Effect of different flooring types on pressure distribution under the bovine claw - an ex vivo study

BACKGROUND

Mechanical interactions between hard floorings and the sole of bovine claws can be reasonable to cause traumatic claw lesions. In this ex vivo study, the direct kinetic impact of concrete and three types of rubber mats on the sole of dairy cattle claws was analyzed. In order to apply uniform loads, isolated distal hind limbs of adult Holstein Friesian dairy cows were functionally trimmed according to the Dutch method and attached to a load applicator. Kinetic data were recorded using a thin, foil-based pressure measurement system (Hoof™ System, Tekscan®).

RESULTS

On concrete, the load distribution between the lateral and medial claw was less balanced than on the rubber floorings. The loaded area was significantly smaller on concrete (32.2 cm2) compared to all rubber mats (48.3-58.0 cm2). Average pressures (Pav) and maximum pressures (Pmax) were significantly higher on concrete (Pav 44.7 N/cm2; Pmax 130.3 N/cm2) compared to the rubber floorings (Pav 24.9-29.7 N/cm2; Pmax 71.9-87.2 N/cm2). Pressure peaks occurred mainly in plantar and abaxial parts of the lateral claw and in apical and plantar regions of the medial claw. Load distribution displayed a widely unloaded slope region, but considering the pressure distribution under the claw, none of the zones showed a generally lower pressure exposure.

CONCLUSIONS

Altogether, rubber floorings lead to a significant mechanical relief of the sole compared to concrete. Furthermore, relevant differences between the tested rubber mats could be determined. Therefore the used system may be applied to compare further flooring types.

Investigation of human body potential measured by a non-contact measuring system

A human body is occasionally electrified in a room. This charged object will be a source of electrostatic accidents, including the malfunction of electronic equipment. Hence, prevention of these accidents is required. Accidents occasionally occur, even though antistatic clothes and shoes are used. One of the causes for these accidents is that there is a lack of the preventive measures. This situation occurs when using, for example, unconductive wax. In this study, human body potential (voltage) is measured using a non-contact measuring system. An investigation of the human body's voltage when using this system is conducted. The result demonstrates that the voltage of a human body wearing antistatic clothes and shoes or light clothes and slippers exceeds a malfunctioning voltage of a microelectronics device when the body walks on floors. Thus, accidents may occur even if a human body wearing the antistatic clothes walks on flooring. These results will be useful in estimating determination whether electrostatic accidents occur or not.

Can we make a carpet smart enough to detect falls?

In this paper, we have enhanced smart carpet, which is a floor based personnel detector system, to detect falls using a faster but low cost processor. Our hardware front end reads 128 sensors, with sensors output a voltage due to a person walking or falling on the carpet. The processor is Jetson TK1, which provides more computing power than before. We generated a dataset with volunteers who walked and fell to test our algorithms. Data obtained allowed examining data frames (a frame is a single scan of the carpet sensors) read from the data acquisition system. We used different algorithms and techniques, and varied the windows size of number of frames (WS ≥ 1) and threshold (TH) to build our data set, which later used machine learning to help decide a fall or no fall. We then used the dataset obtained from applying a set of fall detection algorithms and the video recorded for the fall pattern experiments to train a set of classifiers using multiple test options using the Weka framework. We measured the sensitivity and specificity of the system and other metrics for intelligent detection of falls. Results showed that Computational Intelligence techniques detect falls with 96.2% accuracy and 81% sensitivity and 97.8% specificity. In addition to fall detection, we developed a database system and web applications to retain these data for years. We can display this data in realtime and for all activities in the carpet for extensive data analysis any time in the future.

Validation of Mobility of Pedestrians with Low Vision Using Graphic Floor Signs and Voice Guides

Some people with low vision or elderly persons tend to walk while watching a nearby floor, therefore, they often overlook or hard to read suspended signs. In this study, we propose two kinds of voice guides, and an experiment is conducted by participants with low vision using these voice guides and graphic floor signs in order to investigate effectiveness of these combinations. In clock position method (CP), each direction of near facilities are described in using an analogy of a 12-hour clock. Meanwhile, in numbering method (NU), near facilities are put the number in clockwise order, however, each direction are only illustrated in a crossing sign. As a result of an experiment, it is showed that both voice guides are effective for pedestrians with low vision. NU is used as a complement of graphic floor signs. Meanwhile, CP is used independently with graphic floor signs, however, there is a risk in the case of using in the environment where pedestrians are easy to mistake the reference direction defined by the sounding speaker.

