Lateral Forefoot Research Articles

Midfoot Function Before and After Total Ankle Arthroplasty.

Information regarding the effect of total ankle arthroplasty (TAA) on midfoot function is extremely limited. The purpose of this study was to characterize midfoot region motion and power during walking in people before and after TAA. This was a prospective cohort study of 19 patients with end-stage ankle arthritis who received a TAA and 19 healthy control group participants. A motion capture and force plate system was used to record sagittal and transverse plane first metatarsal and lateral forefoot with respect to hindfoot motion, as well as sagittal plane midfoot region positive and negative peak power during walking. Parametric or nonparametric tests to examine differences and equivalence across time were conducted. Comparisons to examine differences between postoperative TAA group and control group foot function were also performed. Involved-limb midfoot function was not different between the preoperative and 6-month postoperative time point in the TAA group (all P ≥ .17). Equivalence testing revealed similarity in all midfoot function variables across time (all P < .05). Decreased first metatarsal and lateral forefoot motion, as well as positive peak power generation, were noted in the TAA group postoperative involved limb in comparison to the control group (all P ≤ .01). The similarity of midfoot function across time, along with differences in midfoot function in comparison to controls, suggests that TAA does not change midfoot deficits by 6 months postoperation. Level II, prospective cohort study.

Biomechanical Response to External Biofeedback During Functional Tasks in Individuals With Chronic Ankle Instability.

Altered biomechanics displayed by individuals with chronic ankle instability (CAI) is a possible cause of recurring injuries and posttraumatic osteoarthritis. Current interventions are unable to modify aberrant biomechanics, leading to research efforts to determine if real-time external biofeedback can result in changes. To determine the real-time effects of visual and auditory biofeedback on functional-task biomechanics in individuals with CAI. Crossover study. Laboratory. Nineteen physically active adults with CAI (7 men, 12 women; age = 23.95 ± 5.52 years, height = 168.87 ± 6.94 cm, mass = 74.74 ± 15.41 kg). Participants randomly performed single-limb static balance, step downs, lateral hops, and forward lunges during a baseline and 2 biofeedback conditions. Visual biofeedback was given through a crossline laser secured to the dorsum of the foot. Auditory biofeedback was given through a pressure sensor placed under the lateral foot and connected to a buzzer that elicited a noise when pressure exceeded the set threshold. Cues provided during the biofeedback conditions were used to promote proper biomechanics during each task. We measured the location of center-of-pressure (COP) data points during balance with eyes open and eyes closed for each condition. Plantar pressure in the lateral column of the foot during functional tasks was extracted. Secondary outcomes of interest were COP area and velocity, time to boundary during static balance, and additional plantar-pressure measures. Both biofeedback conditions reduced COP in the anterolateral quadrant while increasing COP in the posteromedial quadrant of the foot during eyes-open balance. Visual biofeedback increased lateral heel pressure and the lateral heel and midfoot pressure-time integral during hops. The auditory condition produced similar changes during the eyes-closed trials. Auditory biofeedback increased heel pressure during step downs and decreased the lateral forefoot pressure-time integral during lunges. Real-time improvements in balance strategies were observed during both external biofeedback conditions. Visual and auditory biofeedback appeared to effectively moderate different functional-task biomechanics.

Comparison between the plantar pressure effects of toe separators and insoles in patients with hallux valgus at a one-month follow-up

BackgroundVarious designs of foot orthoses for hallux valgus have been developed to reduce foot pain. The plantar pressure assessment can determine the better intervention. This study aimed to compare the effectiveness of plantar pressure distribution in patients with hallux valgus during walking with toe separator and insole. MethodPatients with hallux valgus were randomized into one of two interventions: prefabricated toe separator or customized insole. The plantar pressure distribution of the participants was measured during walking with the devices after use for one month with an in-shoe measurement system. ResultsTwenty-three participants were analyzed. After 1-month, significant peak pressures and pressure-time integral reductions were observed during walking in the middle forefoot (64.28 kPa and 28.97 kPa s, respectively) and lateral forefoot regions (54.03 kPa and 22.30 kPa s, respectively) after insole use compared with a toe separator. ConclusionsAfter one month of use, the customized insole was more effective in plantar pressure reduction than the toe separator for a hallux deformity.

