Changes In Plantar Pressure Distribution Research Articles

Evaluation of therapeutic benefits of botulinum toxin for foot dystonia associated with Parkinson's disease

BackgroundFoot dystonia occurs in patients with Parkinson's disease (PD) and leads to pain, malformation, and difficulty with walking. Botulinum toxin injections may be effective for foot dystonia, but the extent of improvement and effects on motor function are unclear. MethodsIn this study, we performed botulinum toxin injections for foot dystonia in 25 patients with PD. At 3 weeks and 3 months post-infection, we assessed changes in plantar pressure distribution utilizing the Pressure Plate system; dystonia using the Modified Ashworth Spasm score; pain using the visual analog scale (VAS) score; and lower extremity function using the Calf-raise Senior (CRS) test, Timed Up and Go (TUG) test, and gait parameters (eg, stride length, step length). ResultsWe found improved Modified Ashworth Spasm score (p < 0.01) and VAS score (p < 0.01) post-injection. CRS test score (3 weeks, p = 0.006; 3 months, p = 0.068), stride length (3 weeks, p = 0.012; 3 months, p = 0.715), and step length (3 weeks, p = 0.011; 3 months, p = 0.803) also improved. Plantar pressure distribution improved after botulinum toxin injection (metatarsal 1, 3 weeks, p = 0.031; 3 months, p = 0.144; metatarsal 2, 3 weeks, p = 0.049; 3 months, p = 0.065; metatarsal 3, 3 weeks, p = 0.002; 3 months, p = 0.017; metatarsal 4, 3 weeks, p = 0.017; 3 months, p = 0.144; medial heel, 3 weeks, p = 0.01; 3 months, p = 0.395; lateral heel, 3 weeks, p = 0.035; 3 months, p = 0.109). ConclusionBotulinum toxin injection for foot dystonia in patients with PD can reduce spasms and pain and normalize plantar pressure distribution, which improves balance and lower extremity function.

Effect of orthopedic insoles on spinal deformity and walking in adolescents with idiopathic scoliosis summary.

To observe the effects of scoliosis-specific exercise therapy combined with braces and orthopedic insoles on improved spinal deformity and walking ability in adolescents with idiopathic scoliosis (AIS). From September 2019 to September 2020, 60 outpatient AIS patients were distributed into brace group (n = 30) at random and brace combined orthopedic insole group (n = 30). Both groups underwent brace dryness, and the observation group used scoliosis-specific exercise therapy combined with brace therapy, and on this basis, orthopedic insole intervention was added for 8 h per day for 2 months. At the same time, 20 adolescents of the same age with normal spinal development were recruited as a healthy group. GaitScan instruments were used to collect gait and plantar pressure measurements from study subjects. First, the gait and plantar pressure data of AIS patients and healthy groups were compared horizontally to ascertain the abnormal indicators, and then the spinal deformity and the above abnormal indicators were compared between the brace group and the brace combined orthopedic insole group. The plantar pressure center drift index (CPEI) in the AIS group was higher than that in the healthy group (F = 3.120, P < 0.05), and there were significant differences in the ratio of medial and lateral heel pressure (M/l) and total foot pressure (P < 0.05) between the AIS group and the healthy group, and no noticeable variations were found in the support phase period, walking speed, and proportion of each phase (P > 0.05). After treatment, the Cobb angle was significantly reduced in both the brace group and the brace combined with orthopedic insole group (P < 0.05), and there was no significant difference between the groups (P > 0.05). There were no significant changes in the pressure ratio of CPEI, M/l and bilateral full foot in the brace group (P > 0.05). The CPEI decreased in the brace combined with orthopedic insole group (P < 0.05), and the pressure ratio of M/l and bilateral full foot tended to 1 (P < 0.05), and was better than that in the brace group (P < 0.05). Patients with AIS may have local and worldwide asymmetric changes in plantar pressure distribution. The addition of orthopedic insoles has limited effect on improving scoliosis deformity in patients with AIS, but it can effectively improve the abnormal biomechanics of patients with AIS, so that the patient's force tends to be balanced.

