In-shoe Pressure Distribution Research Articles

Arch-support foot-orthoses normalize dynamic in-shoe foot pressure distribution in medial tibial stress syndrome

Excessive foot pronation during gait is a risk factor in medial tibial stress syndrome (MTSS). Arch-support foot-orthoses are commonly used to manage overpronation, but it is unknown whether it is effective to manage MTSS. The present study investigated the effects of bilateral foot orthoses during running on dynamic foot-pressure distribution patterns in recreational runners with MTSS. Fifty novice (started within the last 4 months) runners diagnosed with MTSS (20.7 ± 2.2 years; 71.1 ± 8.6 kg; 1.78 ± 0.07 m; mean ± SD) and 50 anthropometrically-matched healthy novice runners (21.9 ± 2.4 years; 71.4 ± 8.8 kg; 1.73 ± 0.07 m) participated in this study. The dynamic foot-pressure distribution during running with and without bilateral arch-support foot-orthoses was measured using pedobarography. MTSS novice runners have more medially directed pressures during the touchdown phase of the forefoot flat (p = 0.009) and heel off (p = 0.009), and a lateral pressure distribution during forefoot push-off phase (p = 0.007) during running than healthy runners. When using the arch-support foot-orthoses the foot-pressure distribution during all phases was not significantly different from that seen in participants without MTSS. These findings indicate that during running the medial shift of foot pressures during the loading response phase and the lateral shift during the propulsion phase of foot roll-over in MTSS are effectively corrected by using arch-support foot-orthoses. The use of such arch-support orthoses may thus be an effective tool to normalize foot-pressure distribution patterns during running, indicating the potential to treat and prevent MTSS in recreational runners.

Midsole Stiffness Influences Plantar Loading During Double Leg Landings In Basketball Players

Lateral foot (LF) loading has been purported to relate to increased risk of fifth metatarsal fractures in an athletic population. In a basketball population, Jones fractures are a debilitating injury sustained to the LF. Increasing the shoe stiffness or adding custom orthoses have been previously used to help control loading and as an intervention to decrease risk of stress fractures on the fifth metatarsal. Conflicting results on LF loading have been found when increasing stiffness during athletic performance. PURPOSE:To examine the effects of midsole stiffness on lateral plantar loading during a drop vertical jump (DVJ). METHODS:Twenty high school and collegiate basketball players volunteered to participate in the current study (height 185.9 ± 6.2cm, mass 80.6 ± 9.2kg, age 18.0 ± 1.84yrs). Each subject was fitted for the appropriately sized basketball shoe. One pair of shoes was modified with a fiberglass plate placed under the insole to increase midsole stiffness. The shoe conditions were blinded and randomly assigned to each subject. During the DVJ, subjects stood on a 30 cm box and dropped off with both feet leaving the box at the same time. Upon immediate landing, they completed a maximum vertical jump. A flexible in-shoe pressure distribution measuring insole was used in the right side and sampled at 200Hz. Separate repeated measures analysis of variance (ANOVA) determined the relative loading differences in shoe stiffness during the DVJ in 9 foot regions (p<0.05. RESULTS:The control (less stiff) shoe had greater relative loading in the central forefoot (control: 15.2 ± 4.2%, stiff: 13.9 ± 4%, p=0.04) and lesser toes (control: 12.6 ± 4.1%, stiff: 10.8 ± 3.5%, p=0.01) regions during the landing phase. However, the stiff footwear had greater relative load in the lateral midfoot compared to the control shoe (control: 10.3 ± 5.7%, stiff: 11.7 ± 6.6%, p=0.01). CONCLUSIONS:The results indicate that greater shoe stiffness increases plantar loading on the lateral midfoot which coincides with the proximal head of the fifth metatarsal. Increasing shoe stiffness should be done cautiously as increased loading on the LF may exist. Whether this increased loading is present during other basketball tasks should be determined. The authors would like to acknowledge funding support from adidas International, Inc.