Foot joint coupling variability differences between habitual rearfoot and forefoot runners prior to and following an exhaustive run

As joint coupling variability has been associated with running-related lower extremity injury, the purpose of this study was to identify how variability within the foot may be different between forefoot (FFS) and rearfoot strike (RFS) runners. Identifying typical variability in uninjured runners may contribute to understanding of ideal coordination associated with running foot strike patterns.Fifteen FFS and 15 RFS runners performed a maximal-effort 5 km treadmill run. A 7-segment foot model identified 6 functional articulations (rearfoot, medial and lateral midfoot and forefoot, and 1st metatarsophalangeal) for analysis. Beginning and end of the run motion capture data were analyzed. Vector coding was used to calculate 6 joint couples. Standard deviations of the coupling angles were used to identify variability within subphases of stance (loading, mid-stance, terminal, and pre-swing). Mixed between-within subjects ANOVAs compared differences between the foot strikes, pre and post run.Increased variability was identified within medial foot coupling for FFS and within lateral foot coupling for RFS during loading and mid-stance. The exhaustive run increased variability during mid-stance for both groups.Interpretation. Joint coupling variability profiles for FFS and RFS runners suggest different foot regions have varying coordination needs which should be considered when comparing the strike patterns.

Lomber Spinal Stenozlu Hastalarda Yürüme Enerji Tüketimi ve Plantar Basınç Dağılımının Değerlendirilmesi: Kesitsel vaka kontrol çalışması

Objective: To evaluate the alterations of walking energy expenditure and plantar pressure distribution of patients with lumbar spinal stenosis. Material and Methods: Twenty-six subjects of both genders were included in the study, 13 patients suffering from lumbar spinal stenosis served as patient group and 13 healthy participants served as a control group. Preferred walking speeds were determined on the over ground. Oxygen consumption was recorded via a metabolic analyzer during walking on a treadmill for 2 km at preferred walking speed that determined on the over ground. Net oxygen consumption and oxygen cost were calculated for obtaining walking energy consumption. Plantar area was subdivided into six zones to measure plantar pressure distribution with a pedobarography device. Results: Compared with control group, patient group had significantly lower preferred walking speed (62.56±13.90 m/minimum and 76.66±10.90 m/minimum, p=0.008) and maximum walking distance [674.6 (105.0- 2000.0) m and 2000.0 (2000.0-2000.0) m, p=0.019]. However, there were no statistically significant differences between groups in terms of energy expenditure parameters during walking at preferred walking speed (p>0.05). Similar findings were recorded between right and left foot with regard to weight distribution (%) to forefoot/hindfoot in patient group in the static pedobarographic measurements (p>0.05). Contact area value was significantly different between the affected and unaffected side at lateral forefoot in patient group (22.73±2.97 and 24.90±2.9, p=0.001). Conclusion: Patients with lumbar spinal stenosis do not exhibit more pressure on unaffected side compared to healthy subjects in both static and dynamic condition except contact area of lateral forefoot. Patient group optimized energy expenditure and oxygen cost by reducing their preferred walking speed owing to the pain.

An exploration of changes in plantar pressure distributions during walking with standalone and supported lateral wedge insole designs

BackgroundLateral wedge insoles (LWI), standalone or with medial arch support (supported-LWI), have been thoroughly investigated for their effects on modifying gait biomechanics for people with knee osteoarthritis. However, plantar pressure distribution between these insole types has not been investigated and could provide insight towards insole prescription with concomitant foot symptoms taken into consideration.MethodsIn a sample of healthy individuals (n = 40), in-shoe plantar pressure was measured during walking with LWI, with or without medial arch support (variable- and uniform-stiffness designs), and a flat control insole condition. Pressure data from the plantar surface of the foot were divided into seven regions: medial/lateral rearfoot, midfoot, medial/central/lateral forefoot, hallux. Plantar pressure outcomes assessed were the medial-lateral pressure index (MLPI) for the whole foot, and the peak pressure, pressure-time integral (PTI), and contact area in each plantar region. Comfort in each insole condition was rated as a change relative to the flat control insole condition. Repeated-measures analyses of variance were calculated to compare the plantar pressure outcomes between insole conditions.ResultsRegionally, medial rearfoot and forefoot pressure were reduced by all wedged insoles, with the variable-stiffness supported-wedge showing greater reductions than the standalone wedge. Lateral rearfoot and forefoot pressure were reduced by both supported-LWI, but unchanged by the standalone wedge. In the midfoot, the standalone wedge maintained pressure but reduced regional contact area, while both supported-LWI increased midfoot pressure and contact area. All LWI increased the MLPI, indicating a lateral shift in plantar pressure distribution throughout the weightbearing phase of gait. Comfort ratings were not significantly different between insole conditions.ConclusionsRegional differences in plantar pressure may help determine an appropriate lateral wedge insole variation to avoid exacerbation of concomitant foot symptoms by minimizing pressure in symptomatic regions. Lateral shifts in plantar pressure distribution were observed in all laterally wedged conditions, including one supported-LWI that was previously shown to be biomechanically ineffective for modifying knee joint load distribution. Thus, shifts in foot centre of pressure may not be a primary mechanism by which LWI can modify knee joint load distribution for people with knee osteoarthritis.

