Article, Emergency Medicine

Lawn mower injuries presenting to the emergency department: 2005 to 2015

a b s t r a c t

Objective: The objective of this study was to describe recent trends in the epidemiology of lawn mower injuries presenting to the Emergency Department in the United States using nationally representative data for all ages. Methods: Data for this retrospective analysis were obtained from the U.S. Consumer Product Safety Commission’s National Electronic Injury surveillance System (NEISS), for the years 2005-2015. We queried the system using all product codes under “lawn mowers” in the NEISS Coding Manual. We examined body part injured, types of in- juries, gender and age distribution, and disposition.

Results: There were an estimated 934,394 lawn mower injuries treated in U.S. ED’s from 2005 to 2015, with an average of 84,944 injuries annually. The most commonly injured body parts were the hand/finger (22.3%), followed by the lower extremity (16.2%). The most common type of injury was laceration (23.1%), followed by sprain/strain (18.8%). The mean age of individuals injured was 46.5 years, and men were more than three times as likely to be injured as women. Patients presenting to the ED were far more likely to be discharged home after treatment (90.5%) than to be admitted (8.5%).

Conclusion: Lawn mowers continue to account for a large number of injuries every year in the United States. The incidence of lawn mower injuries showed no decrease during the period of 2005-2015. Preventative measures should take into account the epidemiology of these injuries.

(C) 2018



Mowing the lawn is a part of daily life in the United States. The U.S. Bureau of Labor Statistics found that in the year 2015, 9.8% of Americans engaged in “lawn and garden care”, with 12.1% of men and 7.7% of women performing these tasks [1]. Lawn mowers pose a partic- ular risk due to their relatively powerful engines and fast moving blades. However, the commonplace nature of these products may lead people to underestimate the threat posed by lawn mowers. This threat is not limited to the lawn mower users, but also includes bystanders that may be injured by flying debris [2-12].

It has been estimated that approximately 74,000 people with lawn

mower injuries (LMIs) present to Emergency Departments (ED) annually [3]. Although amputations and burns may be considered the prototypical lawn mower injuries, they represent the minority of lawn mower injuries in both pediatric and adult studies [2-5,13]. Previous studies have shown that other types of injuries, including lacerations and strains/sprains, are far more common injuries [2-5]. These injuries affect all age groups and

* Corresponding author.

E-mail address: [email protected] (T.R. Hartka).

special attention is often given to preventing Pediatric injuries [4,6-7,9- 12,14-18]. However, those between the ages of 40-70 years old appear to be at the highest risk of being injured while using lawn mowers [3,5,13].


There are a significant number of ED visits related to lawn mower in- juries every year, and previous work has shown a slight increase in inci- dence of these injuries over previous decades [3]. This may indicate that lawn mowers represent a line of products that have not made significant progress in the area of consumer safety. Several previous studies have uti- lized the National Electronic Injury Surveillance System to exam- ine lawn mower injuries. The most recent study presented data from 1990 to 2014 but included only pediatric patients (N18 years of age) [12]. The most recent studies presenting nationally representative data on adults examined the years from 1996 to 2004 and 2004-2007 [3,5]. There has been no published examination of national data regarding lawn mower injuries in patients older than 20 years of Age SInce 2007.

Goals of this investigation

The objective of this study was to examine recent trends in lawn mower injuries presenting to EDs in the United States for both children

0735-6757/(C) 2018

and adults, using data from NEISS for 2005-2015. Using this data, we aim to better tailor prevention measures that could reduce annual inci- dence of LMI.



Data were obtained from the NEISS database of the United States Consumer Product Safety Commission. The NEISS compiles data col- lected by a national probability sample of exactly 100 emergency de- partments throughout the U.S. and its territories. Cases are then weighted according to sample design, in order to produce national esti- mates for the number of ED visits represented by each case [19-20].

Inclusion criteria

Criteria for data selection included all LMI occurring between 2005 and 2015 in patients of all ages. The specific NEISS lawn mower product codes queried included: 1401 – Powered lawn mowers, 1402 – Manual push lawn mowers, 1405 – “Garden tractors”, 1422 – “Riding power lawn mower”, 1439 – “Lawn mowers, not specified”, and 1448 – “Rotary power lawn mowers (walk-behind)”.


Lawn mower types were categorized into “walk-behind,” “ride-on,” and “other” (unspecified) groups, containing codes 1402 and 1448, 1405 and 1422, and 1401 and 1439, respectively. Date of visit, age, sex, race, diagnosis, body part affected, and ED disposition were among the many variables collected per case. Diagnosis and body part were re-coded into specific subgroups in order to view trends during analysis.

