Does QUICK TAPE Offer Comparable Support and Off-loading as Low-Dye Taping?

BACKGROUND: Low-Dye taping is commonly used to manage foot pathologies and pain. Precut one-piece QUICK TAPE was designed to facilitate taping. However, no study to date has demonstrated that QUICK TAPE offers similar support and off-loading as traditional taping. METHODS: This pilot study compared the performance of QUICK TAPE and low-Dye taping in 20 healthy participants (40 feet) with moderate-to-severe pes planus. Study participants completed arch height index (AHI), dynamic plantar assessment with a plantar pressure measurement system, and subjective rating in three conditions: barefoot, low-Dye, and QUICK TAPE. The order of test conditions was randomized for each participant, and the taping was applied to both feet based on a standard method. A generalized estimating equation with an identity link function was used to examine differences across test conditions while accounting for potential dependence in bilateral data. RESULTS: Participants stood with a significantly greater AHI (P = .007) when either taping was applied compared with barefoot. Participants also demonstrated significantly different plantar loading when walking with both tapings versus barefoot. Both tapings yielded reduced force-time integral (FTI) in the medial and lateral forefoot and increased FTI under toes. Unlike previous studies, however, no lateralization of plantar pressure was observed with either taping. Participants ranked both tapings more supportive than barefoot. Most participants (77.8%) ranked low-Dye least comfortable, and 55.6% preferred QUICK TAPE over low-Dye. CONCLUSIONS: Additional studies are needed to examine the clinical utility of QUICK TAPE in individuals with foot pathologies such as heel pain syndrome and metatarsalgia.

Comparative Reliability of a Novel Electromechanical Device and Handheld Ruler for Measuring First Ray Mobility.

BACKGROUND: Quantifying first ray mobility is crucial to understand aberrant foot biomechanics. A novel device (MAP1st) that can perform measurements of first ray mobility in different weightbearing conditions, foot alignments, and normalization was tested. The reliability of these measurement techniques was assessed in comparison to a handheld ruler considered representative of the common clinical examination. METHODS: The study included 25 participants (50 feet). Two independent raters performed baseline, test-retest, and remove-replace measurements of first ray mobility with MAP1st and the handheld device. The effects of non-, partial, and full weightbearing in subtalar joint neutral and the resting calcaneal stance position were assessed. Measurement normalization relative to foot size was also investigated. Intra- and interclass correlation coefficients (ICCs) were calculated for each device between the 2 raters. In addition, Bland-Altman plots were constructed to determine if fixed biases or substantial outliers were present. RESULTS: Similar intrarater ICC values were found for both devices (≥0.85). However, interrater ICC values were substantially improved by MAP1st compared with the handheld device (0.58 vs 0.06). Bland-Altman plots demonstrated biases of 1.27 mm for the handheld ruler, and 2.88 to 0.05 mm and -1.16 to 0.00 for linear and normalized MAP1st measurements, respectively. Improved reliability was achieved with MAP1st for normalized assessments of first ray mobility while the foot was placed in partial- and full-weightbearing resting calcaneal stance positions. CONCLUSION: MAP1st provided reliable assessments of partial- and full-weightbearing first ray mobility. It should help investigators to explore the potential relationships between first ray function and aberrant foot biomechanics in future research. LEVEL OF EVIDENCE: Level II, prospective cohort study.

Association Between Running Shoe Characteristics and Lower Extremity Injuries in United States Military Academy Cadets.