Functional characterization of plantar pressure patterns in gait of typically developing children using dynamic pedobarography

BackgroundAbnormal foot posture is a common complaint presented in pediatric and pediatric orthopedic clinics. Functional, objective assessment of foot posture, with the potential for early identification of pathologic foot deformities, has, however, been lacking to date. While quantifying functional and regional impulses via dynamic pedobarography can improve the clinical assessment of children’s feet, normative values have not yet been reported or characterized. Research QuestionThe objectives of this study were to: (1) quantify and characterize the pattern and spectrum of foot impulses in walking-aged, typically developing children; and (2) compare these to impulses from non-disabled adults. MethodsFoot impulses of 102 participants (52 female) in five pre-determined age groups (2−3, 4–6, 7–10, 11−14, 15−17 years) were examined using dynamic pedobarography. Each pressure map (3 per foot per child) was divided according to anatomical foot regions: the hallux, heel, medial forefoot, lateral forefoot, lesser toes (D2 to D5), and midfoot. The impulse was calculated for each region and used to generate regional percent impulses and impulse ratios to assess anteroposterior and mediolateral balance within the foot. ResultsThe impulse through the midfoot was highest in the youngest age group, with a corresponding lower impulse through the medial forefoot. As age advanced, the midfoot impulse decreased (p = 0.001), and the forefoot balance shifted slightly more medially (%Medial Forefoot: p = 0.004; Medial-Lateral Forefoot Balance: p = 0.019). When compared to adults, there were no significant differences between 15−17 year old children and adults in any of the regional percent impulses and impulse ratios. This indicates that skeletal maturity of the foot by late adolescence results in functional characteristics seen in adults. SignificanceThe age-standardized norms of functional and regional impulse measures in children reported in this study can be used as a comparative benchmark in the clinical assessment of children presenting with various foot deformities.

ASSESSING THE POTENTIAL INFLUENCE OF DIFFERENT WALKING STRATEGIES ON PLANTAR PRESSURE DISTRIBUTION TRIGGERED BY A PORTABLE BIOFEEDBACK-BASED GAIT TRAINING DEVICE

Plantar pressure refers to the interfacial contact pressure between the foot and the supporting surface during daily locomotor activities. Information derived from plantar pressure measures is essential in gait and posture research for diagnosing patho-mechanics associated with the musculoskeletal diseases. In particular, it is compulsory to reduce the abnormally high plantar pressure in people with diabetes for the prevention and treatment of foot ulcerations in this population. In this study, a portable biofeedback-based gait training device is developed to advocate able-bodied subjects to adopt different movement patterns in walking to manipulate the plantar pressure distribution under the foot. Through the simultaneous detection of the plantar pressure pattern and the kinematics of the lower extremity joints, it was revealed that the unloading effects for the plantar site in particular to the lateral forefoot subareas were more abundant through biofeedback-assisted gait alterations than the self-awareness control for gait adjustment. In addition, the corresponding relationship between joint coordination and pressure redistribution pattern was obtained, which could potentially be used in gait retraining interventions to correct abnormal plantar pressure patterns in people with diabetes.