Body parts were grouped according to body region. “Head and neck” included the scalp, parietal and occipital regions, neck, and the ears, while “face and eyeball” collectively included face, eyeball, and mouth. “Lower trunk” included the lumbar vertebrae and pubic region. “Upper extremity” includes shoulder, upper arm, elbow, lower arm, and wrist. “Lower extremity” includes upper leg, knee, lower leg, and ankle. “Hand/finger” and “foot/toe” were grouped separately. The re- maining body part codes were labeled as “other,” and included cases where percentages of the entire body were affected or the body part was not specified in the record.

Certain diagnoses were grouped according to the type of injury. Common diagnoses were not combined with other codes. These com- mon diagnoses included “fracture,” “amputation,” “sprain/strain,” and “projectile (foreign body)” injury. “Burns” included electrical, scalding, chemical, and thermal burns. “soft tissue injuries” included contusions, abrasions, crushing injuries, and hematoma. Injuries to the skin were collectively labeled “laceration,” and contained lacerations, punctures, and avulsion.


The NEISS data were compiled and analyzed utilizing IBM SPSS Sta- tistics software (version 24). Univariate analyses were computed using descriptive statistics procedures, while cross-tabulations were used for bivariate analyses.


There were an estimated 934,394 LMIs presenting to U.S. emergency departments from 2005 to 2015 (Table 1). During this 11-year period, there were approximately 85,000 injuries each year, on average. Fig. 1 shows the estimated year incidence of LMIs presenting the ED. The esti- mated incidence varied up to 7.38% between consecutive years (2010

Table 1 Incidence and demographic characteristics of LMIs based on national estimates from NEISS over an 11-year period from 2005 to 2015.

Total incidence from 2005 to 2015 934,394

Annual incidence 84,945

Population-based annual incidencea 27.5

Median age (Q1, Q3) 47 (33,60)

Gender [%] (male) 77.1

Race [%] (white/black/other/unknown) 65.5/6.2/3.3/25.2

LM type [%]

Walk-behind 8.9

Ride-on 18.8

Not specified 72.3

ED disposition [%]

Discharged 90.5

Admitted/transferred 8.5

Fatalities 0.3

LWBS/unknown 0.7

a Number of injuries per 100,000 people, based on the 2010 U.S. Census. The overall population in 2010 was 308,745,538. LWBS – Left without being seen.

and 2011) during the study period. The highest number of injuries oc- curred in 2010 (91,332 LMIs) and the lowest was in 2007 (80,917 LMIs). However, there was no overall trend towards increasing or de- creasing rates of injury during the study period. Most of these injuries occurred in the summer months, with May having the highest number and February having the least number of injuries (Fig. 2).

The incidence of LMIs peaked in middle age. Fig. 3 shows the distri- bution of LMIs by age of the injured person. The age ranges of 45-48 and 49-52 years had the highest rates of LMIs, with a mean age of 46.5 years. Younger children (0-4 years old) were more likely to be injured than older children. After age 12, the number of injuries increases with age until a peak in the late 40s. Men accounted for a majority of the cases, 77.1%, while women only accounted for 22.9%. With respect to race, Whites were the group most affected (65.3%), followed by Blacks (6.2%) and Asians (0.2%). (Table 1).

Laceration was the most common injury (23.1%), followed by sprain/strain (18.8%) and soft tissue injury (14.8%). Table 2 lists the most common injury diagnoses and body parts affected by LMIs. Burns (3.2%) and amputations (2.9%) were among the least common. Insect bites while operating the mower accounted for an estimated 17,859 cases (1.9%) and concussions accounted for an estimated 3360 cases (0.4%). The hand/finger was the most commonly injured body part (22.3%), followed by the lower extremity (which excludes the feet and toes) (16.2%), and the lower trunk (13.8%). The head/neck was the least commonly injured (5.4%), yet this body region still accounted for an estimated 50,838 cases in this 11-year span. Among patient with hand injuries lacerations, fractures, and amputations were the most common injuries (Table 3).

The large majority of patients with LMIs (90.5%) were discharged from the ED after being examined and/or treated (Table 4) There were, however, 79,786 cases (8.5%) in which the patient was admitted

Fig. 1. Annual incidence of LMIs in the U.S. from 2005 to 2015.

Table 2

Frequency distribution of diagnoses and body parts affected for LMIs pre- senting to emergency departments during an 11-year period from 2005 to 2015.


Body part

Fig. 2. Distribution of cases by month from 2005 to 2015.

