Effect of foot-floor friction on the external moment about the body center of mass during shuffling gait: a pilot study.

Herein, we investigated the effect of friction between foot sole and floor on the external forward moment about the body center of mass (COM) in normal and shuffling gaits. Five young male adults walked with normal and shuffling gaits, under low- and high-friction surface conditions. The maximum external forward moment about the COM (MEFM-COM) in a normal gait appeared approximately at initial foot contact and was unaffected by floor condition. However, MEFM-COM in a shuffling gait under high-friction conditions exceeded that under low-friction conditions (p < 0.001). Therein, MEFM-COM increased with an increasing utilized coefficient of friction at initial foot contact; this effect was weaker during a normal gait. These findings indicate that increased friction between foot sole and floor might increase tripping risk during a shuffling gait, even in the absence of discrete physical obstacles.

Chondronecrosis with osteomyelitis in broilers: further defining lameness-inducing models with wire or litter flooring to evaluate protection with organic trace minerals.

The feed additive Availa-ZMC was investigated for the ability to reduce lameness in broilers using 2 alternative models for inducing lameness. The mixture of organic trace minerals was effective in reducing lameness by 20% in the wire flooring model and 25% in the litter flooring model with the bacterial challenge. Lameness in both models is overwhelmingly attributable to bacterial chondronecrosis with osteomyelitis. The reduction in lameness was associated, at least in part, with enhanced intestinal barrier integrity mediated by elevated expression of tight junction proteins and stimulation of bactericidal killing of adherent peripheral blood monocytes obtained from the birds treated with Availa-ZMC. Lameness is a major animal welfare concern in broiler production. The wire flooring model and litter flooring model with the bacterial challenge are effective models for evaluation of management strategies for mitigating infectious causes of lameness.

Flock-level risk factors for outbreaks of infectious arthritis in lambs, Norway 2018.

BACKGROUND: Outbreaks of infectious arthritis in young lambs associated with Streptococcus dysgalactiae subspecies dysgalactiae (SDSD) lead to reduced animal welfare, increased use of antibiotics and economic losses for sheep farmers. Understanding risk factors is essential when developing strategies to prevent such outbreaks. This questionnaire-based cross-sectional study classified sheep flocks of respondents as cases or controls. Flock-level risk factors for outbreaks of infectious arthritis were assessed using a multivariable logistic regression model. RESULTS: Eighty-four of 1498 respondents (5.6%) experienced an outbreak of infectious arthritis in their flock in 2018, the year of study. Factors associated with a higher risk of outbreak were larger flock size (OR 1.3, 95% CI 1.1-1.4, per 100 lambs), plastic mesh flooring in the lambing pen (OR 3.0, 95% CI 1.7-5.3) and a lambing percentage greater than 200 (OR 2.0, 95% CI 1.1-3.5). Flocks where farmers observed infections around the ear tags of lambs also had an increased risk of outbreak (OR 2.6, 95% CI 1.6-4.3). CONCLUSIONS: The risk factors identified in this study are characteristic of modern and intensively managed sheep farms in Norway. A distinguishing feature of Norwegian sheep farming is winter housing and indoor lambing. One might expect that this in itself is a risk factor because of high stocking densities during lambing. However, outbreaks of infectious arthritis in young lambs are reported by the industry to be a more recent phenomenon. The current study indicates that intensification of indoor management systems with larger flocks and higher production per ewe may predispose to outbreaks. The results provide a basis for further studies on transmission dynamics of SDSD in sheep flocks with indoor lambing.

A risk assessment of health, production, and resource occupancy for 4 laying hen strains across the lay cycle in a commercial-style aviary system.