Biomechanical Response to External Biofeedback During Functional Tasks in Individuals With Chronic Ankle Instability

Altered biomechanics displayed by individuals with chronic ankle instability (CAI) is a possible cause of recurring injuries and posttraumatic osteoarthritis. Current interventions are unable to modify aberrant biomechanics, leading to research efforts to determine if real-time external biofeedback can result in changes. To determine the real-time effects of visual and auditory biofeedback on functional-task biomechanics in individuals with CAI. Crossover study. Laboratory. Nineteen physically active adults with CAI (7 men, 12 women; age = 23.95 ± 5.52 years, height = 168.87 ± 6.94 cm, mass = 74.74 ± 15.41 kg). Participants randomly performed single-limb static balance, step downs, lateral hops, and forward lunges during a baseline and 2 biofeedback conditions. Visual biofeedback was given through a crossline laser secured to the dorsum of the foot. Auditory biofeedback was given through a pressure sensor placed under the lateral foot and connected to a buzzer that elicited a noise when pressure exceeded the set threshold. Cues provided during the biofeedback conditions were used to promote proper biomechanics during each task. We measured the location of center-of-pressure (COP) data points during balance with eyes open and eyes closed for each condition. Plantar pressure in the lateral column of the foot during functional tasks was extracted. Secondary outcomes of interest were COP area and velocity, time to boundary during static balance, and additional plantar-pressure measures. Both biofeedback conditions reduced COP in the anterolateral quadrant while increasing COP in the posteromedial quadrant of the foot during eyes-open balance. Visual biofeedback increased lateral heel pressure and the lateral heel and midfoot pressure-time integral during hops. The auditory condition produced similar changes during the eyes-closed trials. Auditory biofeedback increased heel pressure during step downs and decreased the lateral forefoot pressure-time integral during lunges. Real-time improvements in balance strategies were observed during both external biofeedback conditions. Visual and auditory biofeedback appeared to effectively moderate different functional-task biomechanics.

The Difference of In-Shoe Plantar Pressure between Level Walking and Stair Walking

Category:Basic Sciences/Biologics; OtherIntroduction/Purpose:Stair walking is one of common activities of daily living. It is more demanding than level walking and can aggravate discomfort of the foot, such as Morton’s neuroma, plantar fasciitis, Achilles tendinitis, pressure related-ulcer, and etc. Therefore, analysis of increased pressure in specific plantar area at stair walking can be used as a risk assessment of foot discomfort and basic data in the clinical field. The purpose of this study is to analyze plantar pressure distribution and pressure patterns during gait cycle at stair walking compared to level walking.Methods:Fourty healthy male adults were recruited. Radiologic measurements and gait analysis were performed to check participants’ normality, and 35 healthy males with 20-28 years old were included. They performed level walking (18 meters walkway), stair (26 steps stair, height:16.7cm, depth:29.8cm) ascending, and descending in same type of running shoes.Measurements of in-shoe plantar pressure including peak pressure, pressure-time integral (PTI) were done by Pedar-X system. The sole was masked in 7 segments (hallux, 2nd-5th toes, medial forefoot, central forefoot, lateral forefoot, midfoot, heel region) to analyze properly. Percentages were assigned in relation to the size for each mask segment. Statistical analysis was performed using repeated measure ANOVA, and Bonferroni post hoc test was done.Results:PP in all regions except for the midfoot were higher during level walking than stair walking. During stair descent, PP in all the regions except for the midfoot were generally lower than other types of walking, but it was the highest in the midfoot region. PTI in the medial and central forefoot was higher during stair descent than level walking. PTI in the central and lateral forefoot, and the midfoot was higher when stair ascending than level walking. PTI in the heel region was the highest during level walking, followed by stair ascent, stair descent.Conclusion:The risk of aggravation of discomfort in the midfoot area increases when stair descending. The medial region of forefoot bear high pressure load during stair descent, and the lateral region of forefoot and the midfoot region bear high pressure load during stair ascent. This is the first study to show plantar pressure patterns during level and stair walking in the large healthy gender-controlled population. We recommend that patients with pressure related foot lesions in the forefoot or midfoot avoid stair walking.