BACKGROUND: Running-related overuse injuries are very common among recreational runners, with the reported annual injury rates ranging from 39% to 85%. Relatively few large prospective cohort studies have been conducted to investigate injury risk associated with different running shoe characteristics, and the results of the existing studies are often contradictory. PURPOSE/HYPOTHESIS: The purpose was to investigate the relationship between running shoe characteristics and lower extremity musculoskeletal injury. It was hypothesized that the risk of injury would be increased in individuals wearing shoes with minimal torsional stiffness and heel height compared with those wearing shoes with greater levels of torsional stiffness and heel height. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: The study included 1025 incoming cadets. Shoe torsional stiffness and heel height were calculated and recorded. Demographic data were recorded and analyzed as potential covariates. Lower extremity injuries sustained over 9 weeks during cadet basic training were documented by use of the Armed Forces Health Longitudinal Technology Application and the Cadet Illness and Injury Tracking System. Kaplan-Meier survival curves were estimated, with time to incident lower extremity injury as the primary outcome by level of the independent predictor variables. Risk factors or potential covariates were carried forward into multivariable Cox proportional hazards regression models. Absolute and relative risk reduction and numbers needed to treat were calculated. RESULTS: Approximately 18.1% of participants incurred a lower extremity injury. Cadets wearing shoes with moderate lateral torsional stiffness were 49% less likely to incur any type of lower extremity injury and 52% less likely to incur an overuse lower extremity injury than cadets wearing shoes with minimal lateral torsional stiffness, both of which were statistically significant observations. Injury risk was similar among cadets wearing shoes with minimal and extreme lateral torsional stiffness. CONCLUSION: Shoes with mild to moderate lateral torsional stiffness may be appropriate in reducing risk of lower extremity injury in cadets. Shoes with minimal lateral torsional stiffness should be discouraged in this population.

Hip muscle response to a fatiguing run in females with iliotibial band syndrome.

Impaired hip muscle function has often been cited as a contributing factor to the development of iliotibial band syndrome (ITBS), yet our full understanding of this relationship is not well established. The objective of this study was to examine the effect of fatigue on hip abductor muscle function in females with ITBS. Female runners, 20 healthy and 12 with a current diagnosis of ITBS, performed a treadmill run to fatigue. Prior-to and following the run to fatigue, gluteus medius strength and median frequency values (an indicator of fatigue resistance) were measured. Additionally, onset activation timing of the gluteus medius and tensor fascia latae was measured during overground running. Both healthy and injured runners demonstrated decreased gluteus medius strength following the run to fatigue (p = 0.01), but there was no interaction between groups (p = 0.78). EMG onset activation timing did not differ between groups for the gluteus medius (P = 0.19) and tensor fascia latae muscles (P = 0.52). Injured runners demonstrated decreased gluteus medius initial median frequency values suggestive of fatigue (P = 0.01). These findings suggest that the gluteus medius muscle of female runners with ITBS does not demonstrate gross strength impairments but does demonstrate less resistance to fatigue. Clinicians should consider implementation of a gluteus medius endurance training regimen into a runner's rehabilitation program.

The relationship between foot arch flexibility and medial-lateral ground reaction force distribution.

BACKGROUND: Overuse running injury susceptibility has previously been associated with the magnitude and slope of ground reaction force profiles, most often in the vertical axis. However, despite the implications of excessive pronation and supination on injury susceptibility, very little research has examined the factors that might affect distribution of force in the medial-lateral directions. RESEARCH QUESTION: The purpose of this study was to consider how foot structure, specifically arch flexibility, affects the distribution of ground reaction force between the medial-lateral and vertical planes of motion. METHODS: Twenty-five participants were classified as having stiff or flexible arches, and three dimensional kinetic data were gathered while the volunteers ran at 7 mph on an instrumented treadmill. A mixed-effects ANOVA was used to analyze the effect of arch flexibility type on distribution of ground reaction force impulse in the medial and lateral directions. RESULTS: The results suggest that individuals with relatively stiff arches experience a greater proportion of ground reaction force in the medial-lateral plane of motion, as compared with those with more flexible arches (p = 0.03). Further, the results suggest that most individuals, regardless of foot structure, experience greater impulse of force in the lateral than in the medial direction (p < 0.01). SIGNIFICANCE: Considering previously explored relationships between ground reaction force, foot pronation/supination, and chronic running injuries, the results of this study suggest that arch flexibility could be used as a criterion for assessing injury susceptibility. Further, conclusions drawn from this study add to the discussion on the pros and cons of training or using devices to increase or restrict arch flexibility while running.

Comprehensive biomechanical characterization of feet in USMA cadets: Comparison across race, gender, arch flexibility, and foot types.

