On the function of a female-like signal type in the vibrational repertoire of Enchenopa male treehoppers (Hemiptera: Membracidae).

Animals often mimic the behaviours or signals of conspecifics of the opposite sex while courting. We explored the potential functions of a novel female-like signal type in the courtship displays of male Enchenopa treehoppers. In these plant-feeding insects, males produce plant-borne vibrational advertisement signals, to which females respond with their own duetting signals. Males also produce a signal type that resembles the female duetting responses. We experimentally tested whether this signal modifies the behaviour of receivers. First, we tested whether the female-like signal would increase the likelihood of a female response. However, females were as likely to respond to playbacks with or without them. Second, we tested whether the female-like signal would inhibit competing males, but males were as likely to produce displays after playbacks with or without them. Hence, we found no evidence that this signal has an adaptive function, despite its presence in the courtship display, where sexual selection affects signal features. Given these findings, we also explored whether the behavioural and morphological factors of the males were associated with the production of the female-like signal. Males that produced this signal had higher signalling effort (longer and more frequent signals) than males that did not produce it, despite being in worse body condition. Lastly, most males were consistent over time in producing the female-like signal or not. These findings suggest that condition-dependent or motivational factors explain the presence of the female-like signal. Alternatively, this signal might not bear an adaptive function, and it could be a way for males to warm up or practice signalling, or even be a by-product of how signals are transmitted through the plant. We suggest further work that might explain our puzzling finding that a signal in the reproductive context might not have an adaptive function.

Social Plasticity Enhances Signal-Preference Codivergence.

AbstractThe social environment is often the most dynamic and fitness-relevant environment animals experience. Here we tested whether plasticity arising from variation in social environments can promote signal-preference divergence-a key prediction of recent speciation theory but one that has proven difficult to test in natural systems. Interactions in mixed social aggregations could reduce, create, or enhance signal-preference differences. In the latter case, social plasticity could establish or increase assortative mating. We tested this by rearing two recently diverged species of Enchenopa treehoppers-sap-feeding insects that communicate with plant-borne vibrational signals-in treatments consisting of mixed-species versus own-species aggregations. Social experience with heterospecifics (in the mixed-species treatment) resulted in enhanced signal-preference species differences. For one of the two species, we tested but found no differences in the plastic response between sympatric and allopatric sites, suggesting the absence of reinforcement in the signals and preferences and their plastic response. Our results support the hypothesis that social plasticity can create or enhance signal-preference differences and that this might occur in the absence of long-term selection against hybridization on plastic responses themselves. Such social plasticity may facilitate rapid bursts of diversification.

Leg loss decreases endurance and increases oxygen consumption during locomotion in harvestmen.

Animal movements are highly constrained by morphology and energetics. In addition, predictable bodily damage can constrain locomotion even further. For example, for animals moving on land, losing legs may impose additional costs. We tested if losing legs affects the distance travelled over time (endurance) and the metabolic costs of locomotion (oxygen consumption) in Nelima paessleri harvestmen. These arachnids voluntary releases legs (i.e., autotomy) in response to predation attempts. We used flow-through respirometry as animals moved on a treadmill inside a sealed chamber. We found that endurance decreased gradually with an increasing number of legs lost. Interestingly, oxygen consumption increased only for harvestmen that lost three legs, but not for individuals that lost only a single leg. These results have different ecological and evolutionary implications. Reduced endurance may impair an animal's ability to continue moving away from potential predators, while increased oxygen consumption makes movement costlier. Our findings suggest that individuals have a threshold number of legs that can be lost before experiencing measurable energetic consequences. Overall, our findings illustrate how animals respond to morphological modifications (i.e., damage) that affect the physiology of locomotion.

Robustness to leg loss in Opiliones: A review and framework considerations for future research.

