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At least 19 recordsLinked to original sources

PubMed2005

Cross-sectional geometry of the human forefoot.

The human forefoot presents an interesting biomechanical problem of clinical importance because loads are distributed unequally across multiple bones. The fact that long bones typically have a several-fold safety factor relative to peak loads suggests that metatarsal strengths should be related to their peak loads. This study is the first to systematically examine the cross-sectional geometric properties of the human forefoot and their relationship to external loads during walking and running. We report midlength cross-sectional geometric properties (CA, Ix, Iy, Imax, Imin, J, Zx, and Zy) of metatarsals (1-5) and the hallucial proximal phalanx of a shod industrial population (n = 40) obtained using computed tomography. We then examine the relationship between these measures of shaft strength and published plantar pressure data sets recorded during the following functional activities: standing, at the push-off stage of the walking cycle, the full walking cycle, and running. Cross-sectional geometric properties of the first ray are greater than those of other rays, even when scaled to bone length. This pattern corresponds to the high pressures recorded for the first ray during most activities. The relationships between cross-sectional geometric properties of the lateral metatarsals and peak plantar pressure data are more complex. Metatarsals 2-4 are weakest in most cross-sectional geometric properties. However, metatarsal 2, and to a lesser extent metatarsal 3, experience relatively high peak pressures. On average, geometric measures of axial and bending strengths (adjusted relative to body size) are lower in females than males, and in European Americans than in African Americans, which corresponds to the respective rates of general metatarsal stress fracture in these groups. The discrepancy between strength and plantar pressure values in metatarsals 2 and 3 is consistent with the high incidence of stress fractures in these bones and underscores the importance of soft tissues, such as the plantar fascia and flexor musculature, in moderating metatarsal shaft strain.

Black or African American↗

PubMed2005

A comparison of forefoot stiffness in running and running shoe bending stiffness.

This study characterizes the stiffness of the human forefoot during running. The forefoot stiffness, defined as the ratio of ground reaction moment to angular deflection of the metatarsophalangeal joint, is measured for subjects running barefoot. The joint deflection is obtained from video data, while the ground reaction moment is obtained from force plate and video data. The experiments show that during push-off, the forefoot stiffness rises sharply and then decreases steadily, showing that the forefoot behaves not as a simple spring, but rather as an active mechanism that exhibits a highly time-dependent stiffness. The forefoot stiffness is compared with the bending stiffness of running shoes. For each of four shoes tested, the shoe stiffness is relatively constant and generally much lower than the mean human forefoot stiffness. Since forefoot stiffness and shoe bending stiffness act in parallel (i.e., are additive), the total forefoot stiffness of the shod foot is dominated by that of the human foot.

Adult↗

PubMedDate not supplied

Axial computed tomographic anatomy of the foot: Part III. Forefoot.

Cross-sectional osseous and soft tissue anatomy of the human forefoot as demonstrated by high resolution computed tomography (CT) is described. This report serves an important baseline function because CT may be useful for the evaluation of a variety of forefoot disorders in the clinical setting.

Arteries↗

PubMed2005

Evaluation of the RF field uniformity of a double-tuned 31P/1H birdcage RF coil for spin-echo MRI/MRS of the diabetic foot.

PURPOSE: To evaluate the B1 field uniformity of a double-tuned birdcage coil designed for (31)P/(1)H MRI/MRS spin-echo (SE) imaging of the metatarsal head region of the foot in neuropathic diabetic patients. MATERIALS AND METHODS: A low-pass double-tuned (31)P/(1)H RF birdcage coil was constructed to fit over the adult forefoot. Flip angle (FA) maps were created from B1 data acquired at the 3T (31)P (four normal subjects) and (1)H (five normal subjects) frequencies. T2-weighted (T2-W) (1)H images, (31)P rapid acquisition with relaxation enhancement (RARE) images, and composite SE pulse CSI data were acquired to demonstrate the uniformity of the resulting images and data. RESULTS: The means and standard deviations (SDs) of the range of FAs across the feet of the volunteer subjects indicated good uniformity (the maximum coefficients of variation (CVs) for all of the (31)P and (1)H FA maps were 7.6% and 7.3%, respectively). The FA values across the metatarsal head region indicated a maximum signal intensity variation of +/-3% in a RARE image acquired using an echo train length of 32. CONCLUSION: A (31)P/(1)H birdcage coil constructed for MRI/MRS studies of the human forefoot provided sufficient signal uniformity of SE data to facilitate accurate (31)P concentration measurements in muscle.