Forefoot Loading With Step Rate Changes in Recreational Runners

Recreational runners benefit from increased physical activity but often sustain overuse lower extremity injuries. To reduce risk of injury, gait retraining to increase step rates have been developed that decrease peak vertical force and knee loading. However, runners at risk of overuse injuries in the metatarsals may not experience reduced forefoot loading with increased cadence. PURPOSE: To determine if an alteration in cadence would affect forefoot loading during treadmill running in recreational runners. METHODS: Fifteen recreational runners (height 168.32±9.25 cm, 68.16±11.8 kg, age 20.69± 0.83 years) who run ≥10 miles a week were selected. Individuals ran at a self-selected running speed while their preferred step rate was calculated. Three cadence levels were randomly assigned to each subject (+10% -10%, and normal cadence). Subjects were then instructed to match their foot strikes with the sound of a metronome. In-shoe pressure distribution insoles were used to determine force time integral (FTI) within the medial, central and lateral forefoot. Repeated measures ANOVA were used to determine step rate differences in loading (p<0.05). RESULTS: A main effect of step rate was found for FTI in the medial (p=0.009) and central (p=0.003) forefoot regions. Specifically, FTI was less in the -10% compared to +10% condition in the medial (-10%: 4.7±1.2%BW·s, +10%: 4.3±1.3%BW·s; p=0.008) and central (-10%: 5.4±0.8%BW·s, +10%: 5.1±0.8%BW·s; p=0.007) forefoot. Conclusion: Our data, with a larger 10% step rate modification compared to 5% change, support previous work indicating reduced medial and central forefoot loading (Wellenkotter 2014). Similarly, the lateral forefoot did not result in significant changes in loading. Interventions to reduce lateral forefoot loading should be investigated in patients returning from or prone to lateral forefoot injuries.

Effects of Contralateral Versus Ipsilateral Cane Use on Gait in People with Knee Osteoarthritis

ObjectiveTo compare the immediate effects of contralateral versus ipsilateral cane use on spatiotemporal gait parameters and peak vertical ground force in overweight or obese adults with symptomatic knee osteoarthritis (OA). DesignProspective observational study. SettingAn academic tertiary Veterans Affairs Healthcare Center. ParticipantsThirty-eight overweight or obese subjects with symptomatic knee OA who had not used a cane for the past 30 days. MethodsSpatiotemporal gait data were obtained with an optical motion capture system while subjects walked without a cane, with a cane contralateral to the more painful lower limb, or with a cane ipsilateral to the more painful lower limb at self-selected speeds. An in-shoe dynamic pressure distribution system was used to measure the vertical ground reaction force. Main Outcome MeasurementsSpatiotemporal measures of gait and peak vertical ground reaction force on both lower limbs were recorded for each walking condition: no cane, contralateral cane, and ipsilateral cane. ResultsWalking with a cane either contralateral or ipsilateral to the more symptomatic limb led to significant reductions in gait velocity (14%-16%), cadence (12%-14%), and peak vertical ground reaction force (normalized for body weight; 11%-12%) on the more painful lower limb compared with walking unaided (P < .05). There were no significant differences in the peak vertical ground reaction force on either lower limbs when comparing walking with a cane contralateral to the more painful limb or walking with a cane ipsilateral to the more painful limb. Subjects also experienced a significant decrease in gait velocity with contralateral or ipsilateral cane use compared with walking without a cane; the lower walking speed was due to a decrease in cadence. ConclusionsThese results support the prescription of a single-point cane to offload a lower limb with painful knee OA by holding the cane either ipsilateral or contralateral to the more painful lower limb.