Foot Loading Symmetry is Improved after Unicompartmental Knee Arthroplasty

Category:Basic Sciences/Biologics; Midfoot/ForefootIntroduction/Purpose:Unicompartmental Knee Arthroplasty (UKA) is a surgical option for osteoarthritis in a single compartment of the knee. Compared to Total Knee Arthroplasty (TKA), UKA is less expensive, retains the cruciate ligaments and results in lower post-operative morbidity.[1] It has been reported that about 10 percent of UKAs require revision to TKA for multiple reasons. In TKA, ankle alignment has demonstrated a significant effect on outcomes and function. [2] Plantar pressure, a measure of foot and ankle loading, changes after TKAs but has yet to be evaluated in UKAs. The purpose of this study is to evaluate the effects of medial UKA on plantar pressure which may be a variable that contributes to revisions in these patients.Methods:Following IRB approval and informed consent, we evaluated 7 adults (14 Feet) (average age 62; range: 54 to 68 years old; 4F/ 3M). All participants walked at a self-selected speed pre surgery and 7 months post-surgery. The Pedar insole pressure system (Novel), with 99 sensors per insole, was used to collect bilateral plantar pressure during gait at 100 Hz. All participants wore the same type of shoes (Nike Zoom) for the test. The insole was divided into 9 regions for analysis2 (Figure 1). The maximum pressure (MP) within each foot region was calculated for each step and averaged over all steps. Paired and unpaired t- tests were performed to identify differences in the MP from pre to post-op and between operated and contralateral sides, respectively.Results:An average of 24 steps were recorded from each patient pre and post operatively. MP became more symmetrical between feet post-operatively, with significant improvements in bilateral symmetry observed in the medial heel, medial and lateral forefoot regions (all p<0.01). The MP in the lateral midfoot region of the operative side increased during ambulation post- operatively (p<0.05). The MP in the lateral forefoot region of the non-operative side decreased post-operatively (p<0.01).Conclusion:Our results indicate that foot loading, as assessed through plantar pressure, becomes more symmetrical after unilateral UKA and may also affect non-operative foot loading. Although our sample size is small, our data is comparable with a similar study done in TKA patients which reported changes forefoot and lateral midfoot loading.

Children with Obesity Experience Different Age-Related Changes in Plantar Pressure Distributions: A Follow-Up Study in China.

Age is a key factor in plantar pressure distributions during the development of obese children. However, the existing evidence for age-related plantar pressures of obese children is not sufficient to make clear how the plantar pressures would change with the increasing age. This study aimed to evaluate the plantar pressure redistributions of obese children after a three-year follow-up and to further compare these changes with normal-weighted children. Ten obese children and eleven normal-weighted counterparts were involved in this study. Plantar pressure measurements were undertaken using a Footscan® plantar pressure plate on two test sessions three years apart. Peak pressure, pressure-time integral, standard maximum force, and z-scores of these variables were analyzed. Loading transference analyses were applied to detect the different loading transferring mechanisms between obese and normal-weighted children. Significantly increased plantar pressures were observed at the lateral forefoot and midfoot for obese children, which gradually deviated from those of normal-weighted children over the 3 years. With the increasing age, obese children displayed a lateral loading shift at the forefoot in contrast to the normal-weighted. Early interventions are cautiously recommended for obese children before the plantar loading deviation gets worse as they grow older.

The Impact of Overweight and Obesity on Plantar Pressure in Children and Adolescents: A Systematic Review.

We aimed to synthesise the results of previous studies addressing the impact of overweight and obesity on plantar pressure in children and adolescents. An electronic search of scientific literature was conducted using PubMed, Cochrane and Scopus database, with keywords: “plantar pressure” AND “children” AND “obesity”; “plantar pressure” AND “adolescents” AND “obesity”, “plantar pressure” AND “children” AND “overweight”, “plantar pressure” AND “adolescents” AND “overweight”. Twenty-two articles were included in the review and the following data were recorded: authors, publication year, type of technology (systems, software) for the determination of plantar pressure, study characteristics. Most of the articles used dynamic plantar pressure determination with only four using static plantar pressure measurement. Using ultrasonography with static plantar pressure determination, the correlation between structural and functional changes in the feet of obese children. In overweight and obese children and adolescents, important findings were recorded: higher contact area, increased maximum force beneath the lateral and medial forefoot, increased pressure–time integral beneath the midfoot and 2nd–5th metatarsal regions. Significantly increased foot axis angle and significantly flatter feet were observed in obese subjects in comparison to their normal-weight counterparts. The obese children presented increased midfoot fat pad thickness, with decreased sensitivity of the whole foot and midfoot.

The biomechanical effects of pronated foot function on gait. An experimental study.

