Presentation at National Association of Subrogation Professionals National Conference in November 2012.

1. Subrogating the
Slip and Fall Claim
John Leffler, PE
FORCON International
Atlanta
Robert F. Horn, Esq.
White and Williams LLP
Philadelphia

2. Overview
 Thousands of slip-fall events occur every year
• Primary causation is walkway traction
• A high-energy fall & significant or fatal injuries may result
 Some entity created each legitimately slippery
walkway, or allowed it to exist
• Subrogation may be viable, if an unreasonable hazard exists
• The claimant’s legal status on the premises & the duties of
other parties must be analyzed
 Evaluating walkway traction is important
• Reliable traction testing can be a key for recovery
• Different jurisdictions have had varied holdings regarding
this testing

3. Typical claimants
 Employees
• At primary worksite - engaged in work tasks or during
transitions
• At client’s or vendor’s location
• In transit (airports, restaurants)
 Visitors
• Customers
• Contractors working onsite
• Vendors making deliveries
• Passersby

4. Intrinsic and extrinsic factors
 Slip-fall investigations may warrant analysis of:
• Intrinsic elements: the claimant
– pre-existing medical conditions
– medications
– fall kinematics & biomechanics
– expected vs. unexpected injuries
• Extrinsic elements: the surrounding environment and
walkway
– walkway traction
– contaminants

5. Common types of slip events
 Heel strike (straight and curved travel)
• Leading heel contacts walkway & slides
• Forward momentum exacerbates the slip
• Leading leg cannot support body weight
 Toe-off
• Trailing foot slips as the toes push off
• Rarely results in a fall – most weight has shifted to leading leg
 Fore-aft split
• Lower extremities not strong enough to keep from spreading into an
increasing-length stride
• Fall to the side is typical - elderly persons

6. Walkway traction &
testing

7. Introduction: Walkway Traction
 Traction is related to:
• Coefficient of friction (COF) between two surfaces,
typically separated into:
– static: maximum when about to move (SCOF)
– dynamic: maximum when about to stop (DCOF)

8. Introduction: Walkway Traction
 Pedestrian traction is related to:
• Slip resistance:
– “The relative force that resists the tendency of the shoe or foot
to slide along the walkway surface. Slip resistance is related to
a combination of factors including the walkway surface, the
footwear bottom, and the presence of foreign materials
between them.” [ASTM F1646]
• Slip resistance is more than just a COF
measurement - involves issues with the pedestrian

9. Walkway Traction
 Codes & standards require walkways to be slip
resistant – without defining how this is to be
determined
• Past efforts to require specific traction levels have all been
withdrawn
• To require a particular traction level would require agreement
about which devices and methodologies to be used for testing
slip resistance - and there are no such agreements
• The absence of codified test methods opened the door to
“experts” that use arbitrary, homegrown, or otherwise
subjective methods - in testimony

10. The Range of Values for Traction
 In human subject research
• Values for traction demand range from COF
of about 0.17 – 0.40 in human slip research
 Popular concept: a value of 0.5 is the “threshold”
for adequate walkway traction
• 0.5 value commonly referenced for 60 years
– reliable scientific foundation for this is lacking
– test methods & research have continually evolved & improved -
reducing the needed “safety factor” for some analyses
– there can be no “one size fits all” threshold value for safe
walkway traction – there are too many variables

11. Walkway Traction Testing
 The two most robust ways to attempt to determine
the adequacy of walkway traction are:
• Relevant human subject lab testing
• Competent use of a walkway tribometer,
on appropriate surfaces, with scientifically
defensible interpretation of the results
 Various designs of tribometers are used to analyze
walkways
• Each device & method has its advocates - a source of much
controversy
• Each device may provide different measurement values for the
same surface!