Hand or finger


Lower extremity


Lower trunk


Face or eye


Upper extremity


Upper trunk


Foot or toe


Head or neck


Other/not stated



Laceration Sprain or strain



Soft tissue injurya


Fracture or dislocation




Projectile (foreign body)








Chest pain


Back pain


Bee/insect bite/sting


or transferred to another facility. Patients who suffered from amputa- tions were the most likely to be admitted for their injuries. Specifically, 34% of those with amputations were admitted, compared to 23.3% and 20.6% of concussion and fracture cases, respectively. Patients with sprain/strain injuries were the least likely to be admitted (0.5%). Addi- tionally, from 2005 to 2015, there were an estimated 2435 deaths asso- ciated with LMIs, but these were relatively uncommon (0.3%). This included patients who were dead-on-arrival and those who died in the emergency department. This number does not include those who died after transfer or after admission to the hospital.


There are a number of limitations to this study due the nature of an- alyzing sampled data [21]. First, the NEISS database reports the number of emergency department visits, not the actual number of patients in- jured. Therefore, the actual number of people who suffer Lawn mower-related injuries may differ. Patients who did not seek treatment and those who presented to urgent care or Primary care clinics were not captured in the NEISS data. Alternatively, patients presenting for multi- ple ED visits due to a single injury could be captured as two separate in- juries. It is likely that the incidence of LMIs reported in this study underestimates the actual number of LMIs occurring in the U.S. annually.

Another limitation is the potential for error during data collection and coding. NEISS is a well-coordinated system of hospitals that collect data on injuries from consumer products. However, this system relies on information received from patients and documented in the medical chart. Coders review the medical record to transcribe this information into NEISS codes (i.e. injury diagnosis, lawn mower type). Errors can be introduced by inaccurate or incomplete information given by patient or recorded medical staff.

Finally, the NEISS includes all potential injuries that occurred while using a given product. There are injury narratives such as, “Walking in the basement barefooted and accidentally stubbed toe against wheel

Fig. 3. Age distribution of total LMIs between 2005 and 2015.

a Soft tissue injury excludes sprain and strain.

b Most common “other” diagnoses given in terms of % overall.

of lawn mower.” While this injury represents an injury related to a lawn mower, this could have easily been any other object. In such cases are there is no quality intrinsic to the lawn mower that led to this injury and likely no way to improve the design of the lawn mower to avoid these injuries. These cases may be inappropriate to have included as LMIs. Unfortunately, there is no readily available method of removing these cases from the analysis other than reviewing each case individually and these cases represent a small minority of LMIs, so they are included in our analysis.


Lawn mowers continue to contribute to a significant number of ED visits in the United States every year. Our analysis of the NEISS database shows that the annual estimates of lawn mower related injuries (LMIs) showed no appreciable decrease in the period between the years of 2005 and 2015. This is despite increasing safety awareness by several organizations including the Consumer Product Safety Commission and the American Academy of Pediatrics. Although there is often a focus on pediatrics, these injuries affect all age groups and actually peak dur- ing middle age. Our data indicates that there is continued opportunity to substantially decrease LMIs.

The exposure regarding lawn mower use in the general population is difficult to determine. In 2010, the U.S. Census Bureau estimated that there were 152 million males and 157 million females living in the United States [22]. In the same year, the Bureau of Labor Statistics found that 12.3% of males and 7.6% of females engaged in lawn care. This corresponds to 19 million males and 12 million females involved in lawn care, although this does not address the specific activity of using a lawn mower. In accordance with previous studies, we found that males accounted for far more injuries than females [2-5,12-13]. It is not known if the exposure changed during the study period. It is inter- esting that the lowest reported yearly incidence of LMIs was in year 2007. This corresponds to a nadir in the U.S. economy associated with the Great Recession [23]. The decrease in reported LMIs could represent a decrease in lawn mower use or a decrease in those seeking treatment for these injuries. However, regardless of the relative rate of injury from lawn mowers, this remains an area for improvement in public safety.

Table 3

Distribution of types of injury based on body region over an 11-year period from 2005 to 2015. The two highest percentages in each body region are shown in bold.

Body region




Soft tissue injury


























Upper trunk










Lower trunk










Upper extremity




















Lower extremity




















other/not stated










There are several challenges to impacting lawn mower safety. One of the most significant challenges is the heterogeneous nature of these in- juries. The mechanisms of injury varied widely. Examples of mecha- nisms of LMIs include extremity amputations from moving blades, burns from hot engine components, and projectiles ejected from the lawn mower. The body region of injury likewise showed significant var- iation. Our analysis of the data showed that the upper trunk was a com- monly injured body region, however this accounted for 8.7% of injuries. The varied mechanisms and location of injury make it difficult to uni- formly improve lawn mower safety. However, over one-third injuries involved the hands and upper extremities, with the majority injuries being lacerations, fractures, and amputations. Interventions aimed at protecting the hands and upper extremities have the potential to make a significant impact.