Bipedal Static Supination and Dynamic Forefoot Loading Characteristics in Taiwanese College Badminton Players: A Cross-Sectional Study.

Badminton is a unilateral sport that involves repetitive jumping, lunging and quick changes of direction with the lower limb, thus, plantar pressure profiles and foot postural profiles are critical to maintaining balance and coordination. The purpose of this study was to explore the characteristics of static and dynamic plantar pressure profiles with rearfoot posture in elite and recreational badminton players as well as assess the transitional changes of plantar loads between static and dynamic states. A cross-sectional survey was conducted among 65 college-level elite male badminton players (mean age: 20.2 ± 1.2 years; mean height: 177.4 ± 4.6 cm; mean weight: 72.6 ± 4.6 kg) and 68 recreational badminton players of the same gender (mean age: 19.9 ± 0.8 years; mean height: 170.3 ± 3.9 cm; mean weight: 67.7 ± 3.2 kg). The JC Mat was used to evaluate the arch index (AI), plantar pressure distribution (PPD), centers of gravity, and the characteristics of the footprint. Static foot posture was determined by examining the rearfoot alignment. Both groups' AI fell within the normal range. The static plantar loads of the elite group were distributed at the bipedal lateral part of longitudinal arches and heels (p < 0.01), while the right foot experienced higher centers of gravity (p < 0.05). The elite group's static rearfoot postural alignment exhibited a higher degree of rearfoot varus than the recreational group (p < 0.05). In addition, the elite group's dynamic plantar loads were mainly exerted at the medial and lateral metatarsals of both feet (p < 0.05). During the transition state, the recreational group's plantar loads were mainly shifted to the bipedal lateral part of metatarsals and heels (p < 0.05), whereas the elite group's bipedal lateral longitudinal arches as well as the medial and lateral heels experienced a reduction in plantar loads (p < 0.01). For elite badminton players, the findings revealed a possible connection among the static supinated foot, centers of gravity tending towards the right foot, and increased forefoot plantar loads in the dynamic state. The finding merits further exploration of the possible links between transitional changes in plantar pressure distribution in both states and related foot injuries resulting from intense competition and regular training in badminton.

Comparison of Walking Quality Variables between End-Stage Osteonecrosis of Femoral Head Patients and Healthy Subjects by a Footscan Plantar Pressure System.

Background and Objectives: Osteonecrosis of the femoral head (ONFH) is a progressive disease with a complex etiology and unknown pathogenesis. Gait analysis can objectively assess the functional behavior of the foot, thus revealing essential aspects and influencing factors of gait abnormalities. The aim of this study was to evaluate the differences in spatiotemporal parameters, static and dynamic plantar pressure parameters, and symmetry indices between patients with ONFH and healthy subjects. Materials and Methods: The study population consisted of 31 ONFH patients and 31 healthy volunteers. Gait parameters were obtained from the plantar pressure analysis system for both the ONFH and healthy groups. The symmetry index was calculated according to a formula, including spatiotemporal parameters, static and dynamic plantar pressure distribution, percentage of regional impulse, and percentage of the restricted contact area. Results: Compared with healthy controls, patients with ONFH had slower walking speed, shorter step length and stride length, and increased stride time, stance time, and percentage of stance. patients with ONFH had lower plantar static pressure on the affected side and higher contralateral plantar static pressure during stance than controls. During walking, the peak pressures in all regions on the affected side and the peak pressure in the toe 1 and metatarsal 3 regions on the healthy side were lower in ONFH patients than in controls. The percentage of contact area and regional impulse in the heel of both limbs were higher in ONFH patients than in the control group. The symmetry indexes of stride time, stance time, step length, maximum force, impulse and contacted area were significantly increased in ONFH patients compared to controls, with decreased symmetry. Conclusions: Osteonecrosis of the femoral head leads to characteristic changes in plantar pressure distribution. These changes may be interpreted as an attempt by patients with ONFH to reduce the load on the affected limb. Plantar pressure analysis may assist in the diagnosis of ONFH and can provide an objective quantitative indicator for the assessment of subsequent treatment outcomes.