12. Walkway Traction Testing
 The new perspective
• Tribometer measurements must be reliably correlated
to actual pedestrian slip experiences
– Correlation established through testing with human
subjects and tribometers
• A “reliable” tribometer:
– will discriminate surfaces found “slippery” (by humans),
from those found to be reasonably slip resistant
– will not necessarily provide the same numerical values (for
slip resistance) as other reliable tribometer designs - but
this is OK

13. General Features of Tribometers
 Testfoot: the simulated “shoe” or “foot” that
contacts the walkway surface
 Types of tribometers (common in USA)
• Dragsleds: manual and motorized
• Articulated strut – designs loosely based on human motion
 Technical issue with some tribometer designs
• Adhesion or “sticktion”
– If the testfoot rests motionless on the walkway surface for even
an instant, molecular bonding (“sticktion”) occurs
– All dragsleds have sticktion in SCOF testing – known for
decades

14. Tribometers
 Manual dragsleds
• Horizontal Dynamometer Pull Meter
(C1028)
• Technical Products Model 80
• American Slip Meter 825
 Motorized dragsleds
• Horizontal Pull Slipmeter
• BOT 3000

15. Tribometers
 Articulated strut
• Brungraber Mark II PIAST
– uses a 10 pound weight for
testfoot actuation
• Brungraber Mark III PIAST
– uses a spring for testfoot
actuation
• English XL VIT
– uses a CO2 cartridge
for testfoot actuation

16. Tribometer Testing Issues
 Surface contouring and coarse texturing may
be too “severe” to provide consistent results
 Contaminant issues in tribometer testing:
• Soft contaminants may accumulate on the testfoot
• Loose surface finishes and crumbly
fragments of contaminants will affect results
– varied positions of larger fragments
– compliance of testfoot material around large
fragments versus compliance of footwear
– reduced contact pressure of testfoot versus
a pedestrian– soft fragments crush less

17. Comments: Tribometers & Testing
 ASTM standard test methods for the English XL &
Brungraber Mark II have been withdrawn – but
the machines still work & may be the best choice
 The expert must be an expert, not just a machine
operator
• Operation of the tribometer is only part of a robust, defensible
analysis
• Competent experts will be aware of recent research, new standards,
and the need for reliable correlation to human slip experiences
• The era of subjective, indefensible testing is ending
• Competent counsel will know of competent experts

18. Walkway Surface
Issues to Consider

19. Walkway Surface Basics
 Roughness & asperities
• Surface roughness: the average height of the
microscopic surface features of the walkway
– a very general way to view a surface’s traction
• Surface asperities: “individual” microscopic features
that protrude above the basic “average” surface
– high, sharp asperities cut through contaminants and are
mechanically (and molecularly) gripped by the footwear

20. Walkway Surface Basics
 Roughness & asperities
• Smooth flat walkways (without much roughness or
asperities) rely more on molecular bonding and
adequate time for the shoe to “squeeze out”
contaminants
• Distribution of asperities will vary significantly on some
surfaces - so traction will vary as well
 All normal walkways have contaminants
• The unreasonably hazardous contaminants are the
concern

21. Walkway Surface Types
• Manufactured
• concrete pavers and blocks, ceramic tile,
prefinished wood planks, marble, terrazzo, bricks,
vinyl tile and sheet, plastic/sawdust deck boards,
metal grating & plates, carpet & mats
 Fabricated (onsite)
• sanded wood boards, concrete, asphalt, liquid
polymers
 Natural
• slate, rock, stone, gravel

22. Walkway Slope Effects
 All slopes will affect traction
• Gravity causes an increase in required traction
• Slopes & ramps are typically most slippery downhill
• Many tribometers don’t work on slopes
• Slope effects are ignored by many “experts”

23. Walkway Surface Finishes
 Types of coatings
• Paints, stains, acrylic sealers, varnishes
– A liquid solvent or carrier, with solids, polymers, pigments
– Traction additives (grit) may be added
• Waxes, polishes
• Adhesive “rubbery” coatings
 Balance benefits/disadvantages
• Coatings typically improve appearance and ability to
keep the walkway clean
• Coatings typically reduce traction