Biomechanical and functional indicators in male semiprofessional soccer players with increased hip alpha angles vs. amateur soccer players

BackgroundFemoroacetabular impingement (FAI) is predominant in young male athletes, but not much is known about gait differences in cases of increased hip alpha angles. In our study, the hip alpha angle of Nötzli of soccer players was quantified on the basis of magnetic resonance imaging (MRI) with axial oblique sequences. The aim of the current study was to compare the rearfoot motion and plantar pressure in male semiprofessional soccer players with increased alpha angles to age-matched amateur soccer players.MethodsIn a prospective analysis, male semiprofessional and amateur soccer players had an MRI of the right hip to measure the alpha angle of Nötzli. In a biomechanical laboratory setting, 14 of these participants in each group ran in two shoe conditions. Simultaneously in-shoe pressure distribution, tibial acceleration, and rearfoot motion measurements of the right foot were performed.ResultsIn the semiprofessional soccer group, the mean value of the alpha angle of group was 55.1 ± 6.58° (range 43.2-76.6°) and 51.6 ± 4.43° (range 41.9-58.8°) in the amateur group. In both shoe conditions, we found a significant difference between the two groups concerning the ground reaction forces, tibial acceleration, rearfoot motion and plantar pressure parameters (P < 0.01, P < 0.05, P = 0.04). Maximum rearfoot motion is about 22% lower in the semiprofessional group compared to the amateur group in both shoe conditions.ConclusionsThis study confirmed that semiprofessional soccer players with increased alpha angles showed differences in gait kinematics compared to the amateur group. These findings support the need for a screening program for competitive soccer players. In cases of a conspicuous gait analysis and symptomatic hip pain, FAI must be ruled out by further diagnostic tests.

1P1-E03 靴内部における剪断力・圧力の同時測定法の開発(看護とメカトロニクス)

1P1-E03 靴内部における剪断力・圧力の同時測定法の開発(看護とメカトロニクス)

Anterior Cruciate Ligament Tear in an Athlete: Does Increased Heel Loading Increase ACL Injury Risk? A Case Report

PURPOSE: Anterior cruciate ligament (ACL) rupture is a common athletic injury in American football. The lower extremity biomechanics related to increased ACL injury risk are not completely characterized. In this case report, we describe an athlete previously tested for in-shoe loading patterns on artificial turf who subsequently went on to non-contact ACL rupture on the same surface. METHODS: The patient had previously undergone in-shoe foot loading pattern analysis as part of another study. Seventeen male subjects were fitted with a football specific molded cleat and tested while cutting and running through a pre-set course. Flexible in-shoe pressure distribution measuring insoles were inserted in the right cleat. The results were then analyzed as previously reported.Figure: Caption not provided.RESULTS: While in a football scrimmage, a 17 year-old Caucasian male football player suffered a non-contact injury to the right knee. The injury occurred while the athlete attempted to "turn the corner" on a sweep which was similar to the side step cutting task performed previously. Magnetic resonance imaging showed an ACL rupture, lateral meniscal tear, and bone contusion of the lateral tibial plateau. Arthroscopy confirmed the ACL rupture and complex irreparable posterolateral meniscus tear. This injury occurred in an athlete with foot and heel loading patterns well above one standard deviation from mean, indicative of flat-foot landing. CONCLUSIONS: This report suggests that flatfoot tendency in running and cutting maneuvers might lead to an increased risk of ACL injury. Further studies should attempt to identify those athletes with increased flatfoot landing patterns and screen them for relative injury risk.

In-shoe pressure distribution in “unstable” (MBT) shoes and flat-bottomed training shoes: A comparative study

Background Footwear comfort in many clinical situations is dependent on the ability of the ‘shoe’ to redistribute plantar pressure. Offloading the metatarsal heads may be achieved by fitting an insole, but recently a new design of shoe with a curved under sole (Masai Barefoot Technology ® or “MBT shoe”) has been advocated. The aim of this study was to directly assess the effect of such shoes on gait pattern. Methods Normal subjects were recruited and asked to walk sequentially in (a) flat-soled training shoes and (b) midfoot bearing shoes (MBT shoe). Mean and peak pressures in four anatomically defined areas of the foot, and the total area of sole contact were measured electronically by an in-shoe system (Pedar Ltd., UK). Principal results Standing in the Masai shoes resulted in a 21% lesser peak pressure under the midfoot and an 11% lesser peak pressure under the heel in comparison to the figures found when patients wore their training shoes. There was a 76% compensatory increase in pressure under the toes. In essence there was a significant shift in pressure towards the front of the foot.