Diabetic Foot↗

PubMed1985

The double isotope technique for in vivo determination of the tissue-to-blood partition coefficient for xenon in human subcutaneous adipose tissue--an evaluation.

Local subcutaneous 133xenon (133Xe) elimination was registered in the human forefoot in 34 patients. The tissue/blood partition coefficient for Xe was estimated individually by simultaneous registration of 133Xe and [131I]antipyrine ([131I]AP) washout from the same local depot. When measured in this way, an average partition coefficient for Xe was found to be 4.3 +/- 1.23 ml g-1. This value is significantly lower than the partition coefficient found in a previous in vitro study in which a Xe partition coefficient of 7.5 +/- 1.57 ml g-1 was found. Thus, if the local blood flow is calculated using the partition coefficient found by the double isotope technique, significantly lower values are obtained than if the in vitro determined coefficient is used. This difference is explained mainly by local dilution when injecting xenon subcutaneously. In short-term studies, utilization of the double isotope technique reduces the coefficient of variation on average flow determinations, thus an improvement in accuracy of local blood flow estimation can be obtained compared to the method in which an average partition coefficient is used. For long-term studies a partition coefficient of 7.5 ml g-1 seems valid.

Adipose Tissue↗

PubMed1995

Metabolic and mechanical aspects of foot landing type, forefoot and rearfoot strike, in human running.

The study was undertaken to assess the metabolic and the mechanical aspects of two different foot strike patterns in running, i.e. forefoot and rearfoot striking (FFS and RFS), and to understand whether there is some advantage for a runner to use one or the other of the two landing styles. Eight subjects performed two series of runs (FFS and RFS) on a treadmill at an average speed of 2.50, 2.78, 3.06, 3.33, 3.61, 3.89, 4.17 m s-1. Step frequency, oxygen uptake, mechanical work, and its two components, external and internal, were measured. No differences were found for step frequency, mechanical internal work per unit time and oxygen uptake, while external and total mechanical work per unit time were significantly higher, 7-12%, for FFS. The higher external work was the result of an increase of the work performed against both gravitational and inertial forces. As the energy expenditure was the same it has been speculated that a higher storage and release of energy takes place in the elastic structures of the lower leg with FFS. In a different series of experiments on six subjects contact time, time of deceleration and time of acceleration were measured by means of a video camera while running on the treadmill at 2.50, 3.33 and 4.17 m s-1, both FFS and RFS. Time of deceleration is similar for FFS and RFS, but contact time and time of acceleration are shorter, respectively 12 and 25%, for FFS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1997

Verrucous carcinoma or epithelioma cuniculatum plantare.

Verrucous carcinoma is a rare form of squamous cell carcinoma. It behaves as a slow-growing, locally aggressive and rarely metastasizing tumour. Three clinical cases are presented, with emphasis on clinical presentation, pathological diagnosis and therapeutic approach. The pathogenesis of verrucous carcinoma, including chronic inflammation and human papillomavirus, is also discussed.

Aged↗

PubMed1995

A kinematic comparison of overground and treadmill running.

Treadmills are often used in research projects to simulate overground locomotion, assuming that locomotion is similar on a treadmill and overground. The purpose of this investigation was to determine whether a treadmill could be used to simulate overground locomotion. Twenty-two subjects ran on four different surfaces: overground and three treadmills that differed in size and power. The kinematics of the right leg and foot were studied using two high-speed Locam cameras (lateral and posterior view). The subjects ran in two different shoes at four different speeds (3.0-6.0 m.s-1). The differences in the kinematics between treadmill and overground running could be divided into systematic and subject dependent components. Subjects systematically planted their feet in a flatter position on the treadmill than overground. Most of the lower extremity kinematic variables, however, showed inconsistent trends for individual subjects, depending on the individual subject's running style, running speed, and shoe/treadmill situation. The differences were substantial. It is not yet understood how the human locomotor system adapts to a particular treadmill running situation. However, it is concluded that individual assessment of running kinematics on a treadmill for shoe or shoe orthotic assessment may possibly lead to inadequate conclusions about overground running.

Adaptation, Physiological↗

PubMed2005

Effects of shoe inserts and heel height on foot pressure, impact force, and perceived comfort during walking.