A Probabilistic Neural Network Model for Lameness Detection

A 4-balance system for measuring the leg-load distribution of dairy cows during milking to detect lameness was developed. Leg weights of 73 cows were successfully recorded during almost 10,000 robotic milkings over a period of 5 mo. Cows were scored weekly for locomotion, and lame cows were inspected clinically for hoof lesions. Unsuccessful measurements, caused by cows standing outside the balances, were removed from the data with a special algorithm, and the mean leg loads and number of kicks during milking were calculated. To develop an expert system to automatically detect lameness cases, a model was needed, and a classifying probabilistic neural network model was chosen for the task. The data were divided into 2 parts and 5,074 measurements from 37 cows were used to train a classifying probabilistic neural network model. The operation of the model was evaluated for its ability to detect lameness in the validating data set, which had 4,868 measurements from 36 cows. The model was able to classify 96.2% of the measurements correctly as sound or lame cows, and 100% of the lameness cases in the validation data were identified. The number of measurements (equal to the number of milkings) causing false alarms was 1.1%. The model developed has the potential to be used as an on-farm decision aid and can be used in a real-time lameness monitoring system.

Association between floor type and behaviour, skin lesions, and claw dimensions in group-housed fattening bulls

Rubber mats covering concrete slatted flooring are a developing market in dairy barns but remain rare in beef cattle facilities. The aim of this study was to investigate the effects of covering slatted concrete floor with perforated rubber mats on behaviour and occurrence of skin and claw lesions in fattening bulls. The groups of six bulls each with a total average age of 9.8 months were kept over 1 year on either slatted concrete (CONCRETE PEN) or on slatted concrete covered completely (RUBBER PEN) or partially (CHOICE PEN) with perforated rubber mats. Every quarter-year, behaviour (preference of flooring, lying, aggression, mounting) was recorded. In two-weekly intervals the incidence of skin lesions was examined. At 12 and 18 months of age the rising time of the bulls was measured. At the beginning of the study and after slaughter claw dimensions were recorded. Bulls in the CHOICE PEN preferred (P<0.01) the rubber coated area throughout the experiment. Animals in the RUBBER and the CHOICE PENS showed more lying periods (P<0.01) and had a lesser incidence of skin lesions (P<0.01) compared to bulls in the CONCRETE PEN. Bulls in the CHOICE PEN needed less time for rising (2.7+/-0.3s) than bulls in the CONCRETE PEN (4.4+/-0.5s, P<0.01). Net claw growth differed significantly between all pens (RUBBER>CHOICE>CONCRETE; P<0.05). In conclusion, the results of this study indicate that rubber coated slatted flooring has a positive influence on the housing conditions of beef cattle.

Effects of roughness and compressibility of flooring on cow locomotion

We examined the effects of roughness and degree of compressibility of flooring on the locomotion of dairy cows. We observed 16 cows walking down specially constructed walkways with materials that differed in surface roughness and degree of compressibility. Use of a commercially available soft rubber flooring material decreased slipping, number of strides, and time to traverse the corridor. These effects were most apparent at difficult sections of the corridor, such as at the start, at a right-angle turn, and across a gutter. Covering the walkway with a thin layer of slurry increased frequency of slipping, number of strides, and time taken to traverse the walkway. Effects of adding slurry were not overcome by increasing surface roughness or compressibility. Placing more compressible materials under a slip-resistant material reduced the time and number of steps needed to traverse the corridor but did not reduce slips, and the effects on cow locomotion varied nonlinearly with the degree of compressibility of the floor. Use of commercially available rubber floors improved cow locomotion compared with concrete floors. However, standard engineering measures of the floor properties may not predict effects of the floor on cow behavior well. Increasing compressibility of the flooring on which cows walk, independently of the roughness of the surface, can improve cow locomotion.

Concrete floor-bovine claw contact pressures related to floor roughness and deformation of the claw

The intention of this research was to study the impact of concrete floor surface roughness on a bovine claw model and to assess the deformation of the bovine claw model under load. The pressure distribution between the floor and the claw is the key method in this research. Monitoring foot-to-ground pressure distributions may provide insight into the relation between high local pressures and foot lesions. Concrete floor samples were made with 5 different finishing methods. Their roughness was determined by measuring the heights of the "peaks and the valleys" of the surface with a high-precision laser beam. The smoothest surface was the sample finished with a metal float (surface roughness R(a) = 0.062 mm) and the roughest surface occurred with the heavily sandblasted sample (surface roughness R(a) = 0.488 mm). The roughness of the concrete floor samples was related to the mean and peak contact pressures that can occur in a laboratory test bench between floor and bovine claw. It was found that the claw itself has approximately 2 times more effect on these contact pressures than the surface roughness. Peak pressures found were high enough (up to 111 MPa) to cause damage to the bovine claw sole horn. The strains occurring in the horn wall were measured and related to the floor-finishing method and the load. Strain gauge measurements indicated that it is difficult to predict what kind of deformation of the claw wall will occur at a certain location. Different strains will occur for different floor-finishing methods. The corresponding stresses in the horn wall did not exceed the yield stress (14 and 11 MPa for dorsal and abaxial wall horn, respectively).

