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[en] Humans can run within a wide range of speeds without thinking about stabilizing strategies. The leg properties seem to be adjusted automatically without need for sensory feedback. In this work, the dynamics of human running are represented by the planar spring mass model. Within this framework, for higher speeds, running patterns can be stable without control strategies. Here, potential strategies that provide stability over a broader range of running patterns are considered and these theoretical predictions are compared to human running data. Periodic running solutions are identified and analyzed with respect to their stability. The control strategies are assumed as linear adaptations of the leg parameters-leg angle, leg stiffness and leg length-during the swing phase. To evaluate the applied control strategies regarding their influence on landing behavior, two parameters are introduced: the velocity of the foot relative to the ground (ground speed matching) and the foot's angle of approach. The results show that periodic running solutions can be stabilized and that control strategies, which guarantee running stability, are redundant. For any swing leg kinematics (adaptation of the leg angle and the leg length), running stability can be achieved by adapting the leg stiffness in anticipation of the ground contact.
[en] The anatomy of the foot, with its overlapping bones, lends itself very well to examination by computerized tomography (CT). A brief summary of the basic principles of CT is presented. Tissues of different structures within the body have different elemental compositions resulting in different x-ray attenuation qualities. The linear attenuation coefficient μ is a property that is dependent on the atomic number and density of the materials x-rayed and on the energy spectrum of the x-ray beam. With routine radiography, the total attenuation value of the x-ray beam is presented. With CT, the computer unscrambles the attenuation information of the x-ray beam and presents the average attenuation of each small volume element that makes up the body slice
[en] Purpose: To determine whether percutaneous transluminal angioplasty (PTA) and enclosed thrombolysis (ET) is superior to PTA alone in the treatment of femoropopliteal occlusions.Methods: Twenty-five patients with 5-15-cm-long occlusions in the femoropopliteal segments, with otherwise normal run-in arteries and at least one normal tibioperoneal artery to the foot, were randomized to ET/PTA or PTA alone. Ankle brachial systolic index (ABI) was measured before the procedure and at 24 hr and 12 months after the procedure, when a duplex scan was also carried out. End points in the study were patency at, or repeat intervention before, 12 months.Results: Procedures were successful in 23 of 25 patients. There was one immediate occlusion of tibioperoneal arteries, and one early reocclusion of a reopened segment in the ET/PTA group. There was one early reocclusion in the PTA group. At 12 months patency was 70% and 69.2% in the ET/PTA and PTA groups respectively. Covariant analysis showed no significant difference in ABI between the two groups at any of the three measurement times.Conclusion: This trial demonstrated no difference between ET/PTA and PTA alone in femoropopliteal occlusions associated with normal proximal arteries and at least one normal tibioperoneal artery.
[en] A radiological study on sesamoid bones of hands and feet was done in Korea adults who visited the Capital Armed Forces General Hospital Of Korea during last 10 months from Jan. 1, to Oct, 30, 1970. The incidence of presence or absence of sesamoid bones in each possible site and shape and partition were studied in 250 males and 200 females. The results are follow: 1. In hands, two sesamoids are present at metacarpophalangel joint of thumb in all and one at metacarpophalangeal joint of little finger in half, metacarpophalangeal joint of index, interphalangeal joint of thumb. Metacarpophalangeal joint of ring finger were other sites, in order of frequency. 2. In feet, two sesamoid are present at metacarpophalangeal joint of great toe in all, but the incidence at other sites are much lower comparison to hands and the sites are interphalangeal joint of great toe, metacarpophalangeal joint of 5th toe, metacarpophalangeal joint of 2nd toe, and metacarpophalangeal joint of 4th toe in order frequency. 3. In comparison with sexes, the incidence is a little greater in female at every site. 4. In general, the partition line of sesamoid bone is transverse, and fracture line of sesamoid is longitudinal. 5. In comparison with Europeans, the incidence of sesamoid bone at interphalangeal joint of thumb and great toe is about half, and at other sites, except metacaso phalangeal joint of thumb abd great toe, the incidence was smaller in each site.
