The influence of pain obesity and quadriceps strength on the gait of osteoarthritis patients

info:eu-repo/semantics/publishedVersio

The influence of age, strength and stiffness on proprioception in knee osteoarthritis

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Six-minute walk test and timed up and go test in persons with transfemoral amputations.

2011– Abstract publication “Reliability of the Six Minute Walk Test and Timed Up & Go Test in Persons with Transfemoral Amputation”, Physiotherapy, 97, Supplement 1, June 2011, p: S18-S1415 - Special Interest Report Abstracts, pages. S227. (IF=0.641)Purpose: The purpose of this study was to analyze the between two days test-retest reliability of the Six-Minute Walk Test (6MWT) in persons with Transfemoral (TF) amputation. Additionally, relationship between the distance of walking in the 6MWT and the time to perform the Timed Up & Go Test (TUGT) was investigated. Relevance: Transfemoral amputation results in permanent disability and impairment among people of all ages. Therefore, the main goals of rehabilitation programs are the improvement of functioning, especially mobility, and successful reintegration in the community. Generally, the effectiveness of these programs is assessed in terms of ability to walk independently, as well as, the maximum functional independence achieve by the subject. In several pathologies and age groups, the 6MWT and the TUGT are considered as gold standard measures showing high test-retest reliability. Additionally, good results were found in subjects with transtibial amputation. Thus, it becomes relevant to explore the reliability of these two tests in other lower-limb amputees, such as TF one's. Participants: Thirty subjects (25 men; 5 women) with unilateral TF amputation, mean(SD) age 44(17.3)yr, height 169.9(7.6)cm, body mass 71.7(15.2)kg, body mass index 24.7(5.3)kg/m2 participated in this study. They were recruited from hospitals, rehabilitation centers and prosthetic manufactures of Lisbon. All participants gave their written informed consent. Methods: Participants performed one trial of 6MWT and two trials of TUGT on two different days, in a test-retest study design. After being instructed to walk along a 30-m indoor corridor, the subjects performed the 6MWT. In order to minimize the influence of fatigue, the TUGT was carried out half an hour later. Each subject performed twice this test with a two minutes rest time between trials. On the second day, the tests were performed in the same order and time. Analysis: Descriptive statistics are reported as mean±SD. Before comparisons, data were tested for normality with the Shapiro Wilk test. Since distributions were skewed, comparisons were computed using Wilcoxon signed-rank test. Reliability of the two trials was examined with Intraclass Correlation Coefficient (ICC3). Spearman´s rank correlation coefficient was used to evaluate statistical dependence between 6MWT and TUGT. Statistical significance was set at p<0.05. Results: Between days comparisons of the 6MWT (day1, 314.0±109.7m; day2, 329.4±109.7m; p<0.001) and the TUGT (day1, 13.3±4.7s; day2, 12.7±4.5s; p<0.001) showed better values in second day. ICC3 were 0.97 and 0.96 for 6MWT and TUGT, respectively. High correlations were observed between 6MWT and TUGT (day1, rS =-0.91, p<0.001; day2, rS =-0.90, p<0.001). Conclusions: The results showed high test-retest reliability between days, both for the 6MWT and the TUGT. Subjects that walked longer distance in 6MWT performed the TUGT in less time. Implications: The 6MWT might be considered as a reliable instrument to measure functional capacity in persons with TF amputation. The TUGT should be used for assessment of physical mobility, postural control, set of transfers, level walking, and turns in amputees

An Informational Algorithm as the Basis for Perception-Action Control of the Instantaneous Axes of the Knee

Traditional locomotion studies emphasize an optimization of the desired movement trajectories while ignoring sensory feedback. We propose an information based theory that locomotion is neither triggered nor commanded but controlled. The basis for this control is the information derived from perceiving oneself in the world. Control therefore lies in the human-environment system. In order to test this hypothesis, we derived a mathematical foundation characterizing the energy that is required to perform a rotational twist, with small amplitude, of the instantaneous axes of the knee (IAK). We have found that the joint’s perception of the ground reaction force may be replaced by the co-perception of muscle activation with appropriate intensities. This approach generated an accurate comparison with known joint forces and appears appropriate in so far as predicting the effect on the knee when it is free to twist about the IAK

Pigmentation plasticity enhances crypsis in larval newts: Associated metabolic cost and background choice behaviour

In heterogeneous environments, the capacity for colour change can be a valuable adaptation enhancing crypsis against predators. Alternatively, organisms might achieve concealment by evolving preferences for backgrounds that match their visual traits, thus avoiding the costs of plasticity. Here we examined the degree of plasticity in pigmentation of newt larvae (Lissotriton boscai) in relation to predation risk. Furthermore, we tested for associated metabolic costs and pigmentation-dependent background choice behaviour. Newt larvae expressed substantial changes in pigmentation so that light, high-reflecting environment induced depigmentation whereas dark, low-reflecting environment induced pigmentation in just three days of exposure. Induced pigmentation was completely reversible upon switching microhabitats. Predator cues, however, did not enhance cryptic phenotypes, suggesting that environmental albedo induces changes in pigmentation improving concealment regardless of the perceived predation risk. Metabolic rate was higher in heavily pigmented individuals from dark environments, indicating a high energetic requirement of pigmentation that could impose a constraint to larval camouflage in dim habitats. Finally, we found partial evidence for larvae selecting backgrounds matching their induced phenotypes. However, in the presence of predator cues, larvae increased the time spent in light environments, which may reflect a escape response towards shallow waters rather than an attempt at increasing crypsisFinancial support was provided by the Spanish Ministry of Science and Innovation (MICINN), Grant CGL2012-40044 to IGM, and by the Universidad Autónoma de Madrid, Short Stay Grant to NPC. Additional financial support was provided by the MICINN, Grant CGL2015-68670-R to NP

Efeitos do Treino de Corrida Moderada na Capacidade de Reparacao da Cartilagem Articular Apos Lesao Mecanica Profunda Estudo Experimental no Rato

The purpose of this study was to investigate if mild running exercise results in improved repair of articular cartilage (AC) full-thickness defects. A perforation was created in a weight-bearing area of the medial femoral condyle in the rate knee. The animals were divided in two groups: intermittent active motion (IAM) and running training (RT) and sacrificed at two periods, four weeks (4wk) and eight weeks (8wk). The nature of the repair tissue besides having improved with time, was better in the training animals. The most common feature observed in the bonding to the adjacent cartilage was the existence of a clear gap between the repair tissue and the residual CA. Concerning the surface congruity the lower index of the RT group at 4 wk might suggest that in the beginning of the repair process a high load magnitude is not beneficial. This study might suggest that, the repair tissue can modulate in response to mechanical loading into a fibrocatilaginous tissue that resembles more the AC in the running animals, as shown by either improved collagen organization or increased amount of collagen (p&lt;0,05-8 wk), and a increased amount of GAG (p&lt;=0,05-4 wk)Available from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1200 Lisboa / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga