific care should be addressed in the delayed recovery phase of SSC fatigue and the use of motion control shoes could be of interest.

Running with a minimalist shoe increases plantar pressure in the forefoot region of healthy female runners

OBJECTIVES

Minimalist running shoes have been proposed as an alternative to barefoot running. However, several studies have reported cases of forefoot stress fractures after switching from standard to minimalist shoes. Therefore, the aim of the current study was to investigate the differences in plantar pressure in the forefoot region between running with a minimalist shoe and running with a standard shoe in healthy female runners during overground running.

DESIGN

Randomized crossover design.

METHODS

In-shoe plantar pressure measurements were recorded from eighteen healthy female runners. Peak pressure, maximum mean pressure, pressure time integral and instant of peak pressure were assessed for seven foot areas. Force time integral, stride time, stance time, swing time, shoe comfort and landing type were assessed for both shoe types. A linear mixed model was used to analyze the data.

RESULTS

Peak pressure and maximum mean pressure were higher in the medial forefoot (respectively 13.5% and 7.46%), central forefoot (respectively 37.5% and 29.2%) and lateral forefoot (respectively 37.9% and 20.4%) for the minimalist shoe condition. Stance time was reduced with 3.81%. No relevant differences in shoe comfort or landing strategy were found.

CONCLUSIONS

Running with a minimalist shoe increased plantar pressure without a change in landing pattern. This increased pressure in the forefoot region might play a role in the occurrence of metatarsal stress fractures in runners who switched to minimalist shoes and warrants a cautious approach to transitioning to minimalist shoe use.

Kinematic changes during running-induced fatigue and relations with core endurance in novice runners

OBJECTIVES

This study aimed to investigate kinematic changes experienced during running-induced fatigue. Further, the study examined relations between kinematic changes and core endurance.

DESIGN

Repeated measures and correlation.

METHODS

Seventeen novice runners participated in a running-induced fatigue protocol and underwent core endurance assessment. Participants ran at a steady state corresponding to an intensity of 13 on the Borg scale and continued until 2min after a Borg score of 17 or 90% of maximum heart rate was reached. Kinematic data were analyzed for the lower extremities and trunk throughout a running protocol and, on separate days, core endurance measures were recorded. Changes in pre- and post-fatigue running kinematics and their relations with core endurance measures were analyzed.

RESULTS

Analysis of peak joint angles revealed significant increases in trunk flexion (4°), decreases in trunk extension (3°), and increases in non-dominant ankle eversion (1.6°) as a result of running-induced fatigue. Post-fatigue increased trunk flexion changes displayed a strong to moderate positive relation with trunk extensor core endurance measures, in contrast to expected negative relations.

CONCLUSIONS

Novice runners displayed an overall increase in trunk inclination and increased ankle eversion peak angles when fatigued utilizing a running-induced fatigue protocol. As most pronounced changes were found for the trunk, trunk kinematics appear to be significantly affected during fatigued running and should not be overlooked. Core endurance measures displayed unexpected relations with running kinematics and require further investigation to determine the significance of these relations.

The influence of motion control shoes on the running gait of mature and young females

BACKGROUND

This study compared the running gait of mature and young females, and investigated the effect of a motion control shoe. First, it was hypothesised that in a neutral shoe, mature females would display significantly greater rearfoot eversion, knee internal rotation and external adductor moments when compared to a younger group. Secondly, the motion control shoe would reduce rearfoot eversion and knee internal rotation in both groups. Thirdly it was hypothesised that the motion control shoe would increase knee external adductor moment, through an increase in knee varus and moment arm.

METHODS

15 mature (40-60 years) and 15 young (18-25 years) females performed 10 running trials at 3.5ms(-1)±5% over a force platform. Two shoes were tested, the Adidas Supernova Glide (neutral), and the Adidas Supernova Sequence (motion control). Ankle and knee joint dynamics were analysed for the right leg, and the mean of ten trials was calculated. Joint moments were calculated using inverse dynamics.

