July 2011

Navigating stairs can be tricky

By Joe Deering

Being injured in an accident is never a pleasant experience. From the associated injuries to the lengthy recovery, accidents cause inconvenience and hardship. This can certainly be the case with accidents related to slips, trips, and falls. Fall-related injuries are the leading cause of nonfatal, unintentional injuries treated in hospital emergency rooms. Deficiencies in design, lighting, visibility, and attention are usually the culprits in stairway slips, trips, and falls.

Research studies found that during stairway use, people view only the first and last three steps, with the rest of the stairway negotiated without looking. Therefore, design of the top three and bottom three steps is very important. All tread and riser dimensions should be uniform throughout the entire stairway. Most building codes require risers not to vary more than 3/8 of an inch between the tallest and the shortest riser within a given flight of stairs; riser heights should be 4 inches minimum and 7 inches maximum. Minimum tread depth should be 11 inches, and stairways with more than 12 steps should have an intermediate landing.

More serious upper and/or lower extremity injuries can occur when traveling down a stairway than when traveling up a stairway. In stairway descent, the tread depth or horizontal surface must be adequate for the ball of the foot to land on the tread without extending over the step below. If not, an over-step or misstep can occur, causing a fall forward. Trips and falls occurring during stairway ascent are often attributed to a variation in riser, or vertical surface, height.

As people descend a stairway, the floor below and the treads are in their line of sight, but the risers are not. Poor visibility of both risers and treads can lead to misreading the stair edge, which can cause faulty foot placement and an accident.

Adequate lighting should be installed to highlight the stairway and the floor approaching it on both levels. Make sure the edge of each tread is properly illuminated, and aim the lighting so that shadows are not cast on the stairway and glare does not disrupt the vision of those approaching the stairway. Ensure stairways are lit at all times. Back-up power is especially critical for stairway lighting.

A significant number of “air step” falls – stepping off the top of a stairway into air – due to a lack of attention occur on low stairways consisting of one, two, or three steps. In effect, people step off into thin air, not having seen the stair or stairs at all. “Air step” falls commonly occur because people fail to perceive the modest change in floor level and are usually the most serious accidents on low stairways. Contrasting the stairways and the landings with anti-skid strips and/or a variation in color will help reduce “air step” falls.

Accidents related primarily to slipping can happen for a number of reasons. This is especially true in the workplace. To avoid being the victim of a slip, trip, or fall accident:

• Use caution on slippery surfaces – any surface with water or moisture holds the potential to be highly hazardous;
• Use handrails when making use of stairs; and
• Do not carry heavy or large objects while using the stairs.

Many stairway accidents occur due to poor maintenance. Keep stair treads clean and in good condition. There should be no excessive wear, missing treads, or loose treads. Carpeted stairs should be in good condition with no noticeable deterioration. Never use stairs for storing objects. Do not carry items in the hands on stairs, and do not rush up or down stairs.

By knowing the steps to remain out of harm’s way, employees will be better able to avoid falling victim to slip, trip and fall accidents on stairways.

Joe Deering is a risk management specialist in the Risk Assessment and Loss Prevention division.