Studying the impact of high-heeled shoes on kinetic changes and perceived discomfort provides a basis to advance the design and minimize the adverse effects on the human musculoskeletal system. Previous studies demonstrated the effects of inserts on kinetics and perceived comfort in flat or running shoes. No study attempted to investigate the effectiveness of inserts in high heel shoes. The purpose of this study was to determine whether increasing heel height and the use of shoe inserts change foot pressure distribution, impact force, and perceived comfort during walking. Ten healthy females volunteered for the study. The heel heights were 1.0cm (flat), 5.1cm (low), and 7.6cm (high). The heel height effects were examined across five shoe-insert conditions of shoe only; heel cup, arch support, metatarsal pad, and total contact insert (TCI). The results indicated that increasing heel height increases impact force (p<0.01), medial forefoot pressure (p<0.01), and perceived discomfort (p<0.01) during walking. A heel cup insert for high-heeled shoes effectively reduced the heel pressure and impact force (p<0.01), an arch support insert reduced the medial forefoot pressure, and both improved footwear comfort (p<0.01). In particular, a TCI reduced heel pressure by 25% and medial forefoot pressure by 24%, attenuate the impact force by 33.2%, and offered higher perceived comfort when compared to the non-insert condition.

Adult↗

PubMed1999

[Are antiphospholipid antibodies thrombogenic in the course of human immunodeficiency virus infection?].

Lupus-like anticoagulant is commonly encountered in human immunodeficiency virus infection although thromboembolic manifestations are rare in HIV patients. We report the case of an HIV patient who developed gangrene of both forefeet associated with anticardiolipin antibodies. A 42-year-old woman had a 12-year history of HIV infection (stage B2). She presented with painful gangrene involving the forefeet of 4-day duration. Doppler ultrasonography, electromyography and nailfold capillaroscopy were normal. Skin biopsy revealed intracapillary thrombi and severe necrosis within the hypodermis; there was no evidence of vasculitis. Laboratory findings showed a marked inflammatory syndrome and the presence of anticardiolipin antibodies (IgG: 22 GPL U/ml). Several cutaneous manifestations are known to be associated with antiphospholipid syndrome, such as livedo reticularis, ulcers and gangrene of the extremities. Skin biopsy often shows noninflammatory thrombosis of small vessels within the dermis. Microcirculation damages have also been described in HIV infection, mainly vasculitis. In the present case report, the absence of both vasculitis and other causes suggest that anticardiolipin could be the culprit. But, it is possible that painful gangrene of the forefeet was secondary to HIV infection.

Adult↗

PubMed2006

Intramuscular nerve distribution pattern of the oblique and transverse heads of the adductor hallucis muscles in the human foot.

To understand which layer of the intrinsic muscles of the foot the adductor hallucis muscle belongs to, it is essential to investigate the innervation patterns of this muscle. In the present study, we examined the innervation patterns of the adductor hallucis muscles in 17 feet of 15 Japanese cadavers. We investigated the intramuscular nerve supplies of the adductor hallucis muscles in six feet and performed nerve fiber analysis in three feet. The results indicate that: (i) the oblique head of the adductor hallucis muscle is divided into three compartments (i.e. lateral, dorsal and medial parts) or two compartments (i.e. dorsal and medial parts) based on its intramuscular nerve supplies, but we could not classify the transverse head into any parts; (ii) the communicating twig between the lateral and medial plantar nerves penetrated the oblique head of the adductor hallucis muscle in 13 of 17 feet (76.5%); (iii) the penetrating twig entered between the lateral and dorsal parts of the oblique head, passed between the lateral and medial parts of this muscle and then connected with the medial plantar nerve; and (iv) the majority of the nerve fibers of the penetrating twig derived from the lateral plantar nerve. The present study demonstrated that only the lateral part of the oblique head of the adductor hallucis muscle had a unique innervating pattern different from other parts of this muscle, suggesting that the lateral part of the oblique head has a different origin from other parts of this muscle.

Aged↗

PubMed2001

The adductor hallucis revisited.

To evaluate anatomic variability in the insertion of the adductor hallucis into the lateral sesamoid and proximal phalanx of the great toe and to evaluate the extent of release of the adductor hallucis tendon performed through an incision in the dorsal first-web space, we recorded the angle of hallux valgus in 42 fresh-frozen specimens from human cadavers. An incision was made for a realignment of the soft tissues, dissecting down to the level of the intermetatarsal ligament. A loop of suture was placed around the identifiable adductor hallucis tendon through this incision along the lateral aspect of the lateral sesamoid. Then a plantar dissection removed all soft tissue to the level of the intermetatarsal ligament, adductor hallucis (transverse and oblique heads), lateral sesamoid, and lateral flexor hallucis brevis. The Insertion of these muscles into the proximal phalanx was evaluated. Specifically, we looked for separate slips of the adductor tendon inserting into the base of the proximal phalanx or separate insertions of the adductor tendon and the tendon of the flexor hallucis brevis muscle. In 33 of the 42 specimens, the entire adductor hallucis tendon had been isolated by the loop of suture through the incision in the dorsal first web. In eight of the remaining nine specimens, a small slip of the tendon (comprising less than 25% of its substance) had not been included. No specimen was found to have a separate slip of the adductor tendon inserting into the base of the proximal phalanx. Instead, all specimens were found to have only a conjoined insertion of fibers of the adductor hallucis and of the flexor hallucis brevis from the lateral sesamoid into the base of the proximal phalanx. We did not identify a separate tendon-insertion into the proximal phalanx in any specimen. Therefore, great caution should be exercised in releasing an isolated insertion of the adductor tendon from the base of the proximal phalanx of the great toe since it may actually represent the conjoined insertion of the lateral flexor hallucis brevis tendon and the adductor tendon. We found that by simply releasing the adductor tendon from its insertion along the lateral aspect of the sesamoid, accomplished through an incision in the dorsal first web, that an adequate release was achieved in most specimens.