Animals have evolved behavioral and morphological traits that allow them to respond to environmental challenges. However, these traits may have long-term consequences that could impact an animal's performance, fitness, and welfare. Several species in a group of the arachnid order of Opiliones release their legs voluntarily to escape predators. These animals use their legs for locomotion, sensation, and reproduction. Here, we first compile data across species in the suborder Eupnoi, showing that more than half of individuals are found missing legs. Then, we review recent work on the ultimate and proximate implications of leg loss in Opiliones. Field and laboratory experiments showed that leg loss (a) did not affect their survival or mating success and (b) compromised the kinematics and energetics of locomotion, but individuals recovered velocity and acceleration quickly. These findings demonstrate that these animals display robustness, i.e., the ability to withstand and overcome the potential consequences of bodily damage. This may explain why leg loss is so common and prevalent in Opiliones. Additionally, we encourage researchers to consider expanding their hypotheses beyond traditional adaptationist and ableist lenses and incorporate a comprehensive examination of animal welfare when studying animals' responses to bodily damage. Finally, we highlight avenues for future research in Opiliones, namely assessing how individuals move in three-dimensional environments, the neural plasticity aiding recovery post-leg loss, applications for bio-inspired design, and evidence-based animal welfare measures.

Heuristic test reveals little effect of learning and maturation on early prey capture experiences in a web-building spider.

Behaviors can vary throughout an animal's life and this variation can often be explained by changes associated with learning and/or maturing. Currently, there is little consensus regarding how these processes interact to affect behaviors. Here we proposed a heuristic approach to disentangle the effects of learning and maturation on behavior and applied it to the predatory behaviors of Physocyclus globosus spiderlings. We varied the degree of prey difficulty and familiarity spiderlings received along the first instar and across the molt to the second instar and quantified the time spiderlings spent wrapping prey, as a proxy for prey capture efficiency. We found no overall evidence for learning or maturation. Changes in efficiency were mainly due to the switch from difficult to easy prey, or vice versa. However, there was one treatment where spiderlings improved in efficiency before and after the molt, without a switch in prey type. This provides some indication that difficult prey may offer more opportunity for learning or maturation to impact behavior. Although we found little effect of learning or maturation on prey capture efficiency, we suggest that our heuristic approach is effective and could be useful in investigating these processes in other behaviors and other animals.

Moving in an Uncertain World: Robust and Adaptive Control of Locomotion from Organisms to Machine Intelligence.

Whether walking, running, slithering, or flying, organisms display a remarkable ability to move through complex and uncertain environments. In particular, animals have evolved to cope with a host of uncertainties-both of internal and external origin-to maintain adequate performance in an ever-changing world. In this review, we present mathematical methods in engineering to highlight emerging principles of robust and adaptive control of organismal locomotion. Specifically, by drawing on the mathematical framework of control theory, we decompose the robust and adaptive hierarchical structure of locomotor control. We show how this decomposition along the robust-adaptive axis provides testable hypotheses to classify behavioral outcomes to perturbations. With a focus on studies in non-human animals, we contextualize recent findings along the robust-adaptive axis by emphasizing two broad classes of behaviors: 1) compensation to appendage loss and 2) image stabilization and fixation. Next, we attempt to map robust and adaptive control of locomotion across some animal groups and existing bio-inspired robots. Finally, we highlight exciting future directions and interdisciplinary collaborations that are needed to unravel principles of robust and adaptive locomotion.

Bio-inspired design of hard-bodied mobile robots based on arthropod morphologies: a 10 year systematic review and bibliometric analysis.