Influence of handrail height and knee joint support on sit-to-stand movement.

Handrail height and knee joint support both significantly influence sit-to-stand (STS) movement. However, research on the associations between handrail height, knee joint support, and their cumulative effect on STS kinematics and changes in plantar pressure distribution during STS under different handrail heights and knee joint support is still unclear. The main objective of this study was to examine the influence of handrail height and knee joint support on the kinematics and the distribution of plantar pressure in healthy adults during STS. Twenty-six healthy adult subjects aged 23 to 58 years participated in this experiment. The subjects carried out STS movement experiments under 7 conditions: 6 experimental conditions of 3 different heights of handrail, with and without knee joint support, and 1 control condition of standing up naturally. The motions of the markers were recorded using cameras operating at 60 Hz, and total movement time, the percentage of movement time of each phase, trunk tilt angle, joint angle, plantar pressure, and the time from hindfoot to forefoot peak pressure were analyzed and compared. Handrail height significantly influences the percentage of movement time at phase I (P = .015) and the maximum trunk tilt angle (P < .05), knee joint support significantly influences the maximum trunk tilt angle and ankle angle (P = .033), and handrail height and knee joint support have an interaction on the time from hindfoot to forefoot peak pressure (P < .001). Subjects' STS performance was improved with the use of assistant devices but showed particular improvement under the condition of with knee joint support when the handrail height was middle handrail.

Effect of different handrail types and seat heights on kinematics and plantar pressure during STS in healthy young adults.

Handrail type and seat height both significantly influence sit-to-stand (STS) movement. However, research on the associations between handrail type, seat height, and their cumulative effect on STS kinematics and changes in plantar pressure distribution during STS under different handrail types and seat heights is insufficient.The main objective of this study was to investigate the effect of different handrail types and seat heights on the kinematics and plantar pressure in healthy adults during STS.The study was conducted on 26 healthy young adults. Six conditions were tested: low seat (LS) and vertical handrail; LS and horizontal handrail (HH); LS and bilateral handrail; high seat (HS) and vertical handrail; HSHH; HS and bilateral handrail. The movement time, trunk tilt angle, and time from hindfoot to forefoot peak pressure were analyzed and compared.A significant difference was found in handrail type (P < .001) and seat height (P < .02) for the total movement time of STS. A significant difference was also found for the maximum trunk tilt angles (P < .001) in handrail types. There was an interaction between handrail type and seat height for the time from hindfoot to forefoot peak pressure of STS (P = .003).Using HSHH could take less time to accomplish STS movement; it also reduced the maximum trunk tilt angle and thus reduce the risk of falling; the time from hindfoot to forefoot peak pressure when using HSHH was short and subjects could accomplish STS movement easier.

The effect of pre-fabricated insole on plantar pressure distribution in patients with rheumatoid arthritis

BackgroundFoot deformities result in pain and changes in plantar pressure distribution in rheumatoid arthritis (RA) patients. Medical insoles are commonly prescribed for declining pain and modifying foot pressure distribution in these patients. The purpose of this study was to evaluate the effect of a pre-fabricated insole with metatarsal pad and medial longitudinal arch support on plantar pressure distribution in rheumatoid arthritis patients. MethodsFifteen females with RA participated in this study. All patients received a pair of pre-fabricated insoles that were individually modified using metatarsal pads and medial longitudinal arch supports. Mean peak pressure (kPa), maximum force (N), and contact area (cm2) were calculated for the heel, midfoot, metatarsophalangeal joint, and toe regions using the Pedar-X system immediately and after a month follow-up. FindingsIn the heel and metatarsophalangeal joint regions, maximum pressure and force showed a significant reduction in the follow-up assessment (p < 0.05). The comparison showed a significant increase in maximum pressure and force in the midfoot when participants walked with insole compared to without insole condition (p < 0.001). InterpretationUsing a pre-fabricated insole with an individually modified metatarsal pad and medial longitudinal arch support could alter rheumatoid arthritis patients’ plantar pressures after one month of follow-up. This type of insole is simple and inexpensive and showed a significant effect on decreasing pressures under the metatarsal heads.