Different strains of commercial laying hens have been molded by varying selection pressures, impacting their production, health, and behavior. Therefore, assumptions that all laying hen strains use the given resources within aviary systems similarly and maintain equal health and performance may be false. We investigated interactions among patterns of aviary resource use by 2 strains of white and 2 strains of brown laying hens (4 units per strain, 144 hens per unit) with daily egg production, location of egg laying, keel fractures, and footpad damage across the lay cycle. Hens' distribution among resources (litter, nest, wire floor, ledge, and perch) was recorded during light and dark periods at 28, 54, and 72 wk of age. Daily egg production and location were recorded, and 20% of hens per unit were randomly selected and assessed for keel bone damage, foot health, and plumage quality. Production and health risks associated with hens' resource use were assessed using multivariable regression. During the day, more brown hens occupied wire floors, while larger numbers of white hens were on perches and litter. More brown hens were on lower-tier wire floors in the dark, while more white hens occupied top tiers. Brown hens laid more eggs outside nests, showed lower incidence of keel fractures, and had better plumage quality than white hens. White hens had higher odds of keel fractures (4.2) than brown hens. Odds of keel fractures were 3.7 and 5.7 times higher at 54 and 72 wk than at 28 wk in all strains (P ≤ 0.05). Occupying the upper tier at night increased odds of keel fractures by 5.4 times. Occupying perches was associated with lower odds of foot lesions and poor plumage quality in all strains across the lay cycle (P ≤ 0.05). Finally, white hens were associated with lower odds of non-nest laying (0.76), whereas higher nest use by brown hens resulted in higher odds of non-nest egg laying (1.56) across the lay cycle (P ≤ 0.05). Distinct strain differences in resource use in an aviary were associated with different risks to hens' production, health, and welfare.

Indoor Microbiome and Antibiotic Resistance on Floor Surfaces: An Exploratory Study in Three Different Building Types.

Floor materials in indoor environments are known to be reservoirs of microbes. We focused on examining bacterial community composition, antibiotic resistance (AR) and microbial source tracking (MST) of fecal bacteria on the floor surfaces. Swab samples were collected from carpet and vinyl floors in three different buildings (medical, veterinary, and office buildings) from high and low traffic areas. Bacterial communities were determined with 16S rRNA sequencing, and AR (tetracycline (tetQ), sulfonamide, and carbapenem (KPC)) and MST (human-, canine-, avian-, and ruminant-specific fecal bacteria) were examined with quantitative polymerase chain reaction (PCR). The results show that Proteobacteria and Actinobacteria were the most abundant phyla. Traffic level significantly affected the number of operational taxonomic units. Traffic level was a key factor for distinctive bacterial community in the medical center. Targeted ARGs were detected from all buildings and tetQ concentration was related with traffic level, and KPC was only detected from the medical center. Most of the floor surfaces showed the presence of dog-specific fecal bacteria (83%) followed by bird-specific fecal bacteria (75%). The results suggest that traffic levels affected the bacterial levels and fecal contamination is prevalent on the floor surfaces. This is the first study that reports KPC presence on the floor surfaces.

A survey of straw use and tail biting in Swedish pig farms rearing undocked pigs.

BACKGROUND: Tail biting is a common problem in intensive pig farming, affecting both welfare and production. Although routine tail docking is banned within the EU, it remains a common practice to prevent tail biting. Straw as environmental enrichment has been proposed as an alternative to tail docking, but its effectiveness against tail biting and function in manure handling systems have to be considered. The aim of the study was to survey how pigs with intact tails are raised and how tail biting is handled in Sweden, where tail docking is banned through national legislation. The study emphasises straw usage and its association with tail biting pigs and problems in the manure handling system. The expectation is that this information could be conveyed to the rest of the EU to reduce the need for tail docking. RESULTS: In a telephone survey of randomly selected Swedish pig farmers (46 nursery and 43 finishing pig units) with at least 50 sows or 300 finishing places, it was found that straw was used by 98% of the farmers. The median daily straw ration provided was 29 g/pig for nursery and 50 g/pig for finishing pigs in systems with partly slatted flooring. The reported prevalence of tail biting was 1.6% at slaughter. The majority of farmers reported that they never had manure handling problems caused by straw (56% of nursery units and 81% of finishing pig units). A proportion of farmers (37%) also provided with additional material apart from straw on some occasions, which may have affected tail biting prevalence and manure handling problems. CONCLUSIONS: Swedish farmers rear undocked pigs without large problems with tail biting. Straw is the main manipulable material used, and additional manipulable material is used to various extents. The low incidence of straw obstructing the manure handling systems implies that it is indeed possible to use straw in partly slatted flooring systems, reducing the need for tail docking. The impact of using additional manipulable material is unknown and requires more investigation to separate the impact of such material from the impact of straw.

Floor space covered by broiler chickens kept at stocking densities according to Council Directive 2007/43/EC.

