Effects of tailored lateral wedge insoles on medial knee osteoarthritis based on biomechanical analysis: 12-week randomized controlled trial.

BACKGROUND: Lateral wedge insoles adjusted by biomechanical analysis may improve the condition of patients with medial knee osteoarthritis. DESIGN: This is a prospective, randomized, controlled, single-blind clinical trial. SETTING: The study was conducted in a biomechanics laboratory. SUBJECTS: A total of 38 patients with medial knee osteoarthritis were allocated to either an experimental group (lateral wedge insoles) or a control group (neutral insoles). INTERVENTIONS: Experimental group (n = 20) received an adjusted lateral wedge insole of 2, 4, 6, 8, or 10 degrees, after previous biomechanical analysis. Control group (n = 18) received a neutral insole (0 degrees). All patients used the insoles for 12 weeks. MAIN MEASURES: Visual analogue scale, Knee Injury and Osteoarthritis Outcome Score questionnaire, biomechanical parameters: first and second peak of the external knee adduction moment and knee adduction angular impulse, and physical performance tests: 30-second sit-to-stand test, the 40-m fast-paced walk test, and the 12-step stair-climb test. RESULTS: After 12 weeks, between-group differences did not differ significantly for pain intensity (-12.5 mm, (95% CI -29.4-4.4)), biomechanical parameters (p = 0.05), Knee Injury and Osteoarthritis Outcome Score, and physical performance tests, except on the Knee Injury and Osteoarthritis Outcome Score subscale other symptoms (p = 0.002; 13.8 points, (95% CI 5.6-22.0)). CONCLUSION: Tailored wedge insoles were no more effective at improving biomechanical or clinically meaningful outcomes than neutral insoles, except on symptoms. More participants from the experimental group reported they felt some improvement. However, these effects were minimal and without clinical significance.

Optical Fiber Temperature Sensors and Their Biomedical Applications.

The use of sensors in the real world is on the rise, providing information on medical diagnostics for healthcare and improving quality of life. Optical fiber sensors, as a result of their unique properties (small dimensions, capability of multiplexing, chemical inertness, and immunity to electromagnetic fields) have found wide applications, ranging from structural health monitoring to biomedical and point-of-care instrumentation. Furthermore, these sensors usually have good linearity, rapid response for real-time monitoring, and high sensitivity to external perturbations. Optical fiber sensors, thus, present several features that make them extremely attractive for a wide variety of applications, especially biomedical applications. This paper reviews achievements in the area of temperature optical fiber sensors, different configurations of the sensors reported over the last five years, and application of this technology in biomedical applications.

Comparison of Morphological Profiles and Performance Variables between Female Volleyball Players of the First and Second Division in Portugal.

Knowledge of players' anthropometric profiles may contribute to a better understanding of the differences between their performance levels. For example, vertical jump height, which is a major indicator of a volleyball player's performance, is influenced by favorable anthropometric variables. This study's aim was to describe anthropometric profiles of elite female volleyball players competing in the 1st and 2nd divisions in Portugal and to link these profiles with performance skills such as jump height obtained during blocking and spiking actions. Fifty-nine volleyball players were analyzed according to their competitive level, forming three independent groups: GA (n = 20, A1 division, ranked first), GB (n = 21, A1 division, ranked last) and GC (n = 18, A2 division). Anthropometric data collected included body mass and height, arm span, seven skinfolds (triceps, biceps, subscapular, suprailiac, abdominal, thigh and calf), four body perimeters (relaxed brachial, contracted brachial, thigh and calf), and two body diameters (humeral and femoral). Performance data included the height obtained during block and spike actions. Significant differences were found between groups (GA/GB from A1 and GC from A2). Players in the GA had the highest body mass (68.05 ± 6.62 kg, p < 0.05), body height (176.35 ± 6.21 cm, p < 0.05), arm span (177.59 ± 6.09 cm, p < 0.05), lean mass (53.51 ± 4.94 kg, p < 0.05) and vertical jump heights (block: 0.36 ± 0.06 m and spike: 0.43 ± 0.05 m, p < 0.05). As expected, the fat mass percentage of GA players was the lowest (21.30 ± 2.61%). The results suggest that anthropometric profiles of volleyball players may vary according to the competitive level. The higher body mass, body height, arm span, and lean mass presented by GA players in comparison with GC players suggest these variables are important for top-level performance, since these athletes also exhibited higher jump heights. Variables such as height and arm span have a considerable genetic influence and could be important for early talent identification in volleyball. Other variables such as body mass, lean mass and vertical jump performance are more complex, since they also reflect the effects of environmental and training conditions.

The optimal degree of lateral wedge insoles for reducing knee joint load: a systematic review and meta-analysis.