The relationship between foot kinematics and the development of lower extremity musculoskeletal disorders (MSD) has been the focus of recent attention. However, most studies evaluated static foot type and not dynamic foot function. The purpose was to compare lower limb and foot kinematics, and plantar pressures during gait in physically active individuals with pronated and non-pronated foot function. Foot function in 154 adult participants was documented as pronated (n=63) or neutral (n=91) using 2 established methods: The Foot Posture Index and the Center of Pressure Excursion Index. Difference between the groups in triplanar motion of the lower limb during barefoot gait was evaluated using a 3D motion capture system incorporating the Oxford Foot Model. Dynamic parameters of plantar pressure were recorded using a pressure platform. Anterior-posterior pelvic tilt range of motion (ROM), peak knee internal rotation, forefoot dorsiflexion ROM, peak forefoot abduction, and rearfoot eversion were all increased in those with pronated foot function. Hallux contact time and time to peak force under the medial forefoot were increased with pronated foot function, and maximal force under the lateral forefoot was reduced. Pronated foot function affected the whole lower limb kinematic chain during gait. These kinematic alterations could increase the risk of developing MSD. Further studies should elucidate the relationship between pronated foot function and MSD, and, if confirmed, foot function should be evaluated in clinical practice for patients with lower limb and low back pain.

Using a Crossline Laser to Predict Peak Plantar Pressure During Walking.

Developing low-cost assessment tools to quantify ankle biomechanics in a clinical setting may improve rehabilitation for patients with chronic ankle instability (CAI). To determine whether a crossline laser can predict peak plantar pressure during walking. Descriptive laboratory study. Laboratory. Twenty-five participants with CAI (9 men, 16 women; age = 20.8 ± 2.3 years, height = 170.4 ± 10.4 cm, mass = 78.9 ± 22.4 kg). Participants completed 30 seconds of treadmill walking with a crossline laser fixed to their shoe while, simultaneously, a video camera recorded the laser projection on the wall and an in-shoe plantar-pressure system measured plantar pressure. Peak laser rotation and peak plantar pressure of the lateral midfoot and forefoot. With respect to peak plantar pressure, peak rotation of the laser during walking explained 57% of the variance in the lateral midfoot and 64% in the lateral forefoot. The crossline laser may be a valuable clinical tool for predicting lateral peak plantar pressure in patients with CAI during walking.

Analysis of Differences in the Degree of Biomechanical Adaptation according to Habituation to Different Heel Heights.

This study aims to comprehensively investigate whether there are any differences in the degree of biomechanical adaptation according to habituation to different heel heights. The biomechanical characteristics of 54 subjects in 3 groups habituated to three heel heights (low, medium-high, and high heels) were evaluated by the measurement of surface EMG, myotonometer (e.g., measurement of muscle tension), foot pressure, and lumbosacral angle, and comparative analysis was carried out to find out whether they showed differences in the comfort visual analog scale (comfort VAS). Wearers of high-heeled shoes (6 cm or more in heel height), in foot pressure comparison, showed significantly high peak pressure in the mask of the hallux, high maximum peak EMG in the gastrocnemius medius (GM), and a high percentage of maximum voluntary isometric contraction (%MVIC) in the plantar flexor. Wearers of low-heeled shoes (3 cm and below in heel height) showed the highest plantar peak pressure in the lateral forefoot and midfoot, the highest contact area in midfoot, the highest %MVIC in the plantar flexion and dorsiflexion of the tibialis anterior (TA), and the highest stiffness in the TA, and they showed the lowest static balance ability with eyes open (EO) among the three groups. It was found that there were significant differences between those habituated to high-heeled shoes and those not habituated to high-heeled shoes and that longtime wearing of high-heeled shoes brings about biomechanical adaptive changes in the human body.

Mechanical character of lower limb for table tennis cross step maneuver

The agile footwork is a basic but important skill, how to efficiently grasp and improve its performance has always interested coaches and athletes, beginners particularly. The purpose of this study was to investigate the differences in kinetics and kinematics of the cross step between professional athletes and novice athletes using the Oxford foot model. Twenty-two male participants (professional athletes, 11; novice athletes, 11) with dominant right feet participated in the table tennis cross step test. A Vicon motion analysis system and a Novel Pedar insole plantar pressure measurement system were used to record kinematic and kinetic data, respectively. Professional athletes showed significantly smaller forefoot plantarflexion and abduction, but larger hallux dorsiflexion at the cross step ending. In addition, they also showed significantly larger forefoot dorsiflexion and adduction but smaller forefoot eversion as well as rearfoot inversion than novice athletes at the forward-end of the step. In the entire motion, professional athletes performed significantly smaller joints range of motion, especially the hindfoot with respect to tibia angles. Concerning plantar relative load, professional athletes were significantly greater than that of novice athletes in the other toes, lateral forefoot and rear foot. Professional athletes possessed higher footwork agility and greater foot motor technique. The findings on the internal mechanisms of the cross step could help coaches and novice athletes understand the mechanical efficiencies in stroke finishing leading to improvements in performance.