Cadaver↗

PubMed2004

Ectodermal dysplasia with tetramelic deficiencies and no mutation in p63: odontotrichomelic syndrome or a new entity?

The ectodermal dysplasias (ED) are a large and complex group of diseases characterized by anomalies of the ectoderm and its derivates, often associated with malformations in other organs. We report a patient with an ectodermal dysplasia affecting hair, teeth, and nails and malformations of all four extremities including absence of several rays in the hands and feet. This patient shares many similarities with odontotrichomelic syndrome, a rare ectodermal dysplasia syndrome that has so far only been described in three individuals. However, some differences exist and this patient might also represent a separate ectodermal dysplasia syndrome. p63, a gene that is mutated in a number of syndromes associated with ectodermal dysplasia and limb malformations, was considered a possible candidate gene. However, no mutation in p63 was identified.

Adult↗

PubMed2004

Diagnostic value of magnetic resonance imaging of the forefeet in early rheumatoid arthritis when findings on imaging of the metacarpophalangeal joints of the hands remain normal.

OBJECTIVE: To investigate the diagnostic role of magnetic resonance imaging (MRI) of the forefeet in patients with early rheumatoid arthritis (RA) in whom findings on MR images of the hands are normal and conventional radiographs of the hands and feet do not show erosions. METHODS: The study group comprised 25 patients with early RA (disease duration of <12 months) in whom erosions were not demonstrated on conventional radiographs of the hands and feet. These patients underwent MRI of the clinically dominant hand to detect signs of arthritis. If results of MRI of the hand were normal according to the Outcome Measures in Rheumatology Clinical Trials (OMERACT) RA-MRI scoring system (RAMRIS), MRI of the dominant forefoot was performed. The MRI protocol comprised coronal and sagittal T1-weighted spin-echo (before and after administration of contrast medium), coronal fat-suppressed short tau inversion recovery sequences, coronal and sagittal T2-weighted turbo spin-echo sequences, and axial fat-suppressed T1-weighted spin-echo sequences after administration of contrast medium. MRI of the forefeet was analyzed on the basis of a modified RAMRIS. RESULTS: MRI revealed pathologic findings in the hands of 15 of 25 patients (edema in 9 patients, synovitis in 12, erosions in 6, defects in 3). In 10 patients with a mean disease duration of 9.4 weeks, hand MRI scans were normal according to RAMRIS. Four of these 10 patients had tenosynovitis of the finger flexor tendons (there was no OMERACT criterion for tenosynovitis). RAMRIS analysis of the corresponding MRI scans of the forefeet of these patients revealed signs of edema in 7 patients, synovitis in all 10 patients (at the third metatarsophalangeal [MTP] joint in 7, at the fourth MTP joint in 6, at the first MTP joint in 4, and at the fifth MTP joint in 2 patients), tenosynovitis of the foot flexor tendons in 2 patients, erosions at the second and third MTP joints in 1 patient, and a single defect at the first MTP joint in 1 patient. CONCLUSION: RAMRIS analysis of MRI scans of the forefeet detected synovitis and bone edema in patients with early RA in whom MRI of the finger joints was normal. MRI of the forefeet contributes an additional tool aimed at earlier and more accurate diagnosis and thus might allow an earlier decision to start appropriate medication in patients with early RA.

Adult↗

PubMed2002

MR imaging of the forefoot under weight-bearing conditions: position-related changes of the neurovascular bundles and the metatarsal heads in asymptomatic volunteers.

