Nonfatal Incidents Involving Aerial Lifts and Ladders: Us Versus Them

Years ago, Isaac Newton said, “What goes up, will come down.” Arborists, other professional tree workers and amateurs all can go up to access tree canopies using aerial devices and ladders, but they may not come down the same way; it might be by a fall instead.

So, what is happening out there for nonfatal injuries from accessing tree canopies by ladders, scissor-lifts and other mobile, aerial-lift devices? Are different incidents occurring to the homeowners versus tree workers? That is the focus of this article, one in a continuing series titled “Us versus Them,” where we contrast the operational incidents of homeowners and tree workers when they’re using common tools of the trade, such as chain saws, chippers and pole saws, and now lifts and ladders.

Aerial lifts and ladders

A tree is defined as a perennial woody plant with a single stem that reaches a mature height of more than 15 feet. Most are far taller, of course, so accessing their canopies can be a challenge. It is enough of a challenge that this lofty environment was once the realm of climbers. Many tree owners were not foolhardy enough to try to climb their trees, though numerous exceptions occurred, often with grave consequences.

Truck-mounted aerial lifts became common in the 1950s. These allowed more workers to access canopies for arboricultural operations. The booms were mounted on large trucks, and, while the canopy could be accessed, it was often difficult to get the truck close to the tree. Unless the tree was along the street, navigating the vehicle around a house and through gates was a challenge, one that remains today.

But now the canopy has become a little crowded. It is no longer the domain of climbers or aerial-lift operators using truck-mounted booms, but instead includes anyone who can rent an aerial device. Drive by almost any rental business and you can find scissor lifts and an array of telescopic or articulating booms, usually trailer mounted, that anyone can use for tree work. Arborists also have taken advantage of the versatility of these newer aerial devices, so now many backyard trees can be reached by means other than climbing.

There also is a technology that predates aerial lifts that was used by early tree climbers – the ladder. We do not see these used by arborists much anymore. They were on every tree truck back in the 1960s and even into the ’70s, but the numbers have diminished. They still hang on the wall in many garages, however, and are readily available for homeowners doing tree work.

The incident data

The methodology for this article is like that for the other articles in the series. The data was collected through similar sources. Databases from the U.S. Bureau of Labor Statistics (Injuries, Illnesses and Fatalities program), U.S. Occupational Safety and Health Administration (OSHA) and hospital emergency-department visits are among the principal sources.

And an important reminder. The terms tree worker and arborist in this series apply to anyone paid to work on a tree. This includes landscapers, gardeners and other grounds workers, as well as arborists and others who are paid to work on trees. Also, laypeople are referred to as homeowners, though some of their incidents occurred while performing tree work not at home, but as volunteers at a playground or other community-maintained property.

This article, as the others in the series, focuses on the nonfatal injuries. There are many articles that provide details on the fatal injuries that occur to tree workers. Fatal incidents for homeowners doing tree work occur, but it is far more common for a serious injury to occur rather than a death.

Ladder nonfatal incidents

We will start out with ladders. These are the “go-to” means for every homeowner to get up into their tree canopy for pruning (or rescuing cats and kites). Ladders are simple, a series of rungs or bars, held between two lengths of wood, that are used as steps. Wood, fiberglass or metal are the common construction materials.

There were about 1.3 million nonfatal ladder incidents during the past decade that resulted in a visit to the local emergency department (ED). About 300,000 of these incidents resulted in an admission to the hospital. About 80% of the injuries were to homeowners, and 98% of these did not involve ornamental trees. These were mostly to homeowners who fell from the ladder while painting, roofing, cleaning gutters, doing interior home repair and even stringing Christmas lights.

If the ladder was used by a homeowner for tree pruning, often the incident narrative just noted it was a fall from a ladder while pruning, but without any details (29%). Other narratives were unclear as to the details (4%). But if the description of the tree-related incident was clear, there were two common reasons for a fall. One was that the cut branch struck the person, causing them to lose their balance and fall (23% of tree-related incidents). The other was that the ladder slipped off the trunk when a branch, bent beneath and supporting the ladder, was cut by the person (18%).

Other incidents occurred when the ladder slid away from the tree or branch due to unstable ground (12%). Some injuries happened by the extension-ladder section sliding down (8%) – these caused the hand fractures (ouch!) – or when a rung broke (6%).

While most ladder falls happened to homeowners, regardless of cause, about 20% were to workers, mostly construction. But tree workers were not exempt from injuries related to climbing ladders. Tree workers have about 300 nonfatal incidents while using ladders per year. A common one is being knocked from the ladder by a cut branch – just like what happens to homeowners. Another common cause of a fall, again just like homeowners, is having the ladder slide off the branch or tree due to unstable ground.

Don Blair, in his classic book, Arborist Equipment: A Guide to the Tools and Equipment of Tree Maintenance and Removal, gives some simple advice to avoid this problem. He suggests laying the ladder against a side limb when practicable, rather than against the trunk.

Two types of incidents occurred to tree workers that were not associated with as many homeowner falls. One was pruning with a pole saw while on the ladder and losing their balance. Another was stepping off the ladder into the tree and falling. These last two could have been avoided had the tree worker followed the Z133 standard, subsection 8.1.7, that requires workers to not work from or leave the ladder to access the canopy until they are tied in or secured.

These were not the only ladder-related incidents that appeared in the emergency department. There were also incidents where the ladder was not the primary source of the injury, but secondary to it. The person was on the ladder when the incident occurred, but the ladder was not the source of the injury. These were mostly lacerations from being cut by the chain saw or electrical burns from the metal ladder touching a conductor.