Does a rolling floor reduce the physical work demands and workload, and increase the productivity of truck drivers handling packed goods?

A PCM rolling floor (RF) was developed to reduce the risk of musculoskeletal complaints among truck drivers. The RF can be used to move packed goods automatically in and out of the cargo space. The efficacy of this intervention on physical work demands, energetic and perceived workload and productivity was evaluated by comparing nine truck drivers working with a RF and a traditional, non-moving floor during a working day. Since the RF was not used during the loading process, no effects were found. The RF reduced the unloading process by 8 min, decreased the frequency of lifting and setting down goods by 24%, decreased the frequency of handling goods below knee level by 79%, and decreased the frequency of entering the cargo space by 45%. No effect was found on the energetic and perceived workload. The RF resulted in a small increase in productivity.

Reducing employee slips, trips, and falls during employee-assisted patient activities

Following a remodeling of patient care rooms at Mary Free Bed Rehabilitation Hospital, the nursing staff reported frequent slipping in patient care areas. Data were analyzed and revealed that most slips were occurring during transfer of patients from shower chairs. An extensive literature review was done, and solutions to slipping were sought from areas outside of the healthcare industry. Specifically, ideas were borrowed from the commercial fishing industry and the restaurant industry. Both industries rely heavily on footwear to reduce slipping in the workplace. A trial was initiated with nursing staff members wearing positive-grip shoe covers that can be worn over regular footwear. No slips occurred during the trial. The purpose of this article is to motivate nurses who are involved in transferring patients from shower chairs (often used in rehabilitation settings) to consider the role their footwear has in reducing slips and potential injury.

Prevalence of claw disorders in Dutch dairy cows exposed to several floor systems

Claw health was examined in an observational study on Dutch dairy farms with either a slatted floor (SL), slatted floor with manure scraper (SL-SCR), solid concrete floor (SCF), a straw yard (SY), or a zero-grazing feeding system (ZG). Hooves of cows' hind legs were examined for the presence and severity of claw disorders during hoof trimming events at the end of the pasture (P-study) and housing period (H-study). The number of cows in each study was 3078 (49 herds) and 3190 (47 herds), respectively. Due to a different hoof trimming strategy, data collected during both observation periods in SY herds (638 cows; 16 herds) were combined. Cows in straw yards (SY) had by far the lowest numbers of claw disorders. Over 80% of cows exposed to concrete flooring had at least one claw disorder at the time of observation, whereas on SY surfaces, this percentage was between 55 and 60. Cows on SL-SCR were less frequently affected by interdigital dermatitis/heel erosion (IDHE) and digital dermatitis (DD) than cows on SL (reference floor system). Little difference in claw health was found between SF and SL. The ZG cows were at higher risk (OR > 2) for most claw disorders in the P-study, whereas in the H-study, ZG cows showed less IDHE, sole hemorrhage, and sole ulcer. All herds on concrete flooring (SL, SL-SCR, SCF, ZG) were infected by DD, resulting in an average cow level prevalence of 30%. This indicates that the level of DD infection has increased considerably over the last 10 yr in The Netherlands.

A study on an energy supply method for a transcutaneous energy transmission system

This study proposes a new type of a transcutaneous energy transmission system (TETS) that can supply electrical power for an implanted device without an external battery. In this system, the power is supplied from the floor to the shoes of the patients through coils that are set beneath the floor and the bottom of the shoes. If the patients wear the special shoes, they will be able to move freely on the specially designed floor without an external battery. Direct current (DC)-DC power efficiency was measured in the experiments, and the results showed that it varies with relative positions between the shoe and the floor coils. The results suggested that three-layered floor coils would enable the system to meet the demand for providing the required power anywhere on the floor without intermission. DC-DC power efficiency could be kept over 60% under the practical condition. It can then be concluded that the proposed system has a potential to provide better quality of life for the patients using a TETS.

