The knee flexion-extension angle is an important variable to be monitored in various clinical scenarios, for example, during physical rehabilitation assessment. The purpose of this work is to develop and validate a sensor fusion system based on a knee sleeve for monitoring of physical therapy. The system consists of merging data from two inertial measurement units (IMUs) and an intensity-variation based Polymer Optical Fiber (POF) curvature sensor using a quaternion-based Multiplicative Extended Kalman Filter (MEKF). The proposed data fusion method is magnetometer-free and deals with sensors' uncertainties through reliability intervals defined during gait. Walking trials were performed by twelve healthy participants using our knee sleeve system and results were validated against a gold standard motion capture system. Additionally, a comparison with other three knee angle estimation methods, which are exclusively based on IMUs, was carried out. The proposed system presented better performance (mean RMSE < 3.3°, LFM coefficients, a $_1$ = 0.99 — 0.04, a $_0$ = 0.70 — 2.29, R $^2$ = 0.98 ±0.01 and P $_C$ > 0.99) when compared to the other evaluated methods. Experimental results demonstrate the usability and feasibility of our system to estimate knee motion with high accuracy, repeatability, and reproducibility. This wearable system may be suitable for motion assessment in rehabilitation labs in future studies.

During this case study, the risks of posture, strength and repetition associated with the activity of manual coffee harvesting were evaluated. The sample studied was 26 volunteers who participated in the completion of a Nordic questionnaire, 10 of these were evaluated using observational,and postural tools and 8 people participated in the biomechanical evaluation of postural and muscular load using electromyography and inertial. Seven muscles and two body segments of the upper limbs were evaluated. The goal was to assessthe working conditions of coffee manual harvesting considering ergonomics.The results of the discomfortsweremanifested in the Nordic questionnaire where it was evident that throughout a workday harvesting coffee, the discomfort focuses on the back, lower back, hands,and feet. In the muscle load evaluation was identified that the muscles with the highest activity were the Extensor, Flexor Carpi Ulnar and the trapezius.On average,their muscular activity was20% of their maximum volunteer contraction when performing the statistical analysis. -Tics showed a greater correlation in muscle activationbetween the Carpi Radial Extender and the trapezius. In the postural evaluation of the body segments from the coffee harvesters evaluated, it was identified that they only maintain between 10% and 20% in neutral ranges, so they are always in risky conditions. In conclusion, it is necessary to carry out interventions in the Colombian coffee sector not only because of these evaluated conditions but also for theconditions in theirwork environment.

Este artículo detalla las regulaciones en la calidad del agua en piscinas y agua potable en Alemania, Canadá y Colombia, con una comparación con la regulación existente y los estándares de calidad de las aguas termales. Canadá, Alemania y Colombia regulan que el agua potable debe estar libre de niveles inseguros de sustancias y patógenos, especificando los parámetros microbiológicos y químicos que deben seguirse. Las piscinas en Canadá, Alemania y Colombia tienen regulaciones o estándares específicos para parámetros microbiológicos y químicos que deben seguirse. Al igual que la regulación del agua potable, el agua debe estar libre de organismos patógenos para conservar su calidad de agua. Por otro lado, en el caso de aguas termales donde el bañista tiene condiciones similares a las de las piscinas, Canadá y Alemania no cuentan con regulaciones o normas específicas para el agua de aguas termales. En cambio, se aplican a las aguas termales los mismos requisitos microbianos y químicos que para el agua de piscinas según la Normativa de piscinas públicas de Canadá y la norma Din 19643 de Alemania. Actualmente, Colombia no cuenta con reglamentos o normas sobre la calidad de las aguas termales, tal como lo establece el artículo 6 del Decreto 554 de 2015.

The presence of metals in hot springs has been associated with various adverse health effects. Although some elements are essential for humans, they are dangerous at high levels of exposure. There have been little studies on the presence of metals in hot springs in Colombia, therefore, laboratory tests were carried out over a period of six months (June to December, 2021), with spot samples every month in a ferruginous hot spring in the Cundinamarca region, Colombia. Tests were carried out for arsenic (As), chromium (Cr), mercury (Hg), lead (Pb), aluminum (Al), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), zinc (Zn), strontium (Sr), and calcium (Ca) in the Laboratory of the Bogota Aqueduct and Sewer Company (in Spanish EAAB). Since there are no regulations in Colombia there is no regulation on the quality of hot springs, the analysis of results was carried out by comparing them with standards for drinking water and swimming pools from countries such as Canada, Germany, and the World Health Organization (WHO) as well as hot springs in Japan. It was observed that iron was the only metal that exceeded the regulations for drinking water and swimming pools.