This research presents a 10-year systematic review based on bibliometric analysis of the bio-inspired design of hard-bodied mobile robot mechatronic systems considering the anatomy of arthropods. These are the most diverse group of animals whose flexible biomechanics and adaptable morphology, thus, it can inspire robot development. Papers were reviewed from two international databases (Scopus and Web of Science) and one platform (Aerospace Research Central), then they were classified according to: Year of publication (January 2013 to April 2023), arthropod group, published journal, conference proceedings, editorial publisher, research teams, robot classification according to the name of arthropod, limb's locomotion support, number of legs/arms, number of legs/body segments, limb's degrees of freedom, mechanical actuation type, modular system, and environment adaptation. During the screening, more than 33 000 works were analyzed. Finally, a total of 174 studies (90 journal-type, 84 conference-type) were selected for in-depth study: Insecta-hexapods (53.8%), Arachnida-octopods (20.7%), Crustacea-decapods (16.1%), and Myriapoda-centipedes and millipedes (9.2%). The study reveals that the most active editorials are the Institute of Electrical and Electronics Engineers Inc., Springer, MDPI, and Elsevier, while the most influential researchers are located in the USA, China, Singapore, and Japan. Most works pertained to spiders, crabs, caterpillars, cockroaches, and centipedes. We conclude that 'arthrobotics' research, which merges arthropods and robotics, is constantly growing and includes a high number of relevant studies with findings that can inspire new methods to design biomechatronic systems.

The type of leg lost affects habitat use but not survival in a non-regenerating arthropod.

Finding shelter and surviving encounters with predators are pervasive challenges for animals. These challenges may be exacerbated after individuals experience bodily damage. Certain forms of damage arise voluntarily in animals; for instance, some taxa release appendages (tails, legs, or other body parts) as a defensive strategy ("autotomy"). This behavior, however, may pose long-term negative consequences for habitat use and survival. Additionally, these putative consequences are expected to vary according to the function of the lost body part. We tested the effects of losing different functional leg types (locomotor or sensory) on future habitat use and survival in a Neotropical species of Prionostemma harvestmen (Arachnida: Opiliones) that undergo frequent autotomy but do not regrow limbs. Daytime surveys revealed that both eight-legged harvestmen and harvestmen missing legs roosted in similar frequencies across habitats (tree bark, mossy tree, or fern), and perched at similar heights. Mark-recapture data showed that harvestmen that lost sensory legs roosted in tree bark less frequently, but on mossy trees more frequently. On the contrary, we did not observe changes in habitat use for eight-legged animals or animals that lost locomotor legs. This change might be related to sensory exploration and navigation. Lastly, we found that recapture rates across substrates were not affected by the type of legs lost, suggesting that leg loss does not impact survival. This potential lack of effect might play a role in why a defensive strategy like autotomy is so prevalent in harvestmen despite the lack of regeneration.

Rapid recovery of locomotor performance after leg loss in harvestmen.

Animals have evolved adaptations to deal with environmental challenges. For instance, voluntarily releasing appendages (autotomy) to escape potential predators. Although it may enhance immediate survival, this self-imposed bodily damage may convey long-term consequences. Hence, compensatory strategies for this type of damage might exist. We experimentally induced autotomy in Prionostemma harvestmen. These arachnids are ideal to examine this topic because they show high levels of leg loss in the field but do not regenerate their legs. We video-recorded animals moving on a horizontal track and reconstructed their 3D trajectories with custom software tools to measure locomotor performance. Individuals that lost either three legs total or two legs on the same side of the body showed an immediate and substantial decrease in velocity and acceleration. Surprisingly, harvestmen recovered initial performance after 2 days. This is the quickest locomotor recovery recorded for autotomizing animals. We also found post-autotomy changes in stride and postural kinematics, suggesting a role for kinematic adjustments in recovery. Additionally, following leg loss, some animals changed the gaits used during escape maneuvers, and/or recruited the 'sensory' legs for locomotion. Together, these findings suggest that harvestmen are mechanically robust to the bodily damage imposed by leg loss.

The ecology and evolution of autotomy.