The Combination of Modified Mitchell’s Osteotomy and Shortening Oblique Osteotomy for Patients with Rheumatoid Arthritis: An Analysis of Changes in Plantar Pressure Distribution

The present study aims to evaluate changes in plantar pressure distribution after joint-preserving surgery for rheumatoid forefoot deformity. A retrospective study was performed on 26 feet of 23 patients with rheumatoid arthritis (RA) who underwent the following surgical combination: modified Mitchell’s osteotomy (mMO) of the first metatarsal and shortening oblique osteotomy of the lateral four metatarsals. Plantar pressure distribution and clinical background parameters were evaluated preoperatively and one year postoperatively. A comparison of preoperative and postoperative values indicated a significant improvement in the visual analog scale, Japanese Society for Surgery of the Foot scale, and radiographic parameters, such as the hallux valgus angle. A significant increase in peak pressure was observed at the first metatarsophalangeal joint (MTPJ) (0.045 vs. 0.082 kg/cm2; p < 0.05) and a significant decrease at the second and third MTPJs (0.081 vs. 0.048 kg/cm2; p < 0.05, 0.097 vs. 0.054 kg/cm2; p < 0.05). While overloading at the lateral metatarsal heads following mMO has been reported in previous studies, no increase in peak pressure at the lateral MTPJs was observed in our study. The results of our study show that this surgical combination can be an effective and beneficial surgical combination for RA patients with mild to moderate joint deformity.

Plantar Pressure Distribution during Standing in Female Patients with Hip Osteoarthritis Who Underwent Total Hip Arthroplasty

Introduction: Assessment of plantar pressure indicates the manner in which the plantar region contacts the ground as the first point in a leg-linked kinetic chain, and receives force from the ground. However, few studies have examined the changes in plantar pressure distribution in patients who underwent Total Hip Arthroplasty (THA) before and after THA, or compared plantar pressure distribution between THA patients and healthy adults. Objective: Plantar pressure distribution in patients with end-stage hip osteoarthritis who undergo THA may be adjusted to that in healthy adults by correcting leg length discrepancy. Herein, our objective was to find out if the plantar pressure distribution during standing differs before and after THA, and between healthy adults and THA patients. Design: Case control study. Setting: Single orthopedic clinic in Japan. Participants: THA patients (n=58; THA group) and healthy adults (n=53; control group). Interventions: Not applicable. Main outcome measure(s): The maximum plantar pressure under each foot measured during standing for 20 s was assessed for location, symmetry, and leg length discrepancy. Results: The distribution plantar pressure in the THA group differed preand postoperatively. The maximum plantar pressure region was the heel in approximately 80% of the patients three months after THA; it was not different in THA patients three months postoperatively and in healthy adults. Patients with asymmetrical maximum plantar pressure regions were those whose postoperative maximum plantar pressure region in the affected leg was the forefoot and those whose maximum plantar pressure region in the affected leg shifted to the heel. The leg length discrepancies decreased significantly after THA. Conclusions: The plantar pressure distribution during standing in female patients adjusted to that in healthy adults after THA. Patients with asymmetrical distribution of maximum plantar pressure may benefit from balance assessment and physical therapy.

Transfer of plantar pressure from the medial to the central forefoot in patients with hallux valgus

BackgroundThe aim of the study was to evaluate changes in plantar pressure distribution in feet affected by hallux valgus compared with their contralateral non-affected feet and with the feet of healthy control subjects.MethodsThirty-six patients with unilateral hallux valgus who were indicated for surgery and 30 healthy subjects were assessed on a pedobarographic instrumented treadmill for step length and width, mean stance phase, and plantar foot pressure distribution. Plantar pressure distribution was divided into eight regions.ResultsSignificantly higher plantar pressures were observed in hallux valgus feet under the second and third metatarsal heads (p = .033) and the fourth and fifth toes (p < .001) than in the healthy control feet. Although decreased pressures were measured under the hallux in affected feet (197 [82–467] kPa) in contrast to the contralateral side (221 [89–514] kPa), this difference failed to reach statistical significance (p = .055). The gait parameters step width, step length, and single-limb support did not show any differences between hallux valgus and control feet.ConclusionAlthough the literature on changes in plantar pressures in hallux valgus remains divided, our findings on transferring load from the painful medial to the central and lateral forefoot region are consistent with the development of transfer metatarsalgia in patients with hallux valgus.