Lower extremity musculoskeletal injuries are common, complex, and costly problems. Literature supports associations between static foot structure and dynamic foot function, as well as between overuse injury and demographic characteristics. Previous studies failed to provide a comprehensive biomechanical foot characteristics of at-risk military personnel. In this study, foot structure, function, and arch height flexibility (AHF) were objectively measured in 1090 incoming cadets (16.3% female, mean age of 18.5years and BMI of 24.5kg/m2) of the United States Military Academy at the start of their training. A Generalized Linear Model with an identity link function was used to examine the effects of race, gender, foot types, and AHF while accounting for potential dependence in bilateral data. Planus and flexible feet independently demonstrated over-pronation, as measured by reduced Center of Pressure Excursion Index (CPEI). When comparing across race, Black participants showed a significantly lower arch height index (AHI), a larger malleolar valgus index (MVI), and a higher prevalence of pes planus (91.7% versus 73.3% overall). However, Asian participants with flexible arches, rather than Black with low arch, displayed over-pronation in gait. Females showed no significant difference in standing AHI and MVI but demonstrated a significantly greater AHF and a reduced CPEI than male participants. This was the first large scale investigation that comprehensively characterized biomechanical foot in a cohort of young at-risk individuals with lower limb musculoskeletal injuries. Long-term goal is to examine the relationship between these biomechanical features and injuries, ultimately to develop effective preventive measures.

Concurrent validity of an automated algorithm for computing the center of pressure excursion index (CPEI).

Center of Pressure Excursion Index (CPEI), a parameter computed from the distribution of plantar pressures during stance phase of barefoot walking, has been used to assess dynamic foot function. The original custom program developed to calculate CPEI required the oversight of a user who could manually correct for certain exceptions to the computational rules. A new fully automatic program has been developed to calculate CPEI with an algorithm that accounts for these exceptions. The purpose of this paper is to compare resulting CPEI values computed by these two programs on plantar pressure data from both asymptomatic and pathologic subjects. If comparable, the new program offers significant benefits-reduced potential for variability due to rater discretion and faster CPEI calculation. CPEI values were calculated from barefoot plantar pressure distributions during comfortable paced walking on 61 healthy asymptomatic adults, 19 diabetic adults with moderate hallux valgus, and 13 adults with mild hallux valgus. Right foot data for each subject was analyzed with linear regression and a Bland-Altman plot. The automated algorithm yielded CPEI values that were linearly related to the original program (R2=0.99; P<0.001). Bland-Altman analysis demonstrated a difference of 0.55% between CPEI computation methods. Results of this analysis suggest that the new automated algorithm may be used to calculate CPEI on both healthy and pathologic feet.

A qualitative study of the experience of lower extremity wounds and amputations among people with diabetes in Philadelphia.

The purpose of this study was to explore perceptions among people with type 2 diabetes about foot ulcers and lower extremity amputations. This was a qualitative observational study utilizing open-ended, semistructured interviews of 39 people with diabetes who were purposively selected because they had either a foot ulcer (n = 19) or a lower extremity amputation (n = 20). Interviews were audio-recorded, deidentified, and entered into NVivo 10.0 for coding and analysis. Our integrated analytic approach combined inductively and deductively derived codes that were applied to all transcripts. Coded data were summarized and examined for patterns. Participants' description of the relationship between diabetes and their foot ulcer or amputation revealed a limited understanding of the disease process. Disruption and loss of independence was expressed whether the person had a foot ulcer or an amputation. Treatment recommendations for foot ulcers were viewed by most as extremely difficult. Amputation was a feared outcome, but some learned to adapt and, at times felt that the amputation enhanced their quality of life. Clinicians have assumed that a focus on limb salvage is preferred over a major amputation. However, because of the complexity of care requiring frequent healthcare provider visits, the frequency of care failure, the frequency of recurrence, and mortality associated with having had a foot ulcer, it may be more appropriate for clinicians to prioritize quality-of-life salvage. Foot ulcer treatment failure may be due to a lack of providers' understanding of the impact of treatment on a patient's life.

The Relationship Between Arch Height and Arch FlexibilityA Proposed Arch Flexibility Classification System for the Description of Multidimensional Foot Structure.