FINDINGS

In the neutral condition, mature females presented greater peak rearfoot eversion, knee internal rotation, and external adductor moments than young females (p<0.05). A motion control shoe significantly reduced peak rearfoot eversion and knee internal rotation among both groups (p<0.05). No between shoe differences in knee external adductor moment were observed.

INTERPRETATION

A motion control shoe is recommended to reduce risk of injury associated with rearfoot eversion and knee internal rotation in mature females. However since the knee external adductor moment is a variable commonly associated with medial knee loading it is suggested that alternative design features are required to influence this moment.

Suspected mechanisms in the cause of overuse running injuries: a clinical review

Context:

Various epidemiological studies have estimated that up to 70% of runners sustain an overuse running injury each year. Although few overuse running injuries have an established cause, more than 80% of running-related injuries occur at or below the knee, which suggests that some common mechanisms may be at work. The question then becomes, are there common mechanisms related to overuse running injuries?

Evidence Acquisition:

Research studies were identified via the following electronic databases: MEDLINE, EMBASE PsycInfo, and CINAHL (1980–July 2008). Inclusion was based on evaluation of risk factors for overuse running injuries.

Results:

A majority of the risk factors that have been researched over the past few years can be generally categorized into 2 groups: atypical foot pronation mechanics and inadequate hip muscle stabilization.

Conclusion:

Based on the review of literature, there is no definitive link between atypical foot mechanics and running injury mechanisms. The lack of normative data and a definition of typical foot structure has hampered progress. In contrast, a large and growing body of literature suggests that weakness of hip-stabilizing muscles leads to atypical lower extremity mechanics and increased forces within the lower extremity while running.

Effects of motion control footwear on running: a systematic review

Excessive foot pronation is a risk factor of running injuries and motion control footwear is designed to control foot pronation. With the movement transfer between foot pronation and tibial rotation, motion control footwear may not only be confined to controlling foot pronation. In view of the controversies in the literature on effectiveness of motion control footwear, this paper reviewed the efficacy of motion control footwear functions as reported in the literature. Eligible studies were identified from seven electronic databases. Two independent authors extracted the data and assessed the methodological qualities using the Jadad Scale. A total of 14 quasi randomised controlled trials were included. Even though the included studies were rated as "low quality" according to the Jadad Scale, the data were pooled and analysed. Results revealed that motion control footwear was effective in reducing the amount of foot pronation and the peak vertical impact during landing. There is no evidence that suggests motion control footwear for controlling kinematics of the proximal segments.

Changes in joint coupling and variability during walking following tibialis posterior muscle fatigue

Background

The tibialis posterior muscle is believed to play a key role in controlling foot mechanics during the stance phase of gait. However, an experiment involving localised tibialis posterior muscle fatigue, and analysis of discrete rearfoot and forefoot kinematic variables, indicated that reduced force output of the tibialis posterior muscle did not alter rearfoot and forefoot motion during gait. Thus, to better understand how muscle fatigue affects foot kinematics and injury potential, the purpose of this study was to reanalyze the data and investigate shank, rearfoot and forefoot joint coupling and coupling variability during walking.

Methods

Twenty-nine participants underwent an exercise fatigue protocol aimed at reducing the force output of tibialis posterior. An eight camera motion analysis system was used to evaluate 3 D shank and foot joint coupling and coupling variability during treadmill walking both pre- and post-fatigue.

Results

The fatigue protocol was successful in reducing the maximal isometric force by over 30% and a concomitant increase in coupling motion of the shank in the transverse plane and forefoot in the sagittal and transverse planes relative to frontal plane motion of the rearfoot. In addition, an increase in joint coupling variability was measured between the shank and rearfoot and between the rearfoot and forefoot during the fatigue condition.

Conclusions

The reduced function of the tibialis posterior muscle following fatigue resulted in a disruption in typical shank and foot joint coupling patterns and an increased variability in joint coupling. These results could help explain tibialis posterior injury aetiology.