It is controversially discussed whether the stocking densities set by the EU Directive 2007/43/EC allow a species-appropriate housing of broiler chickens. To calculate the exact area broilers occupy due to their physical size and shape, planimetric measurements using a colour-contrast method were carried out. In total, 1949 photographs of standing and 1482 of squatting chickens, taken from a top view, were analysed. A computer program counted the pixels representing the previously weighed animal in the photograph and calculated the animal area. The average area covered by chickens with 400 g live weight was 116.64±13.12 cm(2) in a standing and 138.61±12.92 cm(2) in a squatting position. These areas increased linearly as a function of live weight to 452.57±58.89 cm(2) (R(2)=0.90 standing) and 513.54±42.70 cm(2) (R(2)=0.82 squatting) at the end of the study (3200 g live weight). Squatting chickens occupied more space compared with a standing position in most of the tested weight classes (P<0.05). Depending on target weights, stocking densities and body positions, broilers occupied 48.5-77.7 per cent of 1 m(2) Thus, from a physical point of view, simultaneous resting is possible at any stocking density provided by the EU Directive and at common target weights.

Urinary pyrethroid and chlorpyrifos metabolite concentrations in Northern California families and their relationship to indoor residential insecticide levels, part of the Study of Use of Products and Exposure Related Behavior (SUPERB).

Since the 2001 U.S. federally mandated phase-out of residential uses of organophosphates (OPs), use of and potential for human exposure to pyrethroids in the indoor residential environment has increased. We report concentrations of common pyrethroids, pyrethroid metabolites, and chlorpyrifos in floor wipes, and urinary concentrations of pyrethroid metabolites and 3,5,6-trichloro-2-pyridinol (TCPy) in samples collected in 2007-2009 from 90 northern California families as part of the Study of Use of Products and Exposure Related Behavior (SUPERB). Correlation and regression analyses examined associations between floor wipe and urine sample concentrations. The most frequently detected urinary metabolites were TCPy (64.7%, median concentration of 1.47 ng/mL) and 3-phenoxybenzoic acid (3PBA) (62.4%, 0.79 ng/mL). Compared to the National Health and Nutrition Examination Survey (NHANES) 2001-2002 general U.S. population, this population had substantially higher pyrethroid metabolite and lower TCPy urinary concentrations. This may be related to the increased residential use of pyrethroids after the phase-out of OPs. Chlorpyrifos (98.7%), cis- and trans-permethrin (97.5%), bifenthrin (59.3%), and 3PBA (98.7%) were frequently detected in the floor wipes. Floor wipe concentrations for pyrethroid insecticides were found to be significant predictors of child creatinine-adjusted urinary metabolite concentrations (log-log regression coefficients ranging from 0.26 to 0.29; p < 0.05) suggesting that indoor residential exposure to pyrethroid insecticides is an important exposure route for children.

Associations of phthalate concentrations in floor dust and multi-surface dust with the interior materials in Japanese dwellings.

Phthalates are widely used as plasticizers in numerous products. However, there has been some concern about the various effects they may have on human health. Thus, household phthalate levels are an important public health issue. While many studies have assessed phthalate levels in house dust, the association of these levels with building characteristics has scarcely been examined. The present study investigated phthalate levels in house dust samples collected from the living areas of homes, and examined associations between these phthalate levels and the interior materials. Dust was collected from two portions of the living area: floor dust from the entire floor surface, and multi-surface dust from objects more than 35 cm above the floor. The levels of seven phthalates were measured using gas chromatography/mass spectrometry in selective ion monitoring mode. Phthalate levels were higher in multi-surface dust than in floor dust. Among floor dust samples, those from dwellings with compressed wooden flooring had significantly higher levels of di-iso-butyl phthalate compared to those with other floor materials, while polyvinyl chloride (PVC) flooring was associated with higher di-2-ethylhexyl phthalate (DEHP) levels. Among multi-surface dust samples, higher levels of DEHP and di-iso-nonyl phthalate (DINP) were found in samples from homes with PVC wallpaper than without. The number of PVC interior materials was significantly positively correlated with the levels of DEHP and DINP in multi-surface dust. The phthalate levels in multi-surface dust were associated with the interior surface materials, and those in floor dust were directly related to the flooring materials. Our findings show that when using house dust as an exposure assessment, it is very important to note where the samples were collected from. The present report provides useful information about the association between phthalates and dust inside dwellings, which will assist with establishing public health provisions.

The effect of field condition and shoe type on lower extremity injuries in American Football.