Comparison of in-shoe foot loading patterns on natural grass and synthetic turf

Synthetic playing surfaces with rubber or sand infill are now used on many athletic fields such as soccer, football and rugby. Although these surfaces may come closer to the mechanical characteristics of a true grass playing surface than the older turf designs, their potential effects on lower extremity biomechanics and related injury rates necessitate further study. The purpose of this study was to examine the effects of two surfaces (natural grass versus turf) on in-shoe foot loading patterns during cutting. Seventeen male football players were tested on a slalom course. An in-shoe pressure distribution measurement insole was used in the right shoe (14 stud, molded cleat) of each athlete. Individual cutting steps were extracted from each slalom trial and peak pressure and relative load calculated in nine distinct plantar regions of the foot. The turf condition had significantly higher peak pressures within the central forefoot (turf: 646.6+/-172.6 kPa, grass: 533.3+/-143.4 kPa, P=0.017) and lesser toes (turf: 429.3+/-200.9 kPa, grass: 348.1+/-119.0 kPa, P=0.043) compared to grass. In contrast, the relative load within the medial forefoot (turf: 27.2+/-5.3%, grass: 30.2+/-6.6%, P=0.031) and lateral midfoot (turf: 3.4+/-1.8%, grass: 4.1+/-2.3%, P=0.029) were higher during the grass condition. No differences between the grass and turf were found in maximal effort sprint times performed prior to the testing trials. This study demonstrates that playing surface significantly affects plantar loading during sport related activities. Further epidemiological investigation is warranted to determine the effects of playing surfaces on sport specific injury mechanisms.

Heel to toe motion characteristics in Parkinson patients during free walking

Objective. Plantar pressures of Parkinson patients in a mild or moderate stage of the disease were analyzed in order to determine characteristics of the heel to toe motion of the foot in Parkinson patients during free walking. Design. Pressure sensitive insoles were used to quantify the in-shoe pressure distribution for 24 patients with Parkinson's disease and for 24 age-matched healthy adults. Peak plantar pressures, relative loads and the variability of relative loads were analyzed for 10 different anatomical foot areas. Inferential statistics and regression analyses were performed to compare subject groups and to relate pressure data to a clinical score (Webster). Background. It is well-known that Parkinson patients experience disorders of balance, posture and gait. Recent studies revealed that Parkinson patients show abnormalities in foot strike during walking. However, only little is known about the heel to toe motion of the foot in Parkinson patients in compensating for instability during walking. Results. Parkinson patients show significant changes in foot loading behavior. Parkinson patients have a reduced impact at heel strike. This mechanism was found to be related to the severity of the disease. Furthermore, Parkinson patients show a trend towards higher relative loads in the forefoot regions combined with a load shift towards medial foot areas. These mechanisms are highly stereotypical. Conclusion. Parkinson patients, even in a mild or moderate stage of the disease, show significant changes in heel to toe motion of the foot during free walking. The characteristics of Parkinsonian gait are probably caused by adaptive mechanisms of the patients to avoid unsteadiness during walking. Relevance The results of this study revealed that Parkinson patients have characteristic heel to toe motion pattern. The determination of the foot-loading pattern using plantar pressure measurement may be used as a valuable tool for diagnostic, treatment and rehabilitation purposes. Furthermore, the strategy of the forefoot control in gait of Parkinson patients should be considered in Parkinsonian research.