Temporal and dynamic changes in plantar pressure distribution, as well as in posture during slow walking in flat and high-heel shoes

The aim of the study was to assess the differences in plantar pressure distribution and in posture during slow and very slow walking on the treadmill in flat and high-heeled shoes. The Pedar-X® (Novel, Munich, Germany) measuring insoles were used to measure the plantar pressure distribution and to assess temporal parameters during walking on the treadmill with the speed v1 = 0.97 ms-1 and v2 = 0.56 ms-1 in flat shoes (FS) and HH. For postural measurement, the SonoSens Monitor Analyzer (Gefremed, Chemnitz, Germany) was used. Thirty healthy females who only occasionally wear HH volunteered to participate in the study (age: 21.8 ± 2.09 years, weight: 55.7 ± 4.05 kg, height: 1.66 ± 0.03 m). For statistical analysis the ANOVA, and paired t-test were used. Significant differences in walking in HH were detected in temporal and plantar pressure variables, compared to FS. The walking speed influenced the temporal variables, but not the measured dynamic parameters, in either shoes. In the sagittal plane, significant differences in all sections of the spine were identified for v1 and v2. While walking in HH, lordosis at lumbar spine decreased significantly as well as at cervical spine, and kyphosis increased in the thoracic spine. In HH statistically significant differences between the walking speeds were observed particularly in the thoracic spine. Walking in high heels caused a plantar pressure changes and curvature of the spine, and the slowing of walking speed did not prevent these changes.

Prolonged occupational standing: the impact of time and footwear

Prolonged occupational standing is strongly related to musculoskeletal disorders. Despite being the main external load bearing interface between the floor and musculoskeletal system, and easy to manipulate, footwear is often ignored as an intervention for standing related disorders. This study aimed to record the effect of prolonged standing on the body and determine the impact of footwear material. Two pairs of surgical clogs were tested, varying only in material hardness. Participants (n = 12) undertook 3 h of standing in each shoe whilst they completed a repetitive series of simulated work tasks. Biomechanical and subjective data were recorded at the start, end and every 30 min during the 3 h of standing. There was an increase in the discomfort of the low back and all lower extremity regions alongside an increase in calf circumference, selected kinematic and kinetic variables, and changes in plantar pressure distribution over the 3 h. Altering the footwear material impacted on low back discomfort and plantar pressures. Shoe preference varied amongst individuals but was consistently associated with an increased medial midfoot contact area. Overall, this study has demonstrated the effect of prolonged standing on the body, has shown footwear impacts both subjective and biomechanical measures and provides information regarding individual differences and footwear preferences.

Effects of orthopedic insoles on static balance of older adults wearing thick socks.

The wearing of socks and insoles may affect the ability of the foot to detect tactile input influencing postural balance. The aim of this study was to investigate whether (1) thick socks adversely affected the elderly postural balance and (2) orthopedic insoles could improve the elderly postural balance while wearing thick socks. Repeated-measures study design. In total, 14 healthy older adults were recruited. A monofilament test was conducted to evaluate foot plantar sensation with and without thick socks. Subjects then performed the Romberg tests under three conditions: (1) barefoot, (2) with socks only, and (3) with both socks and insoles. Postural balance was assessed by measuring the center of pressure movement during standing in each experimental condition. Thick socks significantly decreased the monofilament score ( p < 0.001), suggesting reduction in ability to detect external forces. All center of pressure parameters increased significantly while wearing thick socks ( p < 0.017), implying reduction of postural stability. They then decreased significantly with the additional use of insoles ( p < 0.017). Previous studies have documented the changes in plantar pressure distribution with the use of orthopedic insoles. This study further suggests that such changes in contact mechanics could produce some balance-improving effects, which appears not to have been reported earlier. Clinical relevance Wearing thick socks reduces plantar pressure sensitivity and increases postural sway which may increase risk of falls. Orthopedic insoles and footwear with similar design could potentially be a cost-effective method in maintaining postural balance when wearing thick socks.