The role of tibialis posterior fatigue on foot kinematics during walking

Background

The purpose of this study was to investigate the effect of localised tibialis posterior muscle fatigue on foot kinematics during walking. It was hypothesised that following fatigue, subjects would demonstrate greater forefoot and rearfoot motion during walking. It was also postulated that the magnitude of the change in rearfoot motion would be associated with standing anatomical rearfoot posture.

Methods

Twenty-nine subjects underwent an exercise fatigue protocol aimed at reducing the force output of tibialis posterior. An eight camera motion analysis system was used to evaluate 3D foot kinematics during treadmill walking both pre- and post-fatigue. The anatomical rearfoot angle was measured during standing prior to the fatigue protocol using a goniometer.

Results

Peak rearfoot eversion remained unchanged following the fatigue protocol. Although increases in rearfoot eversion excursion were observed following fatigue, these changes were of a magnitude of questionable clinical significance (<1.0°). The magnitude of the change in rearfoot eversion due to fatigue was not associated with the anatomical measurement of standing rearfoot angle. No substantial changes in forefoot kinematics were observed following the fatigue protocol.

Conclusions

These data indicate that reduced force output of the tibialis posterior muscle did not alter rearfoot and forefoot motion during gait. The anatomical structure of the rearfoot was not associated with the dependence of muscular activity that an individual requires to maintain normal rearfoot kinematics during gait.

Motion control shoe delays fatigue of shank muscles in runners with overpronating feet

BACKGROUND

The motion control shoe is a well-developed technology in running shoe design for controlling excessive rearfoot pronation and plantar force distribution. However, there is little information on the leg muscle activation with different shoe conditions.

HYPOTHESIS

The motion control shoe can prevent excessive shank muscle activation and delay fatigue.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty female recreational runners with excessive rearfoot pronation were tested with running 10 km on a treadmill on 2 days. Participants wore either a motion control running shoe or neutral running shoe on each day. Activities of their right tibialis anterior and peroneus longus were recorded with surface electromyography. The normalized root-mean-square electromyography and median frequency were compared between the 2 shoe conditions.

RESULTS

Significant positive correlations were found between the root-mean-square eletromyography and running mileage in both the tibialis anterior and peroneus longus in the neutral shoe condition (P <.001). The median frequency dropped in both shoe conditions with mileage, but paired t tests revealed a significantly larger drop in the neutral shoe (P < .001 for peroneus longus, P = .074 for tibialis anterior).

CONCLUSION

The motion control shoe may facilitate a more stable activation pattern and higher fatigue resistance of the tibialis anterior and peroneus longus in individuals with excessive rearfoot pronation during running.

CLINICAL RELEVANCE

The motion control shoe may increase the running endurance, thus reduce overuse injuries, in athletes with unstable feet during long-distance running.

Influence of different footwear on force of landing during running

BACKGROUND AND PURPOSE

Previous studies have demonstrated an increase in foot pronation with mileage in runners. Motion control footwear was designed to check excessive foot motions, but its clinical efficacy, especially in terms of pedographic analysis, has not been well reported. The purposes of this study were to investigate the changes in plantar force in people when running with motion control shoes and to compare pedographic measurements obtained in 2 footwear testing conditions (wearing motion control shoes and wearing neutral shoes) at the beginning and end of a 1.5-km running session.

SUBJECTS

Twenty-five recreational runners who had > or = 6 degrees of foot pronation participated in the study.

METHODS

An insole sensor was used to register the plantar force of the subjects before and after running 1.5 km in different shoe conditions.

RESULTS

There was no change in the magnitude and distribution pattern of plantar force with the motion control shoes after the 1.5-km run. With the neutral shoes, however, there was an increase in mean peak force under the medial midfoot (364-418 N, 15% increase) and first metatarsal head (524-565 N, 8% increase) toward the end of the running bout.

DISCUSSION AND CONCLUSION

The plantar force on the medial foot structures increased with mileage of running with neutral shoes but not with motion control shoes. This finding has implications for injury prevention with footwear selection for recreational runners who have more than 6 degrees of foot pronation.