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Abstract We are surrounded by soft materials in a variety of physical and chemical states, which can be easily deformed under external stimuli. Thumbnails Document Outline Attachments. Highlight all Match case. Whole words. Toggle Sidebar. Zoom Out. More Information Less Information. Enter the password to open this PDF file:.

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Mechanical Instability

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The evaluators responsible for the technical examinations were trained by the first author to compare the efficiency of these examinations with that of the physical examinations, with regard to determining the presence of mechanical joint instability. This evaluation was done by means of two different measurements, using digital imaging software, with an interval of two weeks between the measurements.

The radiograph evaluators were two doctors who were unaware of the treatment method that had been used.

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This evaluation in double-blind format on the results from the stress radiographs made it possible to validate the inter and intra-observer variability of the angle measurements on digital radiographs produced with ankle stress, as well as ruling out the possibility that knowledge of the treatment method might influence the results from the measurements. In evaluating the baseline data on the patients included in this study, we noted that the distribution was homogenous, as shown in Table 1.

This situation of similarity between the treatment groups showed the efficiency of the randomization process. The trauma mechanisms associated with the injury are listed in Table 2. Table 3 shows the evaluation made one week after the injury. At this phase of the evaluation, we noted that there was only a difference between the two forms of treatment in relation to the comfortableness while walking and the AOFAS score, such that greater numbers of patients in the group treated with a sports air cast orthosis felt comfortable while walking, and this group also had higher AOFAS scores.

The ligaments affected were as shown in Table 4. At the next evaluation, three weeks after the treatment started, all the patients in this study presented stability in the physical examination, which was demonstrated by disappearance of the anterior drawer signal, except in patient 69, who continued to present a clinically unstable ankle. Table 5 shows our results at this point in the evaluation. Here, we observed greater mean pain although the difference was insufficient to configure a clinical variation and AOFAS score in the group treated with a long orthosis.

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The number of days off work was significantly different such that it was greater in the group treated with the long orthosis. The results from the evaluation after six weeks are shown in Table 6. At this point, when orthosis use was discontinued, we observed greater AOFAS scores in the group treated with a functional orthosis, without any difference in relation to pain, limitation on activities of daily living or joint mobility.

The AOFAS score was significantly different only in the evaluation in the first week, according to the number of ligaments injured, and it was worse when three ligaments were injured, in comparison with one or two. These results are in Table 7. Twelve weeks after the trauma, we were no longer able to see any differences between the two groups, as shown in Table 8.

The clinical evaluation on joint stability by means of the anterior drawer test did not show any difference between the groups, with the exception of one case that evolved with joint instability, in the group initially treated with a long orthosis. There was no difference in the values for the angles measured on the radiographs with stress, between the two groups. The commonest trauma mechanism for ankle ligament injuries consists of twisting the ankle with inversion, plantar flexion and internal rotation.

The lateral ligaments are the structures most frequently injured in trauma involving twisting of the ankle, particularly the anterior talofibular and calcaneofibular ligaments. Injury to the deep deltoid ligament is related to abnormal variation of the talus inside the malleolar pincer, with consequent impact between the talus and the internal face of the medial malleolus, leading to contusion of the ligament at this locality. Through evaluating the patient distribution in this study between the treatment groups, we observed small variations in the capacity for weight-bearing soon after the trauma, which were more frequent among the patients treated with the functional orthosis initially, and in the intensity of pain evaluated according to the visual analogue scale.

We consider that this variation was of little importance, since the difference observed between the groups was less than 2 0. This confirms the need for adequate standardization of approaches, based on the effectiveness, cost and safety of the treatment. We classified the acute ligament injuries in accordance with Chart 1 West Point grading system for ankle ligament injuries , since we agree that what differentiates the injuries is basically the presence of joint instability as a consequence of the injury, which occurs in cases of complete injuries, even if only one ligament is affected anterior talofibular.

Proper history-taking and detailed physical examination are the keys to adequate diagnosing of severe acute ankle ligament injuries. In our opinion, based on observation of the sample of this study, an initial clinical evaluation performed delicately enables identification of joint instability through a positive anterior drawer test. One hand is then placed on the distal tibia and palm of the other hand on the calcaneus.

Pressure is then applied in opposing directions. The anterior displacement of the talus can be viewed, felt and palpated by the examiner. Presence of pain, a perception of subluxation and the suction sign depression of the skin on the anterolateral face of the ankle at the time of the test are described as positive findings. The evaluation one week after the trauma showed that the AOFAS score was greater among the patients treated with the functional orthosis, thus indicating that the patients were better off with the functional immobilization.

This had been expected, but the greater comfortableness when walking and the fact that there was no difference in reported pain were contrary to our initial expectation that the orthosis that provided greater stability would also provide greater comfort for patients during the initial stages of the clinical treatment. In the evaluation conducted three weeks after the trauma, we observed that there was greater mean pain although the difference was insufficient to configure clinical variation and higher AOFAS scores among the patients in the group immobilized with the long orthosis.