PURPOSE: To assess practicability of weight-bearing magnetic resonance (MR) imaging of the forefoot, and to demonstrate position-related changes of the neurovascular bundles and the metatarsal heads in asymptomatic volunteers. MATERIALS AND METHODS: With an open-configuration MR system, 32 feet of 32 asymptomatic individuals aged 20-60 years were studied in supine and weight-bearing body positions. Transverse T1-weighted spin-echo MR images were performed. MR images were evaluated qualitatively with regard to image quality, visibility, and position-dependent changes of the neurovascular bundle. In addition, the position of the metatarsal heads was analyzed quantitatively. RESULTS: Weight-bearing MR imaging was feasible in all 32 feet. Quality of MR images obtained in the weight-bearing position was superior to that obtained in the supine position (P < 0.05). A change in the position of the neurovascular bundle from below a virtual line paralleling the plantar cortical line to above this line was present in 50 of 61 instances (82%) between the supine and the weight-bearing positions. When changing from the supine to the weight-bearing position, there was a significant decrease in the distance between the plantar skin and the metatarsal heads for the second (mean 4.5 mm), third (mean 4.4 mm), and fourth metatarsal heads (mean 3.7 mm) (P < 0.0001). However, the difference for the first (mean 0.5 mm) and fifth (mean 0.9 mm) metatarsal heads was not significant. CONCLUSION: Weight-bearing MR imaging of the forefoot is feasible using an open-configuration MR system and demonstrates position-related changes of the neurovascular bundles relative to the metatarsal heads, as well as position-related changes of the metatarsal heads themselves.

Adult↗

PubMed2007

Kinematic changes of the foot and ankle in patients with systemic rheumatoid arthritis and forefoot deformity.

Minimal published data exist characterizing the effect of rheumatoid arthritis of the forefoot (RA) on multi-segmental gait kinematics. The purpose of this study was to examine specific changes in segmental foot motion in patients with RA as compared to persons without foot/ankle pathology. This was a cross-sectional, descriptive study consisting of 22 preoperative adult patients (29 feet) diagnosed with RA and 25 adult patients with no known foot pathology (Control). All RA patients were evaluated by the same orthopaedic surgeon. This group consisted of 20 women and 2 men with a mean age of 54 years (range, 17-76 years). The Control cohort consisted of 13 men and 12 women with a mean age of 41 years (range, 27-73 years). Foot and ankle motion data for the RA population were obtained using a 15-camera Vicon Motion Analysis System (Vicon Motion Systems, Inc., Lake Forest, CA). Anterior-posterior, lateral, and modified coronal radiographic views were obtained to relate marker position to underlying bony anatomy. Temporal and three-dimensional kinematic parameters were obtained via the 4-segment Milwaukee Foot Model. Quantitative comparisons of range of motion values during the seven phases of gait were made between RA and Control ankles using unpaired nonparametric methods. The RA group showed significant differences (p < 0.001) as compared to Controls with prolonged stance time, shortened stride length, increased cadence, and a walking speed that was 80% of Control. Overall, kinematic data in the RA cohort showed significant differences (p < 0.001) in motion for tibial, hindfoot, and forefoot motion as compared to Controls. The effect of RA on segmental foot motion is poorly understood. This study characterized the effect that RA has on motion about the foot and ankle during gait, providing insight into this pathology to improve quantitative assessment, treatment planning, and rehabilitative care.

Adult↗

PubMed1997

Solving the problem of contractures--throw out the recipe book?

Explore the source record for details and available documents.

Ankle Joint↗

PubMed1997

A weight bearing method for determining forefoot posting for orthotic fabrication.

Orthotic prescription for forefoot posting is commonly based upon measures of the forefoot performed on a non-weightbearing foot. However, the relationship of measures of the unloaded foot to determine orthotic prescription for compensatory forefoot function during gait is still in question. Another approach to determine orthotic prescription is to measure the height of forefoot posting necessary to prevent excessive pronation of the subtalar joint during weightbearing. Therefore, the purpose of this study was to determine the intrarater, interrater and day-to-day reliability of forefoot measures during an active, weightbearing movement. Thirty-two volunteers, 18 females (mean age 38.9 +/- 15.3 yr) and 18 males (mean age 44.8 +/- 20.6 yr) participated in the study. Four examiners performed repeated forefoot measures on both feet using the weightbearing technique during two test sessions separated by a week. Intrarater and interrater reliability (ICC (3,1)) ranged from 0.90 to 0.95 and 0.87 to 0.94, respectively. Day-to-day reliability (ICC (1,1)) ranged from 0.84 to 0.88 for all measures. We conclude that the weightbearing method used in this study to determine forefoot posting is reliable. The acceptable reliability of this method justifies the need for future investigations of the validity and the clinical efficacy of this technique for orthotic prescription.

Adult↗