BACKGROUND/AIM: Considerable improvement has been made in football field surfaces and types of shoe, yet relatively few epidemiological studies have investigated their roles in the risk of football injuries. This study examined the effects of field surface, surface condition and shoe type on the likelihood of lower extremity football injuries. METHODS: Deidentified data from 188 players from one division I university football team during the 2007-2010 seasons were analysed. Lower extremity injury rate and rate ratio, along with 95% confidence limits, were calculated by football activity, playing surface condition and shoe type. RESULTS: A total of 130 lower extremity injuries were sustained, with an overall lower extremity injury rate of 33.5/10 000 athlete-sessions. The lower extremity injury rate was 2.61 times higher when the surface condition was abnormal compared with when the surface condition was normal. During games, the risk for lower extremity injury was 3.34 times higher (95% CI 1.70 to 6.56) on artificial turf compared with natural grass. However, this trend was not statistically significant in practice sessions. Furthermore, neither the number of shoe cleats nor the height of the shoe top was statistically associated with risk of lower extremity injuries. CONCLUSIONS: Football players who played on artificial turf or when the surface condition was abnormal were susceptible to lower extremity injuries. Evidence from this study suggests that further research into playing surfaces and shoe types may provide fruitful opportunities to reduce injuries to collegiate football players.

The Nordic Football Injury Audit: higher injury rates for professional football clubs with third-generation artificial turf at their home venue.

BACKGROUND: Previously, no difference in acute injury rate has been found when playing football on artificial turf (AT) compared with natural grass (NG). AIM: To compare acute injury rates in professional football played on AT and NG at the individual player level; and to compare, at club level, acute and overuse injury rates between clubs that have AT at their home venue (AT clubs) and clubs that have NG (NG clubs). METHODS: 32 clubs (AT, n=11; NG, n=21) in the male Swedish and Norwegian premier leagues were followed prospectively during the 2010 and 2011 seasons. Injury rate was expressed as the number of time loss injuries/1000 h and compared with rate ratio (RR) and 99% CI. RESULTS: No statistically significant differences were found in acute injury rates on AT compared with NG during match play (RR 0.98, 99% CI 0.79 to 1.22) or training (RR 1.14, 99% CI 0.86 to 1.50) when analysing at the individual player level. When analysing at the club level, however, AT clubs had a significantly higher acute training injury rate (RR 1.31, 99% CI 1.04 to 1.63) and overuse injury rate (RR 1.38, 99% CI 1.14 to 1.65) compared with NG clubs. CONCLUSIONS: At the individual player level, no significant differences were found in acute injury rates when playing on AT compared with NG. However, clubs with AT at their home venue had higher rates of acute training injuries and overuse injuries compared with clubs that played home matches on NG.

Biomechanics and injury risk assessment of falls onto protective floor mats.

This study investigated the biomechanics of simulated sideways falls from various bed heights onto two types of protective floor mats. This article presents biomechanical injury criteria for evaluating the probability of sustaining injuries to the head, thorax, and pelvis. A side-impact dummy was raised to drop heights of 45.7 cm, 61.0 cm, and 76.2 cm and released. Two types of protective floor mats were evaluated and compared with impacts experienced on an unpadded, rigid floor. Results of the study demonstrated a high risk (> 50%) for serious head injury for falls onto an unpadded, rigid floor at 61.0-cm and 76.2-cm drop heights. Falls onto floor mats demonstrated significant reductions in injury risk to the head and pelvis for all drop heights. Thoracic injury risk was significantly reduced for all but the highest drop height.

Non-accidental collision followed by dental trauma: associated factors.

The aim of the present cross-sectional survey was to assess factors associated with non-accidental collision followed by dental trauma among adolescents in the city of Diamantina, Brazil. A total of 387 students from 12 to 15 years of age (mean = 14 SD = 0.9) were randomly selected. The study was carried out in two stages. Firstly, data were collected through dental examinations of permanent incisors. Secondly, a thorough interview was held with 85 adolescents who exhibited dental trauma in the dental examinations. The interview consisted of a detailed description of the incident and physical environment in which it occurred. Descriptive analysis and the chi-square test (P < 0.05) were performed. The prevalence of dental injury was 22% (n = 85). Dental trauma was more prevalent in boys (P = 0.001) and individuals with overjet >3 mm (P = 0.007) and inadequate lip coverage (P = 0.013). Analysis of the event revealed that 22.3% of the cases of dental trauma occurred because of non-accidental collision. Non-accidental collision followed by injury occurred mainly at school (P < 0.001) and in an environment with a concrete, tiled or ceramic floor (P = 0.001). No statistically significant associations were found between non-accidental collision and gender, age or mother's schooling. It was concluded that the non-accidental collisions happened especially at school and in indoor environments with a concrete, tiled or ceramic floor.

A prospective study of floor surface, shoes, floor cleaning and slipping in US limited-service restaurant workers.

OBJECTIVES: Slips and falls are a leading cause of injury at work. Few studies, however, have systematically examined risk factors of slipping outside the laboratory environment. This study examined the association between floor surface characteristics, slip-resistant shoes, floor cleaning frequency and the risk of slipping in limited-service restaurant workers. METHODS: 475 workers from 36 limited-service restaurants from three major chains in six states in the USA were recruited to participate in a prospective cohort study of workplace slipping. Kitchen floor surface roughness and coefficient of friction (COF) were measured in eight working areas and then averaged within each restaurant. The use of slip-resistant shoes was determined by examining the participant's shoes and noting the presence of a 'slip-resistant' marking on the sole. Restaurant managers reported the frequency of daily kitchen floor cleaning. Participants reported their slip experience and work hours weekly for up to 12 weeks. The survey materials were made available in three languages: English, Spanish and Portuguese. The associations between rate of slipping and risk factors were assessed using a multivariable negative binomial generalised estimating equation model. RESULTS: The mean of individual slipping rate varied among the restaurants from 0.02 to 2.49 slips per 40 work hours. After adjusting for age, gender, BMI, education, primary language, job tenure and restaurant chain, the use of slip-resistant shoes was associated with a 54% reduction in the reported rate of slipping (95% CI 37% to 64%), and the rate of slipping decreased by 21% (95% CI 5% to 34%) for each 0.1 increase in the mean kitchen COF. Increasing floor cleaning frequency was significantly associated with a decreasing rate of slipping when considered in isolation but not after statistical adjustment for other factors. CONCLUSION: These results provide support for the use of slip-resistant shoes and measures to increase COF as preventive interventions to reduce slips, falls and injuries.

Indoor pesticide application practices and levels in homes of Bangkok Metropolitan Region.

This study investigated the indoor application practices of pesticides in different homes located in urban, suburban, and rural areas of the Bangkok Metropolitan Region (BMR). A multi-stage stratified-judgmental sampling was applied to select 280 representative households in BMR for an in-depth questionnaire survey. We found about 71% of these households having mosquitoes as their main indoor nuisance. An inventory on the types and active ingredients was obtained through a shop-shelf survey. Among 22 available commercial products, 12 different active ingredients were observed with the pyrethroid containing pesticides are the most common. The stepwise regression analysis was conducted to reveal the statistical association between indoor levels of total pyrethriods (in the air and on the floor surface of homes) and the household application practices such as the overlap time period since the last application, application and storage locations, and frequency of applications, for instances.

Household characteristics and allergen and endotoxin levels in Aleppo, Syrian Arab Republic.

Few data are available from Eastern Mediterranean countries about levels of domestic allergens and endotoxins. Dust samples were collected from mattresses and floors of 457 homes in the Syrian city of Aleppo and analysed for antigens and endotoxins. The most important predictors for detectable levels of house-dust mite allergen Der p 1 were Arabic-style houses (OR 3.21) and newer houses (OR 1.56). In homes without cats, rubber mattresses were associated with detectable cat allergen Fel d 1 in mattress dust (OR 1.6). Cockroach allergen Bla g 2 was significantly more likely to be detected in houses over 20 years old than newer houses. Endotoxin levels were significantly higher in wool/cotton mattresses and older houses.

Evaluation of guardrail systems for preventing falls through roof and floor holes.

INTRODUCTION: Fall-related occupational injuries and fatalities are serious problems in the U.S. construction industry, especially incidents related to unguarded holes. The National Institute for Occupational Safety and Health, Division of Safety Research, Morgantown, WV conducted a project to evaluate the effectiveness of guardrail systems to prevent falls through roof and floor holes. METHODS: Two commercial edge-protection products were evaluated when used as perimeter guarding around a roof hole. Installations of the commercial products were compared to job-built guardrails constructed of 2('')x4('') construction-grade lumber. Occupational Safety and Health Administration (OSHA) regulations require that "a force of at least 200 pounds" must be supported by the top rail of a guardrail system "in any outward or downward direction at any point along the top edge." A laboratory testing system was developed to evaluate this requirement. A dynamic 200-lb force was generated against the top rail using a weighted manikin mounted on a hinged steel frame. Nine construction workers, who served as test subjects, each built five different guardrail configurations. RESULTS: All 45 configurations met the 200-lb OSHA requirement. Installation time for one commercial product was 32% quicker than the job-built configuration (25.6 min vs. 37.9 min). IMPACT ON INDUSTRY: This study: (a) indicates that the two edge-protection products can be used as perimeter guarding; (b) highlights the importance of using proper materials and fasteners to construct guardrails to protect workers from falling into unguarded roof and floor holes; and (c) discusses an overall-strength-testing methodology that can be used by fall-protection researchers.

