Does an acute transition to different footwear conditions affect walking patterns in people with different experiences of minimalist footwear?

BACKGROUND

Minimalistic footwear provides adequate toe space, tripod function, improving foot function, muscle activation and stability during walking similarly to barefoot walking. Due to the increasing popularity of this specific footwear, there is a lack of research focusing on general users of minimalistic footwear.

RESEARCH QUESTION

Does annual walking in minimalistic footwear affect gait biomechanics?

METHODS

Cross-sectional study involving twenty participants in a minimalistic footwear group with both experience (MFE) and no experience (NMFE). Participants walked in three different conditions (barefoot, minimalistic, and neutral footwear) in the laboratory at normal human walking speed.

RESULTS

A significant main effect of groups regardless of footwear conditions show significantly greater values during walking in minimalistic footwear and barefoot in the stride length (p=0.035, p=0.003, respectively), and stride width (p=0.047, p=0.028, respectively) in the NMFE group compared to MFE group. The significant differences in the main effects of footwear regardless of experience were found in stance time (p<0.001), steps per minute (p<0.001), stride length (<0.001), foot adduction in TO (p<0.001), foot eversion angle in IC and TO (p<0.001, p<0.001, respectively), foot progression angle (p<0.001), ankle dorsiflexion angle in IC and TO (p<0.001, p<0.001, respectively), in ankle eversion angle in IC and TO (p<0.001, p<0.001, respectively), knee flexion angle in IC and TO (p<0.001; p<0.001, respectively), and in knee flexion range of motion (p<0.001).

SIGNIFICANCE

Based on our findings, barefoot walking should be used primarily during daily activities if the environment is conducive. Only one year of experience with minimalistic footwear seems insufficient and an intervention should be incorporated to change the gait pattern when transitioning to full minimalistic footwear walking.

Simulation of Lower Limb Muscle Activation Using Running Shoes with Different Heel-to-Toe Drops Using Opensim

BACKGROUND

Although numerous studies have been conducted to investigate the acute effects of shoe drops on running kinematics and kinetic variables, their effects on muscle forces remain unknown. Thus, the primary aim of this study was to compare the muscle force, kinematics, and kinetic variables of habitually rearfoot runners with heel-to-toe drops of negative 8 mm shoes (minimalist shoes) and positive 9 mm shoes (normal shoes) during the running stance phase by using musculoskeletal modeling and simulation techniques.

METHODS

Experimental data of lower limb kinematics, ground reaction force, and muscle activation from 16 healthy runners with rearfoot strike patterns were collected and analyzed in OpenSim. Using Matlab, the statistical parameter mapping paired t-test was used to compare the joint angle, moment, and muscle force waveform.

RESULTS

The results revealed differences in the sagittal ankle and hip angles and sagittal knee moments between the different heel-to-toe drops of running shoes. Specifically, it showed that the negative 8 mm running shoes led to significantly smaller values than the positive 9 mm running shoes in terms of the angle of ankle dorsiflexion, ankle eversion, knee flexion, hip flexion, and hip internal and hip external rotation. The peak ankle dorsiflexion moment, ankle plantarflexion moment, ankle eversion moment, knee flexion moment, knee abduction moment, and knee internal rotation also decreased obviously with the minimalist running shoes, while the lateral gastrocnemius, Achilleas tendon, and extensor hallucis longus muscles were obviously greater in the minimalist shoes compared to normal shoes. The vastus medialis, vastus lateralis and extensor digitorum longus muscles force were smaller in the minimalist shoes.

CONCLUSIONS

Runners may shift to a midfoot strike pattern when wearing negative running shoes. High muscle forces in the gastrocnemius lateral, Achilleas tendon, and flexor hallucis longus muscles may also indicate an increased risk of Achilleas tendonitis and ankle flexor injuries.

Daily activity in minimal footwear increases foot strength

The human foot is uniquely adapted to bipedal locomotion and has a deformable arch of variable stiffness. Intrinsic foot muscles regulate arch deformation, making them important for foot function. In this study we explore the hypothesis that normal daily activity in minimal footwear, which provides little or no support, increases foot muscle strength. Western adults wore minimal footwear for a six-month period (the “intervention” group). Foot strength, i.e., maximum isometric plantarflexion strength at the metatarsophalangeal joints, and foot biometrics were measured before and after the intervention. An additional group was investigated to add further insight on the long-term effects of footwear, consisting of Western adults with an average 2.5 years of experience in minimal footwear (the “experienced” group). This study shows that foot strength increases by, on average, 57.4% (p < 0.001) after six months of daily activity in minimal footwear. The experienced group had similar foot strength as the post intervention group, suggesting that six months of regular minimal footwear use is sufficient to gain full strength, which may aid healthy balance and gait.