The influence of cadence and power output on force application and in-shoe pressure distribution during cycling by competitive and recreational cyclists

The aim of this study was to determine the response of cyclists to manipulations of cadence and power output in terms of force application and plantar pressure distribution. Two groups of cyclists, 17 recreational and 12 competitive, rode at three nominal cadences (60, 80, 100 rev min -1 ) and four power outputs (100, 200, 300, 400 W) while simultaneous force and in-shoe pressure data were collected. Two piezoelectric triaxial force transducers mounted in the right pedal measured components of the pedal force and orientation, and a discrete transducer system with 12 transducers recorded the in-shoe pressures. Force application was characterized by calculating peak resultant and peak effective pedal forces and positive and negative impulses. In-shoe pressures were analysed as peak pressures and as the percent relative load. The force data showed no significant group effect but there was a cadence and power main effect. The impulse data showed a significant three-way interaction. Increased cadence resulted in a decreased positive impulse, while increased power output resulted in an increased impulse. The competitive group produced less positive impulse but the difference became less at higher cadences. Few between-group differences were found in pressure, notable only in the pressure under the first metatarsal region. This showed a consistent pattern of in-shoe pressure distribution, where the primary loading structures were the first metatarsal and hallux. There was no indication that pressure at specific sites influenced the pedal force application. The absence of group differences indicated that pressure distribution was not the result of training, but reflected the intrinsic relationship between the foot, the shoe and the pedal.

Lower limb muscle dysfunction may contribute to foot ulceration in diabetic patients

Objectives. To investigate the relationship between in-shoe plantar foot pressure and the co-ordinated activity of five lower limb muscles of diabetic patients, who are known to have a higher risk of foot morbidity. Design. A portable six channel electromyographic system has been designed, developed and synchronised in real time with a 16 channel piezoelectric transducer in-shoe pressure measuring device, Gaitscan. Background. So far, no one has tried to establish a relationship between in-shoe foot pressure distribution and muscle activity of the lower limb in diabetes. The measurement of phasic muscle activity has been related to foot pressure and compared to a control group of normal volunteers. Methods. Twenty nine diabetic subjects and 22 healthy non-diabetic volunteers have been studied by recording electromyography of lower leg muscles and in-shoe foot pressure measurements simultaneously. Results. In diabetic subjects, the period of contact pressure was greater than in normal control subjects ( P < 0.003). The initial forefoot time to contact with the ground was shorter in diabetics when compared to controls, indicating a faster forefoot contact. Of the dorsiflexor muscles, the Anterior Tibialis, normally contracting eccentrically at heel strike, was subject to a measurable delay in the initiation of contraction, of mean difference of 180 ms ( P < 0.001), in diabetic subjects when compared to the normal controls. Conclusions. The late firing of Tibialis Anterior means that its normal modulating role in lowering the foot to the ground after heel strike through eccentric contraction is disturbed. The result is that the foot reaches the foot flat stage in a less ordered manner, subjecting it to high plantar pressures. Relevance The results obtained may assist in planning realignment procedures of the foot and help prevent development of ulcers on the sole of the foot in high risk diabetic subjects.

Perceptual and biomechanical variables for running in identical shoe constructions with varying midsole hardness

Objective. Perceptual ratings of mechanical variables were compared with biomechanical variables that are related to running injuries. Design. Eight identical running shoes with a relatively close range of midsole hardness were used. Ground reaction force (GRF), in-shoe pressure distribution and rearfoot motion were measured during running. Perceptual ratings were obtained after the running trials. Background. Previous studies reported high correlations between cushioning perception and biomechanical variables for shoes that featured large differences in midsole hardness. Methods. A 15-point categorical rating scale was used to judge impact severity, pressure magnitude and rearfoot motion in running. Rating scores were compared with biomechanical variables (GRF, pressure distribution and pronation values) using regression analyses. Results. Regression analyses revealed high relations between different biomechanical variables and the perception scores. The best relation to perception was analysed for the median power frequency of the vertical GRF ( r 2 = 0.97). A negative correlation ( r 2 = 0.54) between the first impact of GRF and the perception of impact severity could be revealed. Conclusion. The present study suggests that the body's sensory system seems to differentiate well between impacts of different frequency content. Based on perceptual abilities, subjects adapt their running style to avoid high heel impacts.