Autotomy, the self-induced loss of a body part, occurs throughout Animalia. A lizard dropping its tail to escape predation is an iconic example, however, autotomy occurs in a diversity of other organisms. Octopuses can release their arms, crabs can drop their claws, and bugs can amputate their legs. The diversity of organisms that can autotomize body parts has led to a wealth of research and several taxonomically focused reviews. These reviews have played a crucial role in advancing our understanding of autotomy within their respective groups. However, because of their taxonomic focus, these reviews are constrained in their ability to enhance our understanding of autotomy. Here, we aim to synthesize research on the ecology and evolution of autotomy throughout Animalia, building a unified framework on which future studies can expand. We found that the ability to drop an appendage has evolved multiple times throughout Animalia and that once autotomy has evolved, selection appears to act on the removable appendage to increase the efficacy and/or efficiency of autotomy. This could explain why some autotomizable body parts are so elaborate (e.g. brightly coloured). We also show that there are multiple benefits, and variable costs, associated with autotomy. Given this variation, we generate an economic theory of autotomy (modified from the economic theory of escape) which makes predictions about when an individual should resort to autotomy. Finally, we show that the loss of an autotomizable appendage can have numerous consequences on population and community dynamics. By taking this broad taxonomic approach, we identified patterns of autotomy that transcend specific lineages and highlight clear directions for future research.

Intergrative health care method based on combined complementary medical practices: rehabilitative acupuncture, homeopathy and chiropractic.

BACKGROUND: There are various models of health care, such as the epidemiological, psychosocial, sociological, economic, systemic of Neuman, cognitive medicine or ecological, ayurvedic, supraparadigmatic among others. All of them are seeking to combine one or more elements to integrate a model of health care. The article presents a systemic approach to health care with complementary medicines such as rehabilitative acupuncture, homeopathy and chiropractic through the application of a method of holistic care and integrated approach. MATERIALS AND METHODS: There was a participatory action research in January 2012 to January 2013, with a comprehensive approach in 64 patients using the clinical method. We included the environmental aspects, biological, emotional, and behavioral to identify, recognize and integrate the form of manifestation of the disease. Later, it was ordered in a coherent way the etiologic factors, precipitating factors and identified the vulnerability of the patients as well as the structural alterations, classifying them in immediate, mediate and late. Referred to the three disciplines: rehabilitative acupuncture, homeopathy and chiropractic to be seen doing references and against-references between them, evaluating the current state of health and each meeting by noting the clinical and behavioral changes submitted and thus the area of attention to which would be forwarded to continue their treatment. RESULTS: 64 patients rotated by the 3 areas taking an average of 30 meetings with rehabilitative acupuncture, 12 with homeopathy and 10 with chiropractic. The changes were submitted clinical attitudinal, behavioral, clinical and organic. CONCLUSIONS: The model of care was multifaceted and interdisciplinary with a therapeutic approach of individualization and a holistic view to carry out a comprehensive diagnosis and provide quality health care to the population.

Multimodal sensory reliance in the nocturnal homing of the amblypygid Phrynus pseudoparvulus (Class Arachnida, Order Amblypygi)?

Like many other nocturnal arthropods, the amblypygid Phrynus pseudoparvulus is capable of homing. The environment through which these predators navigate is a dense and heterogeneous tropical forest understory and the mechanism(s) underlying their putatively complex navigational abilities are presently unknown. This study explores the sensory inputs that might facilitate nocturnal navigation in the amblypygid P. pseudoparvulus. Specifically, we use sensory system manipulations in conjunction with field displacements to examine the potential involvement of multimodal - olfactory and visual - stimuli in P. pseudoparvulus' homing behavior. In a first experiment, we deprived individuals of their olfactory capacity and displaced them to the opposite side of their home trees (<5m). We found that olfaction-intact individuals were more likely to be re-sighted in their home refuges than olfaction-deprived individuals. In a second experiment, we independently manipulated both olfactory and visual sensory capacities in conjunction with longer-distance displacements (8m) from home trees. We found that sensory-intact individuals tended to be re-sighted on their home tree more often than sensory-deprived individuals, with a stronger effect of olfactory deprivation than visual deprivation. Comparing across sensory modality manipulations, olfaction-manipulated individuals took longer to return to their home trees than vision-manipulated individuals. Together, our results indicate that olfaction is important in the nocturnal navigation of P. pseudoparvulus and suggest that vision may also play a more minor role.