Acute Effects of Barefoot and Minimalist Footwear on Medial Tibiofemoral Compartment Loading During Running: A Statistical Parametric Mapping Approach

The current investigation examined the effects of running barefoot and in minimalist footwear on medial tibiofemoral compartment loading, compared to conventional running trainers. Fifteen male runners ran over a force platform in five different footwear conditions (barefoot, Vibram five-fingers (Footwear A), Inov-8 (Footwear B) Nike-Free (Footwear C), and running trainer) whilst lower extremity kinematics were examined using a three-dimensional camera system. Medial compartment loading during the stance phase was explored using the knee adduction moment (KAM). In addition, the KAM instantaneous load rate was also calculated. Differences between footwear across the entire stance phase were examined using 1-dimensional statistical parametric mapping, whereas differences in discrete parameters were explored using one-way repeated measures ANOVA. Statistical parametric mapping revealed that Footwear B was associated with a significantly larger KAM compared to the running trainer from 15-20 and 25-30% of the stance phase and also Footwear C from 15-20% of the stance phase. The KAM instantaneous load rate was significantly larger in the barefoot (210.69 Nm/kg/s), Footwear A (200.23 Nm/kg/s) and Footwear B (186.03 Nm/kg/s) conditions in comparison to Footwear C (100.88 Nm/kg/s) and running trainers (92.70 Nm/kg/s). The findings from this study indicate that running barefoot and in minimalist footwear with the least midsole interface may place runners at increased risk of medial compartment knee OA, although further exploration using habitual barefoot / minimalist footwear users is required.

Differences in the kinetics and kinematics of supported and un-supported landings of the rugby union lineout

The aim of the current investigation was to comparatively examine the kinetics and kinematics of supported and un-supported landings during the rugby union lineout. Eleven male lineout jumpers were tested under two conditions, ‘supported’ in which the lifters maintained supportive contact with the jumper until the jumpers’ feet touched the floor and ‘un-supported’ in which the lifters released the jumper once they had caught the ball. Kinematics were examined using an eight camera motion capture system and kinetics using a force platform. Differences between conditions were examined using paired t-tests. The findings showed the instantaneous loading rate (supported = 212.9±102.5 body weight (BW)/s and un-supported = 449.0±142.4 BW/s) and vertical velocity (supported = 2.7±0.4 m/s and un-supported = 4.0±0.4 m/s) at foot contact were significantly larger in the un-supported condition. The findings from the current investigation indicate that if the lineout jumper is un-supported by the lifters in returning to the ground then their risk from injury is likely to be greater. Therefore, given the number of lineouts that are conducted per game it is recommended that this law be clarified to also specify supported lowering of the jumper at all levels of play.

Effects of Court Specific and Minimalist Footwear on the Biomechanics of a Maximal 180° Cutting Manoeuvre

Purpose. The aim of the current investigation was to examine the effects of different footwear on the kinetics and kinematics of performing a 180° cutting manoeuvre.

Methods. Nine male participants performed maximal 180° cut movements in court shoes, minimalist footwear, energy return, and conventional running shoes. Lower limb kinematic data were collected with the use of an 8 camera motion capture system, ground reaction forces were quantified with an embedded force platform, and tibial accelerations were obtained by means of an accelerometer. Differences in kinetics and kinematics between footwear were examined by one-way repeated measures ANOVA.

Results. The results showed that both instantaneous loading rate and peak tibial acceleration were significantly larger in the minimalist (282.91 BW/s and 6.38 g) and court (326.67 BW/s and 6.35 g) footwear compared with the conventional (143.19 BW/s and 5.46 g) and energy return (106.14 BW/s and 4.98 g) footwear. In addition, peak inversion was revealed to be significantly larger in the minimalist (16.36°) than in conventional (11.86°), court (12.61°), and energy return (10.12°) footwear.

Conclusions. These findings indicate that minimalist and court footwear may place athletes at increased risk from injury when performing 180° cut movements.

The Effects of Barefoot and Barefoot Inspired Footwear Running on Tibiofemoral Kinetics

The 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.

Fifteen 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.

The 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).

This indicates that running barefoot and in barefoot inspired footwear may place runners at increased risk from running-related tibiofemoral pathologies.

Effects of minimalist and maximalist footwear on Achilles tendon load in recreational runners

The current investigation aimed to comparatively examine the effects of minimalist, maximalist and conventional footwear on Achilles tendon forces (ATF) during running. Twelve male runners (age 23.11±5.01 years, height 1.78±0.10 cm and body mass 77.13±7.89 kg) ran at 4.0 m/s in the three footwear conditions. ATF’s were calculated using Opensim software allowing the magnitudal and temporal aspects of the ATF to be quantified. Differences between footwear were examined using one-way repeated measures ANOVA. The results showed the peak ATF was significantly larger in minimalist footwear (5.97±1.38 body weight (BW)) compared to maximalist (5.07±1.42 BW). In addition it was revealed that ATF per mile was significantly larger in minimalist (492.31±157.72 BW) in comparison to both maximalist (377.31±148.06 BW) and conventional (402.71±125.51 BW) footwear. Given the relationship between high ATF and Achilles tendon degradation, the current investigation indicated that minimalist footwear may increase runners risk for Achilles tendon injury.