Spatial resolution in plantar pressure measurement

Peaks of pressure under the foot are of significance to the understanding and limitation of damage to plantar tissues. At present, many of the pressure measuring systems use a matrix of discrete transducer cells which each register the average pressure over their surface, and whose dimensions are such that they limit the accurate representation of the true peak pressure. The spatial filtering effect is investigated in this paper by analytical deduction from a pedobarographic record of high spatial resolution. For a barefoot diabetic patient who presents sharp peaks of pressure in the metatarsal region, the effect of notional cell dimensions is investigated through analysis of a typical record and shown to constitute a potentially significant error for cells of the dimensions of those in common use. The average pressure read from a transducer of area 100 mm 2 may be of the order of 60–70% of the true peak in barefoot standing, although this depends on the sharpness of the peaks. Errors are decreased when the more even in-shoe pressure distribution is considered.

In-Shoe Pressure Distribution for Running in Various Types of Footwear

Discrete pressure sensors were used to examine the influence of shoe construction on the local forces under the foot. Measurements were performed at eight locations under the feet of 22 subjects wearing 19 different models of running shoes. Mechanical properties of shoe soles were assessed with an impacter device. Pressure distribution, ground reaction force, and acceleration data were collected simultaneously during running at 3.3 m/s. Early lateral loading of the rearfoot was followed by increasing medial forefoot loads. In the later phase of pushoff the load was almost entirely carried by the first metatarsal head and the hallux. Substantial differences in plantar foot pressures and relative loads among shoe models indicated that footwear construction has a substantial influence on the loading behavior of the foot during ground contact. Finally, the chosen sensor locations under the foot were found to be adequate to estimate the vertical ground reaction force.

Rearfoot Motion and Pressure Distribution Patterns during Running in Shoes with Varus and Valgus Wedges

The purpose of this study was to investigate the influence of 8° varus and vaigus shoe modifications on the foot mechanics in overground running. Twenty male subjects performed eight rearfoot running trials in three shoe conditions. Ground reaction forces, tibial accelerations, rearfoot motion, and in-shoe pressure distribution data were collected simultaneously. Between footwear conditions, force and acceleration parameters were found to be significantly different. Compared to the neutral shoe, maximum pronation and pronation velocity were reduced for the varus and increased for the vaigus shoes. Higher lateral rearfoot loads and an increased contribution of the first ray in the forefoot could be evaluated for the vaigus shoe. In contrast, a larger contribution of the medial midfoot and the fifth metatarsal head was observed for the varus shoe. The relative load analysis from the pressure distribution measurements provided additional information about the behavior of the foot in response to major changes in shoe construction.

In-shoe heel pressure distribution and impact ground reaction force during running

In-shoe heel pressure distribution and impact ground reaction force during running

Criteria for biomechanical tests for athletic shoes

In recent years, comparative sport shoe tests have resulted in an improvement of athletic footwear quality. Examples demonstrate the value and the limits of material tests, biomechanical investigations and subjective wear test evaluations. Biomechanical experiments have the primary goal to analyse sports shoe function with regard to shoe properties to prevent injuries. Rear foot pronation and supination measurements, in-shoe pressure distribution analyses, and the registration of ground reaction forces as well as tibial accelerations are valuable in the process of biomechanical evaluation. Material tests can be used to determine production quality between shoes and midsole material deterioration in used shoes. Wear tests with subjective evaluation are necessary for the judgement of shoe properties (e.g., shoe fit) which cannot be measured by biomechanical or material test methods.

In-shoe pressure distribution in cycling and running shoes during steady-rate cycling

In-shoe pressure distribution in cycling and running shoes during steady-rate cycling

In-shoe pressure distribution measurements in the triple jump

In-shoe pressure distribution measurements in the triple jump