The role of friction in the measurement of slipperiness, Part 1: friction mechanisms and definition of test conditions

Friction has been widely used as a measure of slipperiness. However, controversies around friction measurements remain. The purposes of this paper are to summarize understanding about friction measurement related to slipperiness assessment of shoe and floor interface and to define test conditions based on biomechanical observations. In addition, friction mechanisms at shoe and floor interface on dry, liquid and solid contaminated, and on icy surfaces are discussed. It is concluded that static friction measurement, by the traditional use of a drag-type device, is only suitable for dry and clean surfaces, and dynamic and transition friction methods are needed to properly estimate the potential risk on contaminated surfaces. Furthermore, at least some of the conditions at the shoe/floor interface during actual slip accidents should be replicated as test conditions for friction measurements, such as sliding speed, contact pressure and normal force build-up rate.

The role of friction in the measurement of slipperiness, Part 2: survey of friction measurement devices

This paper seeks to address questions related to friction measurement such as how friction is related to human-centred assessment and actual slipping, and how repeatable friction measurements are. Commonly used devices for slipperiness measurement are surveyed and their characteristics compared with suggested test conditions from biomechanical observations summarized in Part 1. The issues of device validity, repeatability, reproducibility and usability are examined from the published literature. Friction assessment using the mechanical measurement devices described appears generally valid and reliable. However, the validity of most devices could be improved by bringing them within the range of human slipping conditions observed in biomechanical studies. Future studies should clearly describe the performance limitations of any device and its results and should consider whether the device conditions reflect these actual human slipping conditions. There is also a need for validation studies of more devices by walking experiments.

Human-centred approaches in slipperiness measurement

A number of human-centred methodologies--subjective, objective, and combined--are used for slipperiness measurement. They comprise a variety of approaches from biomechanically-oriented experiments to psychophysical tests and subjective evaluations. The objective of this paper is to review some of the research done in the field, including such topics as awareness and perception of slipperiness, postural and balance control, rating scales for balance, adaptation to slippery conditions, measurement of unexpected movements, kinematics of slipping, and protective movements during falling. The role of human factors in slips and falls will be discussed. Strengths and weaknesses of human-centred approaches in relation to mechanical slip test methodologies are considered. Current friction-based criteria and thresholds for walking without slipping are reviewed for a number of work tasks. These include activities such as walking on a level or an inclined surface, running, stopping and jumping, as well as stair ascent and descent, manual exertion (pushing and pulling, load carrying, lifting) and particular concerns of the elderly and mobility disabled persons. Some future directions for slipperiness measurement and research in the field of slips and falls are outlined. Human-centred approaches for slipperiness measurement do have many applications. First, they are utilized to develop research hypotheses and models to predict workplace risks caused by slipping. Second, they are important alternatives to apparatus-based friction measurements and are used to validate such methodologies. Third, they are used as practical tools for evaluating and monitoring slip resistance properties of footwear, anti-skid devices and floor surfaces.

The role of surface roughness in the measurement of slipperiness

Surface roughness has been shown to have substantial effects on the slip resistance between shoe heels and floor surfaces under various types of walking environments. This paper summarizes comprehensive views of the current understanding on the roles of surface roughness on the shoe and floor surfaces in the measurement of slipperiness and discusses promising directions for future research. Various techniques and instruments for surface roughness measurements and related roughness parameters are reviewed in depth. It is suggested that a stylus-type profilometer and a laser scanning confocal microscope are the preferred instruments for surface roughness measurements in the field and laboratory, respectively. The need for developing enhanced methods for reliably characterizing the slip resistance properties is highlighted. This could be based on the principal understanding of the nature of shoe and floor interface and surface analysis techniques for characterizing both surfaces of shoe and floor. Therefore, surface roughness on both shoe and floor surfaces should be measured and combined to arrive at the final assessment of slipperiness. While controversies around the friction measurement for slipperiness assessment still remain, surface roughness measurement may provide an objective alternative to overcoming the limitations of friction measurements.

Ergonomics considerations in the design and use of single disc floor cleaning machines

This study investigated ergonomics issues connected with the use of single-disc floor cleaning machines (buffers/polishers). Methods included interview/questionnaire surveys of users and other groups (maintenance personnel, purchasing managers, manufacturer representatives), along with video analysis. A notable proportion of users (56%) reported discomfort from machine use, mostly musculoskeletal in origin. Main locations were hand (39%), shoulder (19%), wrist (7%), lower back (7%) and arm (6%). Deficiencies were identified with the design and configuration of the handle/operating-switch. Problems were also found arising from the trailing power cable, along with manual handling implications due to machine size and weight. It is concluded there is scope to improve on current designs.