BACKGROUND: Lateral wedge insoles are traditionally used to reduce the adduction moment that crosses the knee during walking in people with medial knee osteoarthritis. However, the best degree to reduce knee joint load is not yet well established. METHODS: Electronic databases were searched from their inception until May 2017. Included studies reported on the immediate biomechanical effects of different degrees of lateral wedge insoles during walking in people with knee osteoarthritis. The main measures of interest relating to the biomechanics were the first and second peak of external knee adduction moment and knee adduction angular impulse. For the comparison of the biomechanical effects of different degrees of insoles, the studies were divided in three subgroups: insoles with a degree higher than 0° and equal to or lower than 5°; insoles higher than 5° and equal to or lower than 9°; and insoles higher than 9°. Eligible studies were pooled using random-effects meta-analysis. RESULTS: Fifteen studies with a total of 415 participants met all eligibility criteria and were included in the final review and meta-analysis. The overall effect suggests that lateral wedge insoles resulted in a statistically significant reduction in the first peak (standardized mean difference [SMD] -0.25; 95% confidence interval [CI] -0.36, - 0.13; P < 0.001), second peak (SMD -0.26 [95% CI -0.48, - 0.04]; P = 0.02) and knee adduction angular impulse (SMD -0.17 [95% CI -0.31, - 0.03]; P = 0.02). The test of subgroups found no statistically significant differences. CONCLUSION: Systematic review and meta-analysis suggests that lateral wedge insoles cause an overall slight reduction in the biomechanical parameters. Higher degrees do not show higher reductions than lower degrees. Prior analysis of biomechanical parameters may be a valid option for selecting the optimal angle of wedge that best fits in knee osteoarthritis patients with the lowest possible degree.

Effects of the Pitch Surface on Displacement of Youth Players During Soccer Match-Play.

The aim of this study was to analyze the effect of different pitch surfaces (artificial turf, natural turf and dirt field) on positioning and displacement of young soccer players (age: 13.4 ± 0.5 yrs; body height: 161.82 ± 7.52 cm; body mass: 50.79 ± 7.22 kg and playing experience: 3.5 ± 1.4 yrs). Data were collected using GPS units which allowed to calculate spatial distribution variability, assessed by measuring entropy of individual distribution maps (ShannEn). Ellipsoidal areas (m2) representing players' displacement on the pitch, centred on the average players' positional coordinates, were also calculated, with axes corresponding to the standard deviations of the displacement in the longitudinal and lateral directions. Analysis of variance (ANOVA) was used to evaluate differences between pitch surfaces and across players' positions. There was significant effect in positioning (η2 = 0.146; p < 0.001) and displacement (η2 = 0.063; p < 0.05) by the players between pitch surfaces. A dirt field condition induced an increase in the players' movement variability, while players' displacement was more restricted when playing on artificial turf. Also, there were significant effects on positioning (η2 = 0.496; p < 0.001) and displacement (η2 = 0.339; p < 0.001) across players' positions. Central midfielders presented the greatest movement variability and displacement while fullbacks showed the lowest variability. Subsequently, the results may contribute to implement strategies that optimise players' performance in different surface conditions.

Fabry-Perot cavity based on silica tube for strain sensing at high temperatures.

In this work, a Fabry-Perot cavity based on a new silica tube design is proposed. The tube presents a cladding with a thickness of ~14 µm and a hollow core. The presence of four small rods, of ~20 µm diameter each, placed in diametrically opposite positions ensure the mechanical stability of the tube. The cavity, formed by splicing a section of the silica tube between two sections of single mode fiber, is characterized in strain and temperature (from room temperature to 900 °C). When the sensor is exposed to high temperatures, there is a change in the response to strain. The influence of the thermal annealing is investigated in order to improve the sensing head performance.

In vivo measurement of the pressure signal in the intervertebral disc of an anesthetized sheep.

The purpose of the present study was to measure the intradiscal pressure signal of an anesthetized sheep under spontaneous breathing. An ultra-miniature fiber optic high-pressure sensor was implanted into the nucleus pulposus of the fifth lumbar intervertebral using a dorsolateral transforaminal approach. Results suggested the periodicity of the intradiscal pressure signal was similar to the mean respiratory rate of the animal. The average resting intradiscal pressure was also calculated and compared to available data.

From conventional sensors to fibre optic sensors for strain and force measurements in biomechanics applications: a review.

In vivo measurement, not only in animals but also in humans, is a demanding task and is the ultimate goal in experimental biomechanics. For that purpose, measurements in vivo must be performed, under physiological conditions, to obtain a database and contribute for the development of analytical models, used to describe human biomechanics. The knowledge and control of the mechanisms involved in biomechanics will allow the optimization of the performance in different topics like in clinical procedures and rehabilitation, medical devices and sports, among others. Strain gages were first applied to bone in a live animal in 40's and in 80's for the first time were applied fibre optic sensors to perform in vivo measurements of Achilles tendon forces in man. Fibre optic sensors proven to have advantages compare to conventional sensors and a great potential for biomechanical and biomedical applications. Compared to them, they are smaller, easier to implement, minimally invasive, with lower risk of infection, highly accurate, well correlated, inexpensive and multiplexable. The aim of this review article is to give an overview about the evolution of the experimental techniques applied in biomechanics, from conventional to fibre optic sensors. In the next sections the most relevant contributions of these sensors, for strain and force in biomechanical applications, will be presented. Emphasis was given to report of in vivo experiments and clinical applications.

Review of fiber-optic pressure sensors for biomedical and biomechanical applications.

As optical fibers revolutionize the way data is carried in telecommunications, the same is happening in the world of sensing. Fiber-optic sensors (FOS) rely on the principle of changing the properties of light that propagate in the fiber due to the effect of a specific physical or chemical parameter. We demonstrate the potentialities of this sensing concept to assess pressure in biomedical and biomechanical applications. FOSs are introduced after an overview of conventional sensors that are being used in the field. Pointing out their limitations, particularly as minimally invasive sensors, is also the starting point to argue FOSs are an alternative or a substitution technology. Even so, this technology will be more or less effective depending on the efforts to present more affordable turnkey solutions and peer-reviewed papers reporting in vivo experiments and clinical trials.