BACKGROUND: The correlation between arch structure and injury may be related to the fact that foot structure influences foot function. Foot structure is often defined by arch height, although arch flexibility may be just as important to form a more complete description. We propose an arch flexibility classification system, analogous to arch height classification, and then use the classification system to examine the relationship between arch flexibility and arch height. METHODS: Arch height index was calculated in 1,124 incoming military cadets, of whom 1,056 had usable data. By measuring arch height during both sitting and standing, a measurement of arch flexibility could also be calculated. These values were used to create five arch flexibility categories: very stiff, stiff, neutral, flexible, and very flexible. The distribution of arch flexibility types among arch height categories was statistically compared. RESULTS: The goodness of fit test showed a disproportionate number of each arch flexibility type in each of the arch height categories (P < .01). The largest proportion of cavus feet was very stiff and the smallest proportion was very flexible. Conversely, the largest proportion of planus feet was very flexible and the smallest proportion was very stiff. CONCLUSIONS: The results of this research support the common belief that cavus feet tend to be very stiff and planus feet tend to be very flexible.

An Investigation of Structure, Flexibility, and Function Variables that Discriminate Asymptomatic Foot Types.

It has been suggested that foot type considers not only foot structure (high, normal, low arch), but also function (overpronation, normal, oversupination) and flexibility (reduced, normal, excessive). Therefore, this study used canonical regression analyses to assess which variables of foot structure, function, and flexibility can accurately discriminate between clinical foot type classifications. The feet of 61 asymptomatic, healthy adults (18-77 years) were classified as cavus (N = 24), rectus (N = 54), or planus (N = 44) using standard clinical measures. Custom jigs assessed foot structure and flexibility. Foot function was assessed using an emed-x plantar pressure measuring device. Canonical regression analyses were applied separately to extract essential structure, flexibility, and function variables. A third canonical regression analysis was performed on the extracted variables to identify a combined model. The initial combined model included 30 extracted variables; however 5 terminal variables (malleolar valgus index, arch height index while sitting, first metatarsophalangeal joint laxity while standing, pressure-time integral and maximum contact area of medial arch) were able to correctly predict 80.7% of foot types. These remaining variables focused on specific foot characteristics (hindfoot alignment, arch height, midfoot mechanics, Windlass mechanism) that could be essential to discriminating foot type.

The effects of fatigue on lower extremity kinematics, kinetics and joint coupling in symptomatic female runners with iliotibial band syndrome.

BACKGROUND: Altered hip and knee kinematics and joint coupling have been documented in runners with iliotibial band syndrome. Symptoms often present themselves after several minutes of running, yet the effect of fatigue warrants further exploration. The purpose of this study was to determine the effect of a run to fatigue in runners with iliotibial band syndrome, as compared to healthy controls. METHODS: Twenty uninjured and 12 female runners with iliotibial band syndrome performed a treadmill run to fatigue. Prior-to and following a run to fatigue, overground running data were collected. Variables of interest included stance phase: peak hip adduction and internal rotation, peak hip abductor and external rotator joint moments and frontal-sagittal plane hip and knee joint coupling. FINDINGS: Fatigue resulted in decreased peak hip adduction angles in injured runners. Fatigue did not affect injured runners differently than controls with respect to the remaining variables. Coupling differences did not exist between healthy and injured runners with respect to the loading or propulsive phases of stance. INTERPRETATION: While clinicians often strengthen hip abductor muscles and provide gait re-training to decrease stance phase hip adduction, our results suggest that, when exerted, female runners with iliotibial band syndrome independently modify their running gait to decrease hip adduction, potentially as a result of pain. Fatigue did not have an effect on the remaining study variables. It is possible that reducing the length of the iliotibial band through minimizing hip adduction reduces pain, but the other variables examined are not sensitive to this phenomenon.

Effects of weight loss on foot structure and function in obese adults: a pilot randomized controlled trial.

OBJECTIVE: To investigate the effects of weight reduction on foot structure, gait, and dynamic plantar loading in obese adults. DESIGN: In a 3-month randomized-controlled trial, participants were randomized to receive either a weight loss intervention based on portion-controlled meals or a delayed-treatment control. PARTICIPANTS: 41 adults (32 F, 9 M) with a mean ± SD age of 56.2 ± 4.7 years and a BMI of 35.9 ± 4.2 kg/m(2). MEASUREMENTS: Arch Height Index (AHI), Malleolar Valgus Index (MVI), spatial and temporal gait parameters, plantar peak pressure (PP) and weight were measured at baseline, 3, and 6 months. RESULTS: The intervention group experienced significantly greater weight loss than did the control group (5.9 ± 4.0 kg versus 1.9 ± 3.2 kg, p = 0.001) after 3 months. There were no differences between the groups in anatomical foot structure or gait. However, the treatment group showed a significantly reduced PP than the control group beneath the lateral arch and the metatarsals 4 (all p values < .05) at 3 months. The change in PP correlated significantly with the change in weight at the metatarsal 2 (r = 0.57, p = 0.0219), metatarsal 3 (r = 0.56, p = 0.0064) and the medial arch (r = 0.26, p < 0.0001) at 6 months. CONCLUSION: This was the first RCT designed to assess the effects of weight loss on foot structure, gait, and plantar loading in obese adults. Even a modest weight loss significantly reduced the dynamic plantar loading in obese adults. However, weight loss appeared to have no effects on foot structure and gait.

Physical performance measurement in persons with patellofemoral osteoarthritis: A pilot study.

BACKGROUND: Patellofemoral osteoarthritis (PFOA) is associated with pain and decreased self-reported function. The impact of PFOA on actual physical performance is currently unknown. OBJECTIVE: To investigate the impact of PFOA on physical performance and pain. METHODS: Eight participants aged 40-65 years with bilateral, symptomatic, radiographic PFOA and 7 age- and gender-matched pain-free control participants without radiographic PFOA were studied. Physical performance was measured with the Timed-Up-and-Go (TUG) and 50-foot Fast-Paced-Walk (FPW) tests. Dependent variables included time to complete the TUG and FPW; pretest-posttest change in pain intensity (TUG and FPW); and self-reports of perceived knee pain, stiffness, and physical function. Data were analyzed with nonparametric statistics. RESULTS: The PFOA group TUG time was longer than the control group (p=0.01). No difference between groups was found for FPW time. Pretest-posttest pain increased for the TUG and FPW in PFOA participants (p< 0.05). The PFOA group reported greater knee pain, stiffness, and less physical function than controls (previous 48 hours) (p < 0.01). CONCLUSIONS: Symptomatic, radiographic PFOA is associated with increased pain during the TUG and FPW tests and longer time required to complete the TUG. The TUG may be a more sensitive test of physical performance in PFOA.

Frontal plane knee and hip kinematics during sit-to-stand and proximal lower extremity strength in persons with patellofemoral osteoarthritis: a pilot study.

Increased joint stress and malalignment are etiologic factors in osteoarthritis. Static tibiofemoral frontal plane malalignment is associated with patellofemoral osteoarthritis (PFOA). Patellofemoral joint stress is increased by activities such as sit-to-stand (STS); this stress may be even greater if dynamic frontal plane tibiofemoral malalignment occurs. If hip muscle or quadriceps weakness is present in persons with PFOA, aberrant tibiofemoral frontal plane movement may occur, with increased patellofemoral stress. No studies have investigated frontal plane tibiofemoral and hip kinematics during STS in persons with PFOA or the relationship of hip muscle and quadriceps strength to these motions. Eight PFOA and seven control subjects performed STS from a stool during three-dimensional motion capture. Hip muscle and quadriceps strength were measured as peak isometric force. The PFOA group demonstrated increased peak tibial abduction angles during STS, and decreased hip abductor, hip extensor, and quadriceps peak force versus controls. A moderate inverse relationship between peak tibial abduction angle and peak hip abductor force was present. No difference between groups was found for peak hip adduction angle or peak hip external rotator force. Dynamic tibiofemoral malalignment and proximal lower extremity weakness may cause increased patellofemoral stress and may contribute to PFOA incidence or progression.

Effect of shoe flexibility on plantar loading in children learning to walk.