Alteração do Ângulo de Pronação da Articulação Subtalar tem Influência na Distribuição de Pressão Plantar: Um Estudo Preliminar

Several studies have investigated the relationship between heel pronation with plantar pressure during gait. With a degree of variability and inluence of the footwear, usually excessive pronation is associated with higher mechanical loads. However, larger loads are commonly associated with pronation. his study aims to compare the plantar pressure distribution among individuals with diferent pronation angles of the subtalar joint angle during gait with controlled speed. he maximum angle of the subtalar joint was determined by capturing images in the frontal plane and the pressure plant peaks were acquired by EMED pressure platform. he pronated group showed pressure plant peaks signiicantly higher in the lateral heel area (18%; p=0.031), medial heel (17%, p=0.034), lateral midfoot (30%; p=0.032) and medial midfoot (41%; p=0.018) when compared to the control group. Excessive pronation of the subtalar joint caused changes in plantar pressure distribution, and an increase in pressure plant peaks, especially in the heel and midfoot regions. his demonstrates the need for a speciic care of this population, mainly because the increased pressure plant peaks is related to pain in the feet and onset of injuries.

Assessment of foot function in patients with pes planus deformity treated with the authors’ own exercise programme – a preliminary report

Abstract Introduction: Foot pain is highly prevalent among persons of all ages. Despite a common belief that it is necessary to perform exercises, there is a scarcity of data regarding their effectiveness. This study sought to assess the effects of a training programme on an improvement in foot function and a reduction in pain. Material and methods: The study group consisted of 15 females with foot pain and flat foot who performed a daily set of 5 exercises for 6 weeks. The Foot Posture Index, a pedobarographic platform postural examination, functional tests (a unipedal stance test with eyes open and closed as well as a bipedal calf raise test) and the Polish translation of the Foot and Ankle Outcome Score (FAOS) were employed to assess the results. These assessment tools were used before and after the intervention. Results: Pedobarographic examinations showed an increase in total support surface as well as a decrease in maximum and average plantar pressures and pressures in particular areas of both feet. The FAOS revealed a reduction in pain and an improvement in the remaining aspects under examination in the majority of participants. No significant differences in the results of functional tests were noted. Conclusions: The exercise programme implemented in the study produces positive outcomes in terms of changes in plantar pressure distribution and leads to a significant reduction in foot pain.

Changes in plantar pressure distribution after long-distance running

Changes in plantar pressure distribution after long-distance running

ОСОБЕННОСТИ РАСПРЕДЕЛЕНИЯ ПОДОШВЕННОГО ДАВЛЕНИЯ ПРИ ПЛОСКО-ВАЛЬГУСНОЙ ДЕФОРМАЦИИ СТОПЫ У ДЕТЕЙ

Pedobarography is a perspective method of feet pathology diagnosis. It evaluates not only static load on the foot, but also functional condition of the feet during movement. Material and methods. Plantar pressure distribution was assessed in 74 healthy children and 98 children with bilateral pes planovalgus. The frontal dynamic index (FDI) was used for evaluation of a valgus deviation of the foot. Results. A statistically significant decrease in the FDI to 50.01 in the younger and to 52.18 in the older age group was observed. Diagnostic efficiency of the FDI was defined. Characteristic changes of plantar pressure distribution in children with pes planovalgus were described.

Effects of Ankle Arthrodesis on Biomechanical Performance of the Entire Foot.