There are additional opportunities to improve safety. A significant number of injuries are due to projectiles accelerated by the lawn mower’s cutting or drive mechanisms. Objects that are propelled by the lawn mower blade can reach speeds similar to those of bullets shot from a gun [7,11,24]. There are several Pediatric case reports that describe penetrating Thoracic trauma due to projectiles [8,11,14-15]. In these cases there may be very little external evidence of injury even in the setting of severe internal organ damage [8,11,14-15]. As with most LMI studies, many authors have focused on the dangers to chil- dren, but this shows that adults are also affected by these types of inju- ries. To prevent injury, users should ensure that debris is cleared from the yard, there are no bystanders in the yard, and the guard/shield is on the mower properly.

Table 4

Bivariate analysis of ED disposition distribution based on body part injured and diagnosis.

ED disposition

Discharged [%] Hospitalized [%]

Body parta

Hand or finger



Lower extremity



Lower trunk



Face or eye



Upper extremity



Upper trunk



Foot or toe



Head or neck



Other/not stated







Sprain or strain



Soft tissue injuryb



Fracture or dislocation






Projectile (foreign body)









Other/not stated



a Row percentages do not total to 100 because the disposition category “other/un- known” was not included.

b Soft tissue injury excludes sprain and strain.

eye protection appears to also be an important safety intervention. This has significant overlap with projectile safety since most of the eye injuries were due to projectiles. In two national pediatric studies, the face (including the eyeballs) was the third most commonly injured body region. In fact, the proportion of injuries affecting the eyeball/ face increased in patients b21 years of age from 1990 to 2013 [2,4]. Our analysis showed that the face/eyeball was the fourth most com- monly injured body region in all ages from 2005 to 2015. This could be partly due to the fact that patients with facial injuries may be more likely to present to the ED, and thus be captured in the NEISS database, than patients with injuries affecting the foot, for example. Nonetheless, this demonstrates that these injuries remain a significant issue and that they affect all age groups. Like protecting against projectile injuries, users should be sure to minimize debris in the cutting area and be vigi- lant of potential bystanders. Additionally, lawn mower users should wear eye protection at all times.

Cardiovascular health may play an unexpectedly significant role in LMIs. The narratives of a sample of these cases showed that many of these patients developed exertional chest pain while using the mower. When cases were analyzed for narratives that contained “chest pain,” we found that these accounted for 2.1% of all injuries, or a total of 19,533 estimated cases. Another national study examined the mechanisms by which these upper trunk injuries occurred, and found that physical stress was the leading mechanism for all patients older than 15 years [3]. It is important to remember that mowing the lawn often involves substantial physical exertion and may represent the most significant exertion in which a person engages. The cardiovas- cular health of the individual should be considered when assessing lawn mower safety.

The group of people most likely to be injured from lawn mowers are males from 40 to 60 years of age [5]. Interventions should be aimed at this demographic, at least in part, in order to be maximally effective. Changing behavior in this group presents unique challenges. Patients may not visit their primary care physician frequently in this age group. They may also have significant comorbidities, requiring in- creased vigilance regarding lawn mower safety [1,13]. Due to these ob- stacles, it may take non-traditional interventions to change behavior in this demographic.

Lawn safety is an area that requires further research. Accurately identifying the mechanism of injuries is key to prevention. The NEISS database provides a wealth of information that would not be available otherwise. However, our analysis found the large majority of cases (representing an estimated 670,000 LMIs) did not specify basic informa- tion, such as whether the mower was ride-on or walk-behind. Accu- rately capturing and analyzing this type of information would allow us to have a better understanding of the etiology of LMIs and steps for prevention.


Lawn mowers continue to account for a large number of injuries every year in the United States, especially in the population of males be- tween 40 and 60 years of age. The incidence of lawn mower injuries

showed no decrease during the period of 2005-2015. Given the varied nature of these injuries, multiple preventative strategies are likely nec- essary to improve lawn mower safety.

Meeting presentations


Grant or external funding


Author contributions

“TH developed the idea for this study and supervised the execution and manuscript writing. CH performed the background research and wrote the background and discussion sections. JM performed the statis- tical analysis and wrote the methods and results sections. All authors contributed substantially to revision of this manuscript. TH takes re- sponsibility of this paper as a whole.”


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