At this evaluation, all of the patients except number 69 who evolved with chronic joint instability had already ceased to present clinical signs of joint instability. The number of days off work was significantly greater in this group. After six weeks of treatment, when the orthosis was removed for activities of daily living, and when the patient returned to physical activities with protection using the functional orthosis , only the AOFAS scoring was different between the groups, such that it was higher among the individuals immobilized with a functional orthosis.

At the three-month evaluation, there was no longer any difference between the groups Table 8. At this point, the stability was evaluated by means of radiographs using manual stress. The x-ray with varus stress on the ankle was done using the anteroposterior or pincer position while forced inversion was performed on the ankle in a position of slight plantar flexion.

The angle between the tibial pilon and the proximal portion of the talar dome was measured Fig. The anterior drawer test was performed by means of a lateral radiograph on the ankle while attempts were made to perform anterior translation of the talus in the malleolar pincer. We did not observe any difference between the radiographic findings under stress and the physical examination. Magnetic resonance reliably confirms the presence of lateral ligament injury and helps in identifying injuries associated with ankle ligament injuries, particularly the presence of fibular and posterior tibial tendon injuries, osteochondral lesions of the talus and contusional edema of the talus, among others.

We used this examination to rule out the presence of associated injuries that might necessitate specific treatments.

This was the situation of 15 patients who were initially enrolled for the study presented here. Three weeks after the injury, the phase of scar tissue maturation begins. At this time, the collagen fibers mature and become fibrous scar tissue.


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After six to eight weeks, the new collagen fibers already tolerate normal demands. However, the remodeling process on ligament injuries lasts for 6 to 12 months. A survey of Brazilian orthopedists 1 showed that severe acute ankle ligament injuries severe acute ankle ligament injuries were treated conservatively, with rigid immobilization, by We have noticed that there is no homogeneity in diagnosing or treating severe ankle ligament injuries and, moreover, that there is uncertainty regarding the real incidence of residual instability of the ankle joint, since this situation is not differentiated from other forms of unsatisfactory results after this injury.

The most recent meta-analysis, which included 16 randomized or quasi-randomized studies that compared the results from conservative and surgical treatment for ankle ligament injuries, 20 concluded that there was insufficient evidence regarding the best form of treatment for these injuries. The recommendation was that the complications and high cost relating to the surgical procedure should be taken into consideration. The best option for most patients is conservative treatment with careful follow-up, in order to identify individuals who continue to show symptoms.

Another meta-analysis 21 allowed the conclusion that functional treatment has more favorable results, with a higher percentage of patients who return to sports, shorter time taken to return to work, lower levels of residual edema, smaller limitations on mobility, less sensation of instability and greater satisfaction. The intension in the present study was to use orthoses that are easily found on the market, so that it becomes possible to adequately reproduce this study and facilitate future papers involving larger numbers of patients, in multicenter studies.

Our study showed that both of the proposed methods produced very good results regarding mechanical stabilization of ankle ligament injuries that were treated conservatively. The differences observed related to greater pain in the three-week evaluation in the group with the long orthosis and, also in this group, greater functional incapacity AOFAS score in the evaluations after one, three and six weeks.


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After three months, there were no differences between the groups. Several authors have agreed that conservative treatment is ideal.

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In cases of residual mechanical instability, a secondary ligament reconstruction procedure can be implemented, even if years have elapsed since the injury, with excellent results. Occurrences of repeated spraining and persistent symptoms pain during physical activity, recurrent edema, weakness and feelings of instability have been considered to represent chronic instability of the ankle.

The mechanical factors included pathological laxity understood to be greater mobility in relation to normal and on the normal contralateral side, caused by failure of the ligament structures , alteration of the kinematics of the elbow and degenerative synovial alterations. The functional factors include altered proprioception, altered neuromuscular control, strength deficits and deficient postural control. We consider that the presence of functional instability feelings of instability without mechanical instability of the joint is responsible for recurrence of the injury and for the consequent poor results observed by several authors.

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This situation can be prevented and treated by means of an appropriate rehabilitation program, with the aim of restoring muscle strength, normal gait, balance and proprioception. Conservative treatment of severe acute ankle ligament injuries leads to mechanical stability of this joint in a large proportion of the cases. There was no difference in the joint stability results, comparing between the two conservative treatment groups. The patients who underwent initial treatment using a functional orthosis sports air cast presented less pain and better functional results than seen in the group initially immobilized using a long orthosis robot boot.

The clinical examination was equivalent to the x-ray examination with regard to manual stress in evaluating ankle joint stability. Como o ortopedista brasileiro trata entorse lateral agudo do tornozelo? Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation. Foot characteristics in association with inversion ankle injury. J Athl Train.