Background/MethodologyAnkle arthrodesis is one popular surgical treatment for ankle arthritis, chronic instability, and degenerative deformity. However, complications such as foot pain, joint arthritis, and bone fracture may cause patients to suffer other problems. Understanding the internal biomechanics of the foot is critical for assessing the effectiveness of ankle arthrodesis and provides a baseline for the surgical plan. This study aimed to understand the biomechanical effects of ankle arthrodesis on the entire foot and ankle using finite element analyses. A three-dimensional finite element model of the foot and ankle, involving 28 bones, 103 ligaments, the plantar fascia, major muscle groups, and encapsulated soft tissue, was developed and validated. The biomechanical performances of a normal foot and a foot with ankle arthrodesis were compared at three gait instants, first-peak, mid-stance, and second-peak.Principal Findings/ConclusionsChanges in plantar pressure distribution, joint contact pressure and forces, von Mises stress on bone and foot deformation were predicted. Compared with those in the normal foot, the peak plantar pressure was increased and the center of pressure moved anteriorly in the foot with ankle arthrodesis. The talonavicular joint and joints of the first to third rays in the hind- and mid-foot bore the majority of the loading and sustained substantially increased loading after ankle arthrodesis. An average contact pressure of 2.14 MPa was predicted at the talonavicular joint after surgery and the maximum variation was shown to be 80% in joints of the first ray. The contact force and pressure of the subtalar joint decreased after surgery, indicating that arthritis at this joint was not necessarily a consequence of ankle arthrodesis but rather a progression of pre-existing degenerative changes. Von Mises stress in the second and third metatarsal bones at the second-peak instant increased to 52 MPa and 34 MPa, respectively, after surgery. These variations can provide indications for outcome assessment of ankle arthrodesis surgery.

Slip-Related Changes in Plantar Pressure Distribution, and Parameters for Early Detection of Slip Events.

ObjectiveTo investigate differences in plantar pressure distribution between a normal gait and unpredictable slip events to predict the initiation of the slipping process.MethodsEleven male participants were enrolled. Subjects walked onto a wooden tile, and two layers of oily vinyl sheet were placed on the expected spot of the 4th step to induce a slip. An insole pressure-measuring system was used to monitor plantar pressure distribution. This system measured plantar pressure in four regions (the toes, metatarsal head, arch, and heel) for three events: the step during normal gait; the recovered step, when the subject recovered from a slip; and the uncorrected, harmful slipped step. Four variables were analyzed: peak pressure (PP), contact time (CT), the pressure-time integral (PTI), and the instant of peak pressure (IPP).ResultsThe plantar pressure pattern in the heel was unique, as compared with other parts of the sole. In the heel, PP, CT, and PTI values were high in slipped and recovered steps compared with normal steps. The IPP differed markedly among the three steps. The IPPs in the heel for the three events were, in descending order (from latest to earliest), slipped, recovered, and normal steps, whereas in the other regions the order was normal, recovered, and slipped steps. Finally, the metatarsal head-to-heel IPP ratios for the normal, recovered, and slipped steps were 6.1±2.9, 3.1±3.0, and 2.2±2.5, respectively.ConclusionA distinctive plantar pressure pattern in the heel might be useful for early detection of a slip event to prevent slip-related injuries.

A cross-sectional study of age-related changes in plantar pressure distribution between 4 and 7 years: A comparison of regional and pixel-level analyses

Quantifying morphological and functional development in children's feet, and thereby establishing development norms is difficult. In addition to practical challenges of experimentation on children, measurement equipment like plantar pressure (PP) platforms are almost exclusively geared towards adult-sized feet. These PP quantification problems may be exacerbated by typical regional data analysis techniques, which further reduce spatial resolution. The goal of this study was to quantify PP distributions in developing children, and also to compare the results obtained from typical (regional) techniques with those obtained from a higher-resolution (pixel-level) technique. Ninety-eight children between four and seven years of age were assessed in a cross-sectional design. Maximum PP distributions were collected for each child, and these pressures were linearly regressed against age. Present results agree with previous investigations in that maximum pressures and maximum pressure changes occurred in the forefoot. However, results from the present pixel-level technique suggest that these changes are limited to the central metatarsals, and that regional methods can suggest significance where none exists in the actual raw (pixel-level) data, due to signal aliasing and, in particular, to conflation of regional boundaries. We postulate that increased central metatarsal pressures are reflective of the coupling between generalised joint laxity decreases and relatively increasingly inclined central metatarsal bones with age.