24. Briefly: Bathing Surface Traction
 Bathing surface slip-falls are common
 Slip resistance requirements: metal tubs
• Are based on 1977 standardized test method (ASTM
F462) that uses obsolete tribometer
• Were never based on human falls, just manufacturer
capability
• Requirements only apply while tub is under warranty
 Slip resistance requirements: plastic tubs
• Reference to F462 testing eliminated in 2005
• Only subjectively required to be “slip resistant”

25. Briefly: Bathing Surface Traction
 Commercial properties can be expected to have
slip resistant features in bathtubs
• Features may wear significantly over time
• Add-on treatments (coatings with grit) are available
 Most tribometer testing of bathtubs can be
challenged on reliability and relevance
• Tribometers typically use testfeet designed to simulate
shoe soles, not bare feet
• Bathtub surfaces are typically convex; testfeet are
planar

26. Subrogation Targets:
Who Created or Allowed the Hazard?
(Assuming we’ve shown the slip hazard exists)

27. Who Created the Slip Hazard Initially?
 Manufactured walkway surfaces
• manufacturer, designer, installer
 Fabricated walkway surfaces
• designer, installer
 Natural walkway surfaces
• designer, installer
 Finishes
• manufacturer, designer, installer

28. Who Created the Slip Hazard Pre-Incident?
 Finishes
• Floor maintenance subcontractor
• Cleaning chemicals & supplies providers, service techs
 Contaminants
• Contractors - construction debris and spills
• Water accumulation
– Landscape sprinkler issues
– Roof drainage issues
– Water management issues of neighboring properties

29. Who Allowed the Slip Hazard to Exist?
 Property possessors
• Worn-smooth surfaces
• Flaking or loose coatings
• Grit or texture additives worn away
• Hazardous contaminant accumulation: lax housekeeping
 Vendors
• Contractors for remodels and additions
– OSHA Multi-Employer Worksite
» Controlling Employer (able to compel hazard abatement)
» Correcting Employer (assigned to correct hazards)

30. Other Issues to
Consider...

31. What Duty is Owed to the Claimant?
 The duty of care owed to visitors by the
property possessor depends on the visitor’s
legal status, and state law.
 The traditional standards are:
• Invitee: shopper, client
– Duty: reasonable care + higher duty of inspection
• Licensee: by consent, social guest
– Duty: reasonable care
• Trespasser: no legal right to be there
– Duty: refrain from willingly injuring, or from
wanton conduct

32. What Duty is Owed to the Claimant?
Alternative Legal Duty Analysis
 Was the plaintiff lawfully or unlawfully on
the property?
• Lawfully: reasonableness standard
• Unlawfully: refrain from willful/wanton conduct
Applies in: IL, IA, NE, ND, WI

33. Was the Duty Owed Breached?
 Defendant must have notice of the
hazardous condition in order to have
breached his duty.
• Did the defendant breach his duty of care owed to
the claimant?
– Actual knowledge of slip hazard?
– Should have known of slip hazard?
• Timeliness of notice
• Practice and procedures of inspection

34. Other Extenuating Circumstances?
 Claimant has contributory intrinsic issues
 Industrial plants & bulk contaminants
• foreseeable?
 Person trained in the specific hazard, or the
hazard is open & obvious
 Property possessor performs reasonable
periodic maintenance
 Failure to maintain a proper lookout

35. Conclusions
 Slip-fall incidents can be deadly
 Proving a workers’ comp subrogation slip-fall
case requires establishing causation through the
use of competent expert testimony
 Depending upon the hazard, many different
entities may be reasonable targets for a
subrogation action

36. Thank you!
John Leffler, PE
JLeffler@forcon.com
(800) 390-0980
Robert F. Horn, Esquire
HornR@whiteandwilliams.com
(215) 864-7132