Effects of conventional and minimalist footwear on patellofemoral and Achilles tendon kinetics during netball specific movements

Netball is a physically demanding sport that is associated with a high incidence of chronic injuries. Currently there is a trend towards the utilisation of minimalist footwear in netball players as opposed to more conventional netball trainers. The current investigation aimed to examine the effects of netball specific and minimalist footwear on patellofemoral and Achilles tendon loads during netball specific motions. Fifteen female netballers performed both run and cut movements when wearing conventional netball footwear and also a minimalist trainer. Kinematics of the lower extremities were quantified using a motion analysis system alongside ground reaction force information which was obtained using a force platform. Patellofemoral force (PTF), patellofemoral pressure (PP) and Achilles tendon forces (ATF) were quantified using predictive methods and examined between footwear using repeated measures ANOVA. The results indicate that patellofemoral loads (run – PTF: netball specific = 5.56 / minimalist = 4.74 body weight (BW); – PP: netball specific = 13.17 / minimalist = 11.89 MPa; cut – PTF: netball specific = 5.65 / minimalist = 4.82 BW; – PP; netball specific = 14.05 / minimalist = 12.88 MPa) were significantly larger in the conventional footwear compared to minimalist in both movements. Achilles tendon forces (run: netball specific = 4.43 / minimalist = 5.47; cut: netball specific = 4.32 / minimalist = 5.29 BW) were however significantly larger in the minimalist compared to the conventional footwear. Taking the proposed association between knee loading and patellofemoral pathology, the risk from knee injuries in netballers may be reduced via minimalist footwear. However, taking into account the equivalent increases in Achilles tendon forces, this may increase the likelihood of overuse Achilles tendon injuries.

The Influence of Minimalist Footwear on Knee and Ankle Load during Depth Jumping

Plyometric training is used by athletes to promote strength and explosive power. However plyometric activities such as depth jumping are associated with a high incidence of injuries. This study examined the influence of minimalist and conventional footwear on the loads experienced by the patellofemoral joint and Achilles tendon. Patellofemoral and Achilles tendon forces were obtained from ten male participants using an eight-camera 3D motion capture system and force platform data as they completed depth jumps in both footwear conditions. Differences between footwear were calculated using paired t-tests. The results show that the minimalist footwear were associated with significantly lower patellofemoral contact force/pressure and also knee abduction moment. It is therefore recommended, based on these observations, that those who are susceptible to knee pain should consider minimalist footwear when performing plyometric training.

The Effects of Barefoot and Shod Running on Limb and Joint Stiffness Characteristics in Recreational Runners

The authors aimed to determine the effects of barefoot (BF) and several commercially available barefoot-inspired (BFIS) footwear models on limb and joint stiffness characteristics compared with conventional footwear (CF). Fifteen male participants ran over a force platform at 4.0 m.s(-1), in BF, BFIS, and CF conditions. Measures of limb and joint stiffness were calculated for each footwear. The results indicate that limb and knee stiffness were greater in BF and minimalist BFIS than in CF. CF and more structured BFIS were associated with a greater ankle stiffness compared with BF and minimalist BFIS. These findings serve to provide further insight into the susceptibility of runners to different injury mechanisms as a function of footwear.

Effects of barefoot and barefoot inspired footwear on knee and ankle loading during running

BACKGROUND

Recreational runners frequently suffer from chronic pathologies. The knee and ankle have been highlighted as common injury sites. Barefoot and barefoot inspired footwear have been cited as treatment modalities for running injuries as opposed to more conventional running shoes. This investigation examined knee and ankle loading in barefoot and barefoot inspired footwear in relation to conventional running shoes.

METHOD

Thirty recreational male runners underwent 3D running analysis at 4.0m·s(-1). Joint moments, patellofemoral contact force and pressure and Achilles tendon forces were compared between footwear.

FINDINGS

At the knee the results show that barefoot and barefoot inspired footwear were associated with significant reductions in patellofemoral kinetic parameters. The ankle kinetics indicate that barefoot and barefoot inspired footwear were associated with significant increases in Achilles tendon force compared to conventional shoes.

INTERPRETATION

Barefoot and barefoot inspired footwear may serve to reduce the incidence of knee injuries in runners although corresponding increases in Achilles tendon loading may induce an injury risk at this tendon.