BACKGROUND: In a previous pilot study of "cruisers" (nonindependent ambulation), "early walkers" (independent ambulation for 0-5 months), and "experienced walkers" (independent ambulation for 6-12 months), developmental age significantly affected the children's stability when walking and performing functional activities. We sought to examine how shoe structural characteristics affect plantar pressure distribution in early walkers. METHODS: Torsional flexibility was evaluated in four shoe designs (UltraFlex, MedFlex, LowFlex, and Stiff based on decreasing relative flexibility) with a structural testing machine. Plantar pressures were recorded in 25 early walkers while barefoot and shod at self-selected walking speeds. Peak pressure was calculated over ten masked regions for the barefoot and shod conditions. RESULTS: Torsional flexibility, the angular rotation divided by the applied moment about the long axis of the shoe, was different across the four shoe designs. As expected, UltraFlex was the most flexible and Stiff was the least flexible. As applied moment increased, torsional flexibility decreased in all footwear. When evaluating early walkers during gait, peak pressure was significantly different across shoe conditions for all of the masked regions. The stiffest shoe had the lowest peak pressures and the most flexible shoe had the highest. CONCLUSIONS: It is likely that increased shoe flexibility promoted greater plantar loading. Plantar pressures while wearing the most flexible shoe are similar to those while barefoot. This mechanical feedback may enhance proprioception, which is a desirable attribute for children learning to walk.

Reliability of plantar pressure platforms.

Plantar pressure measurement is common practice in many research and clinical protocols. While the accuracy of some plantar pressure measuring devices and methods for ensuring consistency in data collection on plantar pressure measuring devices have been reported, the reliability of different devices when testing the same individuals is not known. This study calculated intra-mat, intra-manufacturer, and inter-manufacturer reliability of plantar pressure parameters as well as the number of plantar pressure trials needed to reach a stable estimate of the mean for an individual. Twenty-two healthy adults completed ten walking trials across each of two Novel emed-x(®) and two Tekscan MatScan(®) plantar pressure measuring devices in a single visit. Intraclass correlation (ICC) was used to describe the agreement between values measured by different devices. All intra-platform reliability correlations were greater than 0.70. All inter-emed-x(®) reliability correlations were greater than 0.70. Inter-MatScan(®) reliability correlations were greater than 0.70 in 31 and 52 of 56 parameters when looking at a 10-trial average and a 5-trial average, respectively. Inter-manufacturer reliability including all four devices was greater than 0.70 for 52 and 56 of 56 parameters when looking at a 10-trial average and a 5-trial average, respectively. All parameters reached a value within 90% of an unbiased estimate of the mean within five trials. Overall, reliability results are encouraging for investigators and clinicians who may have plantar pressure data sets that include data collected on different devices.

Foot Type Biomechanics Part 2: are structure and anthropometrics related to function?

BACKGROUND: Many foot pathologies are associated with specific foot types. If foot structure and function are related, measurement of either could assist with differential diagnosis of pedal pathologies. HYPOTHESIS: Biomechanical measures of foot structure and function are related in asymptomatic healthy individuals. METHODS: Sixty-one healthy subjects' left feet were stratified into cavus (n=12), rectus (n=27) and planus (n=22) foot types. Foot structure was assessed by malleolar valgus index, arch height index, and arch height flexibility. Anthropometrics (height and weight), age, and walking speed were measured. Foot function was assessed by center of pressure excursion index, peak plantar pressure, maximum force, and gait pattern parameters. Foot structure and anthropometric variables were entered into stepwise linear regression models to identify predictors of function. RESULTS: Measures of foot structure and anthropometrics explained 10-37% of the model variance (adjusted R(2)) for gait pattern parameters. When walking speed was included, the adjusted R(2) increased to 45-77% but foot structure was no longer a factor. Foot structure and anthropometrics predicted 7-47% of the model variance for plantar pressure and 16-64% for maximum force parameters. All multivariate models were significant (p<0.05), supporting acceptance of the hypothesis. DISCUSSION AND CONCLUSION: Foot structure and function are related in asymptomatic healthy individuals. The structural parameters employed are basic measurements that do not require ionizing radiation and could be used in a clinical setting. Further research is needed to identify additional predictive parameters (plantar soft tissue characteristics, skeletal alignment, and neuromuscular control) and to include individuals with pathology.

Foot type biomechanics part 1: structure and function of the asymptomatic foot.