Relationship between home hazards and falling among community-dwelling seniors using home-care services.

BACKGROUND: Evidence linking home hazards to falls has not been well established. The evidence-based approach to fall-risk assessment in longitudinal studies becomes difficult because of exposures that change during follow-up. We conducted a cohort study to determine the prevalence of hazards and to resolve whether they are linked to the risk of falls among 959 seniors receiving home-care services. METHODS: A home hazards assessment was completed at entry and every six months thereafter using a standardized form. The adjusted (for a number of confounding factors) relationship between home hazards and falls was estimated using a survival model taking into account updated time-varying exposures and multiple events. Falls leading to a medical consultation were examined as a secondary outcome, hypothesized as a measure of severity. FINDINGS: Home environmental hazards were found in 91% of homes, with a mean of 3.3 risks per individual. The bathroom was the most common place for hazards. The presence of hazards was significantly associated with all falls and fall-related medical consultations, and showed relatively constant effects from one fall to another. IMPLICATIONS: The current study is innovative in its approach and useful in its contribution to the understanding of the interaction between home environmental hazards and falls. Our results indicate that inattention to changes in exposure masks the statistical association between home hazards and falls. Each environmental hazard identified in the home increases the risk of falling by about 19%. These findings support the positive findings of trials that demonstrate the effectiveness of this home hazard reduction program, particularly for at-risk people.

Consumer products and activities associated with dental injuries to children treated in United States emergency departments, 1990-2003.

OBJECTIVE: Describe the association of consumer products and activities with dental injuries among children 0-17 years of age treated in United States emergency departments. DESIGN: A retrospective analysis of data from the National Electronic Injury Surveillance System, 1990-2003. RESULTS: There was an average of 22 000 dental injuries annually among children <18 years of age during the study period, representing an average annual rate of 31.6 dental injuries per 100 000 population. Children with primary dentition (<7 years) sustained over half of the dental injuries recorded, and products/activities associated with home structures/furniture were the leading contributors. Floors, steps, tables, and beds were the consumer products within the home most associated with dental injuries. Outdoor recreational products/activities were associated with the largest number of dental injuries among children with mixed dentition (7-12 years); almost half of these were associated with the bicycle, which was the consumer product associated with the largest number of dental injuries. Among children with permanent teeth (13- to 17-year olds), sports-related products/activities were associated with the highest number of dental injuries. Of all sports, baseball and basketball were associated with the largest number of dental injuries. CONCLUSION: To our knowledge, this is the first study to evaluate dental injuries among children using a national sample. We identified the leading consumer products/activities associated with dental injuries to children with primary, mixed, and permanent dentition. Knowledge of these consumer products/activities allows for more focused and effective prevention strategies.

Comfort zone-design free stalls: do they influence the stall use behavior of lame cows?

The behavior of 59 cows in 4 herds, each with Comfort Zone-design free stalls with dimensions suitable for 700-kg, mature Holstein dairy cows, was filmed for a 48-h period. Comparison was made between nonlame, slightly lame, and moderately lame cows on either rubber-crumb-filled mattress stall surfaces bedded with a small amount of sawdust (2 herds) or a Pack Mat design, which consisted of a rubber-crumb-filled mattress pad installed 5 cm below a raised rear curb, bedded with 5 to 8 cm of sand bedding (2 herds). All other stall design components were similar. Despite adequate resting space and freedom to perform normal rising and lying movements, lame cows on mattresses stood in the stall for >2 h longer than nonlame cows. Although a significant increase in stall standing behavior was observed in lame cows on Pack Mat stalls, the mean (95% confidence interval) standing time in the stall was only 0.7 (0 to 3.0) h/d for nonlame cows and 1.6 (0 to 4.2) h/d for moderately lame cows, which was less than the 2.1 (0 to 4.4), 4.3 (1.6 to 6.9), and 4.9 (2.5 to 7.3) h/d spent standing in the stall for nonlame, slightly lame, and moderately lame cows on mattresses, respectively. This observation supports the hypothesis that it is the nature of the stall surface that dictates changes in stall standing behavior observed in lame cows, rather than other components of stall design. The finding that only 5 to 8 cm of sand over a mattress pad provides most of the benefits of deep sand-bedded stalls, along with other advantages related to stall maintenance and manure handling, gives farmers another useful housing alternative with which to improve cow comfort and well-being.