[en] Considering the increasing demand for CT examinations of the foot, especially in the case of tarsal injuries, a technique and the appearance of the various anatomical elements of the normal foot on CT scans, are described
[fr]Devant la demande croissante d'exploration du pied en tomodensitometrie, notamment dans le cadre des traumatismes du tarse, on expose une technique et les aspects des differents elements anatomiques du pied normal sur des coupes tomodensitometriques
[en] Objective: Wearable gait event detection (GED) techniques have great potential for clinical applications by aiding the rehabilitation of individuals in their daily living environment. Unlike previous wearable GED techniques, which have been proposed for offline detection or laboratory settings, we aimed to develop a real-time GED system adapted for utilization in the daily living environment. Approach: This study presents a novel GED system in which foot clearance and sagittal angular velocity were incorporated to realize real-time GED in a real-world environment. The accuracy and robustness of the proposed system were validated in a real-world scenario that consisted of complex ground surfaces, i.e. varying inclinations. Forty-three subjects (23–83 years) were included in this study, and a total of 8866 gait cycles were recorded for analysis. Main results: The proposed system demonstrated consistently high performance in detecting toe off (TO) and heel strike (HS) events in indoor and outdoor walking data which was supported by high performance scores. The detection accuracy of the walking data reached 2.59 ± 13.26 ms (indoor) and 3.31 ± 14.78 ms (outdoor) for TO events, 3.36 ± 15.92 ms (indoor) and 3.77 ± 16.99 ms (outdoor) for HS events. The proposed system showed better performance in detection precision than state-of-the-art real-time GED methods. Significance: The proposed system will benefit the development of long-term analysis and intervention techniques for use in clinics and daily living environments. (paper)
[en] Of 462 Finnhorses (age 1-20 years) evaluated and graded (scale 0-5) radiographically for ossification of the collateral cartilages of the 3rd phalanx of the front feet, 22.9% were totally free from sidebones (Grade 0), and 49.1% had minimal or mild ossification (Grade 1 or 2) at the base of 1 or more of the cartilages. Moderate ossification (Grade 3) was present in 10.2% of the horses, whereas ossification was advanced (Grade 4) or extensive (Grade 5) in 17.8%. In most horses > 1 cartilage was affected and 7.6% of the horses had separate centres of ossification in 1 or more of the cartilages. Large sidebones and separate centres of ossification were more common in females than in males (P < 0.001). The incidence of large sidebones was lower in young females (1-3 years) than in mares 4-6 years of age (P < 0.05), but did not increase significantly with age when young horses, 4-6 years of age, were compared with older ones. Grade 4 and 5 sidebones as well as separate centres of ossification were more common in the lateral than in the medial cartilage (P < 0.001), but no difference was observed in this respect between the front feet
[en] The absence of soft tissue superimposition on bone makes CT greatly superior to conventional radiographs, even using special views, for demonstrating the hind foot. Views derived from both methods are compared. Semi-coronary and transverse planes have been defined in relation to specific points in the tarsus. In the semi-coronary plane, the calcaneus-valgus angle varies from +100 (valgus) to -10deg (varus) and the sustentaculum angle varies from 18 to 28deg. In the transverse plane, the plantar talo-calcaneal angle is 60deg to 70deg and the calcaneal-cuboidal angle is 20deg to 35deg. These values are based on measurements of 62 normal feet. They are valuable for judging quantitatively post-traumatic deformities, displacement of fragments and operative results. (orig.)
[de]Die ueberlagerungsfreie Abbildung der Knochen und Weichteile des Rueckfusses mittels der Computertomographie ist der konventionellen Radiologie mit Uebersichtsaufnahmen und Spezialeinstellungen weit ueberlegen. Schichten beider Methoden werden vergleichend dargestellt. Die Ebene fuer semikoronare und transversale Schichten wird an markanten Fusswurzelpunkten festgelegt. In der semikoronaren Ebene wird der Calkaneus-valgus-Winkel mit +10 Grad (valgus) bis -10 Grad (varus) und der Sustentaculum-Winkel mit 18-28 Grad gemessen. In der transversalen Ebene ist der plantare talokalkaneare Winkel (60-70 Grad) und der kalkaneo-kuboidale Winkel (20-35 Grad) bestimmbar. Die an 62 klinisch und subjektiv gesunden Fuessen ermittelten Werte dienen als Bezug fuer die Beurteilung und quantitative Erfassung von posttraumatischen Deformierungen und Fragmentverlagerungen sowie zur Beurteilung nach operativer Reposition. (orig.)
[en] This paper reports on symptomatic Achilles tendon abnormalities (rupture, tendinitis) evaluated with MR imaging during the healing phase after either surgical or conservative treatment. A total of 21 patients were studied. Fifteen of 21 underwent surgery (13 tendon ruptures) and six were managed conservatively (one rupture). MR studies were obtained before treatment in 11, at 3 months in eight, at 6 months in seven, and at 12 months in 12. The 1.5-T spin-echo and gradient-echo images were correlated with clinical results, planter reflex response times, and calf force measurements. Sequential T2 times were obtained from representative levels in the tendons