Enfermedades actuales asociadas a los factores de riesgo laborales de la industria de la construcción en México / Current diseases associated with the workplace risk factors of the construction industry in Mexico

La industria de la construcción es sin lugar a dudas una de las mayores generadoras de riesgos de trabajo, sin embargo, los programas de prevención no hacen evidente dicha situación. Los trabajadores de la industria de la construcción laboran bajo condiciones precarias, carecen de seguridad social, y desconocen por completo los derechos que les son consignados por ley pese a no firmar un contrato. Es imprescindible que dichos trabajadores y los responsables de su actividad laboral, conozcan los factores de riesgo a que se encuentran expuestos, pero sobre todo las graves afecciones a la salud que estos pueden provocar, que van más allá de las lesiones músculo-esqueléticas incapacitantes tan reconocidas en bibliografía. Conforme se establezca la necesidad de un adecuado diagnóstico situacional al interior de las industrias, la prevención de patologías que hoy se consideran meramente generales y cuyo origen se encuentra en el desempeño del trabajo, encaminará a la salud pública a la adopción de políticas en mejora de las condiciones del mismo. Objetivo: Identificar las enfermedades actuales que se asocian a los factores de riesgo de la industria de la construcción en México. Material y Métodos: Revisión bibliográfica publicada desde enero del 2000 hasta noviembre del 2016 en bases de datos: PUBMED, SciELO y Medline. Se consultaron bibliografías tanto en inglés como en español. Las palabras clave consideradas en la búsqueda incluyeron: industria de la construcción, factores de riesgo, trabajo, enfermedades. Conclusiones: La industria de la construcción al presentar mayor cantidad de riesgos ergonómicos en México, debería ser una de las más estrechamente vigiladas, epidemiológicamente hablando, pues de ella derivan un gran número de enfermedades que aquejan a la población y que saturan diariamente al sistema de salud de nuestro país además de que afecta al desarrollo económico debido a la disminución del rendimiento y el ausentismo de los trabajadores afectados. La exigencia de dicha vigilancia epidemiológica efectuada por las autoridades del trabajo tendrían que redundar en mejoras de las condiciones al interior de los centros de trabajo, es decir, desde equipar a los trabajadores de herramientas aptas y específicas para su actividad, dotarlos con equipo de protección personal acorde a su anatomía y con las características específicas para los tipos de factores y sustancias a las que se exponen, así como la reingeniería de los procesos de construcción, obsoletos o artesanales, con tecnología. Pero sobre todo comunicar y mantener informados a los trabajadores acerca de los riesgos a que están expuestos por el tipo de actividad laboral que desempeñan. Es fundamental que en este compromiso de vigilancia se tejan relaciones internas estrechas y formales entre los trabajadores y los patrones, pero también es fundamental que se genere un compromiso transectorial en materia de legislación y normatividad para que verdaderamente se apliquen y cumplan las obligaciones, deberes y derechos que garanticen un trabajo digno para este sector de la población (AU)

The construction industry is undoubtedly one of the biggest generators of work risks; however, prevention programs do not make this situation evident. Workers in the construction industry work in precarious conditions, lack social security, and are completely unaware of their rights that are enshrined in them despite not signing a contract. It is imperative that both these workers and those responsible for their work, know the risk factors they are exposed to, but above all the serious health conditions they can cause, which go beyond the disabling musculoskeletal injuries so detailed in the bibliography. As the need for an adequate situational diagnosis within the industries is established, the prevention of pathologies considered merely general and whose origin is in the performance of the work, will lead the public health to the adoption of policies in improvement of the conditions thereof. Objectives: Identify the current diseases that are associated with the risk factors of the construction industry in Mexico. Material and Methods: Bibliographic review published from January 2000 to November 2016 in PUBMED, SciELO and Medline databases. Bibliographies were consulted in both English and Spanish. The keywords considered in the search included: construction industry, risk factors, work, diseases. Conclusions: The construction industry, presenting more ergonomic hazards in Mexico, should be one of the most closely monitored, epidemiologically speaking, because of it derives a large number of diseases that afflict the population and saturate daily the health system of Our country. It affects as well the economic development due to decreased performance and absenteeism of affected workers. The demand for such epidemiological surveillance by the labor authorities should result in improved conditions within the workplace, from equipping workers suitable and specific tools for their activity, provide them with protective equipment personnel according to their anatomy and with the specific characteristics for the types of factors and substances to which they are exposed, as well as the reengineering of obsolete or artisanal construction processes with technology. But above all, communicate and keep workers informed about the risks they are exposed to by the type of work activity they perform. It is essential that this commitment to oversee close and formal internal relationships between workers and employers, but it is also essential that a cross-sectoral commitment on legislation and regulations is created to truly implement and fulfill the obligations, duties and Rights that guarantee decent work for this sector of the population (AU)

Evaluación inicial de parámetros de campo en un biodigestor anaeróbico para el tratamiento de aguas residuales / Preliminary evaluation of field parameters at an anaerobic biodigester designed for the treatment of wastewater

El biodigestor anaerobio utilizado en este estudio, se diseñó para tratar agua residual doméstica en un sanitario de prueba, y se caracteriza por ser de: flujo continuo, baja carga orgánica y tener cuatro etapas de proceso. La importancia del prototipo estudiado radicó en las condiciones reales en que se probó. La primera etapa consistió en la selección del sitio, construcción del prototipo en ferrocemento con capacidad de 1m³, impermeabilización y carga. En esta etapa se inoculó el reactor con materia orgánica procedente de las descargas del sanitario, durante el periodo de agosto a diciembre de 2011. La evaluación de este periodo consistió en la medición de parámetros de campo: pH, conductividad eléctrica, sólidos sedimentables, temperatura del influente - efluente y oxígeno disuelto del sistema que permitieron verificar el comportamiento del proceso del digestor durante la fase de arranque. Los resultados obtenidos para estas determinaciones a la entrada y salida del biodigestor respectivamente son los siguientes: pH (8.03; 8.43), conductividad eléctrica (1510.83 µS/cm; 1207.00 µS/cm), temperatura del proceso (19.2°C; 20.1°C), sólidos sedimentables (144.5mL/L; 0.02mL/L), oxígeno disuelto (4.5992 mg/L; 0.1924 mg/L) estos datos proporcionaron un punto de partida para el tratamiento de aguas residuales de tipo doméstica.

The anaerobic biodigester analyzed in the present study was designed for the treatment of domestic wastewater in a test restroom, characterized by its continuous flow, low organic load and a four-stage processing system. The value of the prototype under research consists in the real daily conditions under which it was tested. The first stage consisted of the site selection, and the manufacture of a waterproof iron reinforced cement prototype, with a 1m³ loading capacity. At this stage, during the period from august to december 2011, the reactor was inoculated with organic matter originating from the aforementioned restroom discharges. The evaluation of this stage consisted in taking measurements of the following field parameters: pH, electrical conductivity, sedimentable solids, and inflow and outflow temperature along the system. These records substantiated the behaviour of the processes within the digester during the starting phase. The results obtained through these determinations at both the biodigester entry and exit points are respectively: pH (8.03; 8.43), electrical conductivity (1510.83 µS/cm; 1207.00 µS/cm), inflow and outflow temperatures (19.2°C; 20.1°C), sedimentable solids (144.5mL/L; 0.02mL/L) and dissolved oxygen (4.5992 mg/L; 0.1924 g/L). These data provided a starting point for the treatment of domestic wastewater.

Diagnóstico de factores de riesgo relacionados con la accidentabilidad de mano en trabajadores de una empresa refresquera / Diagnostic of risk factor related to the accidentes of hand in workers of solf-drinks industry

Con el propósito de que se profundice en el reconocimiento de factores de riesgos derivados de este tipo de empresas y de estas actividades específicamente, para que se prevengan y minimicen los efectos a la salud de forma integral al interior de las empresas, el presente trabajo pretende determinar los factores de riesgo potencialmente relacionados con los accidentes de mano. Objetivos: Determinar los factores de riesgo relacionados con los accidentes en mano para identificar que permitan disminuir la posibilidad de accidentes de mano mediante la modificación, eliminación y/o control de los factores presentes. Material y métodos: Estudio observacional, descriptivo y longitudinal llevado a cabo en la población trabajadora del área de ventas, compuesta por 206 ayudantes y 81 agentes, de una Cooperativa productora Bebidas frutales de la Ciudad de México, en el periodo de 2007-2009. Se empleó el Método de Freeman Modificado para el Diagnóstico Situacional. Resultados: Los factores de riesgo relacionados con accidentes de mano identificados y jerarquizados son: en primer lugar los psicosociales derivados de Organización Laboral (ritmo acelerado de la actividad) y la Condición Insegura (traslado del personal en la defensa trasera del camión); en segundo lugar se encontraron los Ergonómicos (movimientos repetitivos, manejo manual de cargas), junto con el Acto Inseguro (omisión del uso del equipo de protección personal), y la Condición Insegura (tipo de unidad, puerta y material transportado; y falta de capacitación); finalmente en tercer lugar los psicosociales de Organización Laboral (jornada indefinida mínima de 8 horas máxima de 14) y Condición Insegura (objetos punzocortantes en cajas). Conclusiones: Los accidentes de mano constituyen un problema de salud pública importante a nivel nacional e internacional. Es de suma importancia identificar los factores de riesgo que se relacionan con su génesis como son: los factores psicosociales, condiciones inseguras, factores ergonómicos y actos inseguros. Por lo que se considera que estos, se deben buscar intencionadamente en las empresas dedicadas a este rubro de actividades, y evidenciarlos cuando se pretendan disminuir este tipo de accidentes y generar medidas preventivas y correctivas para mejorar la calidad de vida del trabajador y el rendimiento del mismo en sus labores (AU)

With the purpose of deepen on the recognize of risk factors from this kind of business and from this specific activities, to prevent and minimize the health effects integrally at the industries, the present work pretend to determine the risk factors potentially related with hand accidents. Objective: Determine the risk factors related to the accidents of hand to identify and establish the risks allowing decrease the possibility of accidents in hand through the modification, elimination and or control of present factors. Material and methods: Observational, descriptive and longitudinal study develop in worker population of sales area, composed by 206 helpers and 81 agents, cooperative producers of soft drinks and carbonated beverages in México City, in a period between 2007-2009. Was employed the Freeman Modified Method for the Situational Diagnostic. Results: The risk factor related to hand accidents determined by the application of Freeman Modified Method in sales area according to the organization: were first derived from the psychosocial labor organization (accelerated pace of activity) and the Insecure Condition (transfer of the personnel within the rear bumper of the truck); second were found ergonomics (repetitive movements and manual handling of loads), along with Insecure Act (omission of the use of personal protection equipment), and the Insecure Condition (kind of unity, door and material transported, and lack of training); finally, in third psychosocial of Labor Organization (indefinite at least 8 hours maximum of 14) and unsafe (sharp boxes). Conclusions: The risk factors presents in the generation of hand accidents in sales area of a soft drink industry are: primarily psychosocial factors due to the rhythm of the activity; unsafe condition due to lack of safety regulation. In second place ergonomic factors and unsafe acts by omission of use of personal protective equipment and unsafe condition, specifically lack of training and use of unsafe resources provided to the worker. Third place, psychosocial factors due to over 8 hours and under 14 hours working day. Mentioned risk factors should be diagnosed promptly and to evidence in companies engages in the production of fruit drinks and carbonated, which seek to reduce work accidents though preventive and corrective measures (AU)