Effect of additional body weight on arch index and dynamic plantar pressure distribution during walking and gait termination.

The medial longitudinal arch is considered as an essential feature which distinguishes humans from other primates. The longitudinal arch plays a supporting and buffering role in human daily physical activities. However, bad movement patterns could lead to deformation of arch morphology, resulting in foot injuries. The authors aimed to investigate any alterations in static and dynamic arch index following different weight bearings. A further aim was to analyze any changes in plantar pressure distribution characteristics on gait during walking and stopping, Twelve males were required to complete foot morphology scans and three types of gait tests with 0%, 10%, 20% and 30% of additional body weight. The dynamic gait tests included walking, planned and unplanned gait termination. Foot morphology details and plantar pressure data were collected from subjects using the Easy-Foot-Scan and Footscan pressure platform. No significant differences were observed in static arch index when adding low levels of additional body weight (10%). There were no significant changes observed in dynamic arch index when loads were added in the range of 20% to 30%, except in unplanned gait termination. Significant maximal pressure increases were observed in the rearfoot during walking and in both the forefoot and rearfoot during planned gait termination. In addition, significant maximum pressure increases were shown in the lateral forefoot and midfoot during unplanned gait termination when weight was increased. Findings from the study indicated that excessive weight bearing could lead to a collapse of the arch structure and, therefore, increases in plantar loading. This may result in foot injuries, especially during unplanned gait termination.

ANALYSIS OF A DIFFERENCE IN THE BIOMECHANICAL CHARACTERISTICS ACCORDING TO THE HABITUATION BY HEIGHTS OF SHOES: HIGH-HEEL AND LOW-HEEL SHOES

This study was performed to comprehensively investigate whether there is a difference in the biomechanical characteristics according to the habituation by heights of shoes of those who habituate to high heeled shoes and low heeled shoes. The women with low heeled habituation show significantly higher values of peak pressures in the lateral forefoot and midfoot areas, and wider contact areas in toes and midfoot than the women with high heeled habituation for the contact area. From the EMG comparison, the women with high heeled habituation show significantly higher maximum peak EMG in GM, and from the percentage of maximum voluntary isometric contraction (%MVIC), the women with high heeled habituation show significantly higher values of the plantarflexion in GM the low heeled shoe user. For the static balance, the women with high heeled habituation show significantly greater values with eyes open. The study was able to verify that there is a significant difference in biomechanical fitness such as foot pressure, %MVIC, etc. Based on the result, this study can be utilized as base data to develop a customized insole that disperses pressure and softens shock absorption of the high heeled shoes.

Plantar Loads of Habitual Forefoot Strikers during Running on Different Overground Surfaces

The objective of this study is to investigate plantar loads characteristics of habitual forefoot strike runners while running on different surfaces. Twenty-six runners (age: 28.2 ± 6.8 y, height: 172.9 ± 4.1 cm, weight: 67.7 ± 9.6 kg, BMI (body mass index): 22.6 ± 2.8 kg/m2, running age: 5.0 ± 4.2 y, running distance per week: 14.6 ± 11.7 km) with habitual forefoot strike participated in the study. Runners were instructed to run at 3.3 ± 0.2 m/s on three surfaces: grass, synthetic rubber and concrete. An in-shoe pressure measurement system was used to collect and analyze plantar loads data. Running on the synthetic rubber surface produced a lower plantar pressure in the lateral forefoot (256.73 kPa vs. 281.35 kPa, p = 0.006) than running on concrete. Compared with the concrete surface, lower pressure–time integrals were shown at the central forefoot (46.71 kPa⋅s vs. 50.73 kPa⋅s, p = 0.001) and lateral forefoot (36.13 kPa⋅s vs. 39.36 kPa⋅s, p = 0.004) when running on the synthetic rubber surface. The different surfaces influence plantar loads of habitual forefoot strikers and runners should choose appropriate overground surface to reduce the risk of lower extremity musculoskeletal injuries.