The nonfatal falls were from 4 to 30 feet, with the average being 17.5 feet. The injuries presented to the ED were fractures: rib, tibia/fibula, wrist and ankle. Other injuries included lacerations, dislocations and strains. The average age of the victim was 52.8 years old, with the range between 19 and 67 years.

Tree workers suffered the same injuries. The average height of the ladder fall was a little lower, 16.2 feet, and the falls ranged from 8 to 25 feet. The average age of a tree worker who presented to the ED due to a fall from a ladder was 45.5 years old, with the range between 19 and 76 years.

Aerial-device nonfatal incidents

There were about 2,400 aerial-device incidents during the past decade that resulted in a visit to the ED. The majority, about 96%, did not involve ornamental trees. Most occurred during construction or maintenance activities, though a few were the “cherry pickers” used in orchards.

Most of these did not occur to homeowners, the reverse of ladder incidents. While homeowners do rent lifts, they are most likely to be rented by tree workers hired by the homeowner to do pruning or removal, rather than being used by the homeowner. If a homeowner had an incident using an aerial device that resulted in a visit to the ED, the device was mostly used for painting, roofing, window washing or, once again, stringing Christmas lights, rather than trimming or removing trees.

In the incidents resulting in a homeowner trip to the ED as the result of a fall from the lift, the operators were not wearing any of the fall protection provided by the rental company. Many of these incidents were falls when the boom was struck by a falling branch, which caused the operator to tumble out of the platform, a common scenario for tree workers as well.

Homeowners also tumbled out of the platform when they opened the metal gate to grab a branch. They reached out to get to a cut branch that was lodged, lost their balance and fell. A few falls happened when the lift was used to push the top of the tree while someone was felling it. When the tree began to fall, the release of force caused the aerial-lift operator to be catapulted out.

One fall occurred when the operator was rigging branches from the platform. The sudden loading caused the lift to tip over and the homeowner jumped. There were also tip-overs as homeowners drove these self-propelled boom lifts over uneven ground (or over stumps). Regardless of the underlying cause for the fall, these nonfatal falls were from 10 to 40 feet, though most were less than 30 feet. The common injuries were fractures, mostly femur, clavicle and rib, though there were some wrist fractures and even skull fractures (they were not wearing helmets).

Another primary source of injury during lift operations by homeowners doing tree-related work was contact with an energized conductor. While lifts allow access to trees, they also shrink the distance between the homeowner and power lines, often to less than 10 feet. Although there were incidents of direct contact by their body, more commonly, nonfatal indirect contact was through a tool or the lift itself. The most common nonfatal injuries were electrical burns. Most of the rental aerial devices have decals that clearly warn they are not to be used within 10 feet of conductors, a warning that it appears is often ignored.

Not surprisingly, at an average of about 25 feet, the falls from rental lifts often occurred from greater heights than those when using ladders. The range was 16 to 50 feet. The average age of the lift operator was also a little older. Since flying a lift is less physically demanding than climbing, rental use spanned a wider age range. Unlike those involving ladders, aerial-lift falls included children as young as five! They were not doing the tree work, just going along for the ride.

Numerous articles have addressed the hazards of tree workers operating aerial devices, and I will not repeat these statistics here. If the aerial device was used for arboricultural operations, the emergency-department visit was from someone identified as a tree worker rather than a landscaper, though separation of the two is very vague in reports. The most common nonfatal incidents mirror those of homeowners. Operators fell from buckets or platforms when the boom was struck by a falling limb and the worker tumbled out – and they were not wearing fall protection.

Tree workers also suffered electrical shock either from the metal platform or a conductive tool contacting the conductor. Electrical shock also occurred to ground workers who were touching the aerial device when it was in contact with a conductor.

A sobering thought to all – tree workers led in electrocutions from aerial devices.

Final thoughts

There are fewer fall incidents with homeowners using aerial devices than ladders, but this does not imply that using mobile platforms is a lower risk – it is just that fewer use them.

Is there a solution to eliminating these all-too-common ladder-related incidents? Yes! The answer is deceptively simple: “When ladders are used in pruning and removal, the worker shall be tied in or secured before cutting from the ladder or transferring from the ladder into the tree.” Sounds like something right out of ANSI Z133, doesn’t it?

Since the majority of homeowners were not secured when injured, this simple precaution would eliminate most of those 911 calls. Of the few who somehow managed to secure themselves, even fewer were using arborist-grade personal protective equipment (PPE). Those doing landscaping and grounds maintenance also are all too often guilty of not taking common-sense precautions, such as being properly secured or tied in before commencing operations from ladders on shade and ornamentals, including palm trees.

While the type of incidents discussed here can occur with anyone – homeowners and tree workers – the fewest appear to involve professional arborists who are engaged in tree care as their full-time occupation. The landscapers and grounds workers who only enter tree canopies as an incidental part of their work would do well to leave the work aloft to the arborist.

Us Versus Them: The Series
“Chain-Saw Injuries: Us Versus Them,” by John Ball, Ph.D., CTSP, TCI Magazine, May 2021.
“Chipper Safety – An Analysis of Wood-Chipper Nonfatal Injuries: Us Versus Them,” by John Ball, Ph.D., CTSP, TCI Magazine, July 2021.
“Injuries Involving Handsaws and Pole Saws: Another Us Versus Them,” by John Ball, Ph.D., CTSP, TCI Magazine, January 2022.
“Tree Worker Safety Update by the Numbers: Another Us Versus Them,” by John Ball, Ph.D., CTSP, February 2022.

John Ball, Ph.D., BCMA, CTSP, A-NREMT (Advanced – National Registry of Emergency Medical Technicians), is professor of forestry at South Dakota State University and a Board Certified Master Arborist.

Donald F. Blair is president of Blair’s Arborist Equipment, LLC, in Hagerstown, Maryland, and has been a member of TCIA since 1982.