BACKGROUND: Differences in foot structure are thought to be associated with differences in foot function during movement. Many foot pathologies are of a biomechanical nature and often associated with foot type. Fundamental to the understanding of foot pathomechanics is the question: do different foot types have distinctly different structure and function? AIM: To determine if objective measures of foot structure and function differ between planus, rectus and cavus foot types in asymptomatic individuals. METHODS: Sixty-one asymptomatic healthy adults between 18 and 77 years old, that had the same foot type bilaterally (44 planus feet, 54 rectus feet, and 24 cavus feet), were recruited. Structural and functional measurements were taken using custom equipment, an emed-x plantar pressure measuring device, a GaitMat II gait pattern measurement system, and a goniometer. Generalized Estimation Equation modeling was employed to determine if each dependent variable of foot structure and function was significantly different across foot type while accounting for potential dependencies between sides. Post hoc testing was performed to assess pair wise comparisons. RESULTS: Several measures of foot structure (malleolar valgus index and arch height index) were significantly different between foot types. Gait pattern parameters were invariant across foot types. Peak pressure, maximum force, pressure-time-integral, force-time-integral and contact area were significantly different in several medial forefoot and arch locations between foot types. Planus feet exhibited significantly different center of pressure excursion indices compared to rectus and cavus feet. CONCLUSIONS: Planus, rectus and cavus feet exhibited significantly different measures of foot structure and function.

Consequences of pediatric obesity on the foot and ankle complex.

BACKGROUND: Anthropometric status can influence gait biomechanics, but there is relatively little published research regarding foot and ankle characteristics in the obese pediatric population. We sought to compare the structural and functional characteristics of the foot and ankle complex in obese and non-obese children. METHODS: Twenty healthy children (ten obese and ten normal weight) were recruited for a cross-sectional research study. Anthropometric parameters were measured to evaluate active ankle dorsiflexion, arch height (arch height index, arch rigidity index ratio, and arch drop), foot alignment (resting calcaneal stance position and forefoot-rearfoot alignment in unloaded and loaded positions), and foot type (malleolar valgus index). Independent t tests determined significant differences between groups for all assessed parameters. Statistical significance was set at P < .0125. RESULTS: Compared with non-obese participants, obese participants had significantly greater arch drop (mean ± SD: 5.10 ± 2.13 mm versus 2.90 ± 1.20 mm; P =.011) and a trend toward lower arch rigidity index ratios (mean ± SD: 0.92 ± 0.03 versus 0.95 ± 0.02; P = .013). In addition, obese participants had significantly less active ankle dorsiflexion at 90° of knee flexion versus non-obese participants (mean ± SD: 19.57 ± 5.17 versus 29.07 ± 3.06; P < .001). No significant differences existed between groups for any other anthropometric measurements. CONCLUSIONS: The decreased active ankle dorsiflexion in the obese group can increase foot contact for a longer period of the stance phase of gait. Obese participants also presented with a more flexible foot when bearing weight.

The effect of foot structure on 1st metatarsophalangeal joint flexibility and hallucal loading.

The purpose of our study was to examine 1st metatarsophalangeal (MTP) joint motion and flexibility and plantar loads in individuals with high, normal and low arch foot structures. Asymptomatic individuals (n=61), with high, normal and low arches participated in this study. Foot structure was quantified using malleolar valgus index (MVI) and arch height index (AHI). First MTP joint flexibility was measured using a specially constructed jig. Peak pressure under the hallux, 1st and 2nd metatarsals during walking was assessed using a pedobarograph. A one-way ANOVA with Bonferroni-adjusted post hoc comparisons was used to assess between-group differences in MVI, AHI, early and late 1st MTP joint flexibility in sitting and standing, peak dorsiflexion (DF), and peak pressure under the hallux, 1st and 2nd metatarsals. Stepwise linear regression was used to identify predictors of hallucal loading. Significant between-group differences were found in MVI (F(2,56)=15.4, p<0.01), 1st MTP late flexibility in sitting (F(2,57)=3.7, p=0.03), and standing (F(2,57)=3.7, p=0.03). Post hoc comparisons demonstrated that 1st MTP late flexibility in sitting was significantly higher in individuals with low arch compared to high arch structure, and that 1st MTP late flexibility in standing was significantly higher in individuals with low arch compared to normal arch structure. Stepwise regression analysis indicated that MVI and 1st MTP joint early flexibility in sitting explain about 20% of the variance in hallucal peak pressure. Our results provide objective evidence indicating that individuals with low arches show increased 1st MTP joint late flexibility compared to individuals with normal arch structure, and that hindfoot alignment and 1st MTP joint flexibility affect hallucal loading.