Wheeling in the New Millennium: The history of the wheelchair and the driving forces in wheelchair design today

Dr. Bonnita Sawatsky, Department of Orthopaedics, British Columbia's Childrens Hospital, Vancouver, BC, Canada

Slide 1: Overview

• Historical background
• Design issues
• Current research
• Pilot study
• Where we should go?

Slide 2: History

• Man’s two earliest inventions
• Chair
• Wheel
• 4000 B.C.
• Originated in eastern Mediterranean basin

Slide 3: History

• First record of combining wheels to furniture
• Image on Greek vase of wheeled child’s bed
• 530 B.C.

Slide 4: China

• Spoked wheels on chariots 1300 B.C.
• Oldest evidence of wheeled chairs
• 525 A.D. engraving of one of the earliest representation of a wheeled chair

Slide 5: Wheelbarrow

• 3rd century invention from China
• Used for moving the sick or disabled to the “Fountain of Youth”

Slide 6: “Gestations”

• Greek and Roman physicians prescribed a “gestation” or transportation for the sick or disabled (1553)
• Get people out into fresh air and help work with whatever they could do in the fields.
• Carried on a sedan or push on a chair with wheels

Slide 7: Spain

• King Phillip II (1595) of Spain
• Had his own rolling chair with foot rests

Graphic Description:

Slide 8: Self-propelled chair

• Paraplegic watchmaker, Stephen Farfler (1655) built his own chair at 22 yrs of age.

Graphic Description:

Slide 9: “Bath” chair

• Developed in Bath, England
• Invented by John Dawson, “Wheel-chair maker” 1783
• Dominated the market of 19th century
• Two large wheels, one small wheel

Graphic Description:

Slide 10: “Seating”

• Comfort for the disabled person became more of an issue
• Convertible chair (reclining back and adjustable foot rests)
• 18th century

Graphic Description:

Slide 11: Wheelchair to Bicycle

Notes:
The developments in the wheelchair probably led to the development of the bicycle.

Slide 12: Manual to Motor

• Self-propelling chair operated by a crank axle connected to a steering rod for the front wheel
• Inspired the first tricycle

Graphic Description:

Slide 13: Bicycle

• 1790, de Sirvac (France) invented the celerfere “swiftwalker”
• Wooden bicycle propelled by user by pushing feet on ground
• 1865, velocipede, with added cranks and pedals “boneshaker”

Graphic Description:

Slide 14: Bicycle to Wheelchair

Graphics Description:

Slide 15: Bicycle to wheelchair

• 1867 - changed wooden wheels to iron
• 1875 - added hollow rubber tires

Graphic Description:

Slide 16: Bicycle to wheelchair

• 1881 - pushrims were added for propulsion
• 1900 - wired spoked wheels adopted by wheelchairs
• 1912 - 1 3/4 horsepower engine was attached to a invalid tricycle
• 1916 - London produced first motorized wheelchairs

Slide 17: “Lightweight wheelchair”

• Made from Indian reed
• Large wheels either front or back
• 58 lbs. with pushrims
• 50 lbs. without pushrims

Graphic Description:

Slide 18: The Automobile led to more changes

• Herbert A. Everest
• Wanted a wheelchair that could go in an automobile
• Teamed with engineer, HC Jennings, to manufacture first folding metal WC
• 1933, Los Angeles

Slide 19: Samuel Duke

• 1934
• Independently of E & J responded to demand in Chicago
• Developed the 2nd manual, lightweight, “folding” wheelchair for the market

Slide 20: Cause of change in WC

• Introduction of the automobile
• Need to get wheelchairs into cars
• Increased # of injuries due to automobiles
• Development of rehab and re-education programs for injured
• Improved medical services
• Demand of independence of disabled people

Slide 21: Wheelchair Sports

• Introduced as a form of therapy in the rehab program Stoke Mandeville Hospital in Aylesbury, England
• Annual World Stoke Mandeville Wheelchair Games
• >70 countries now in International Stoke Mandeville Wheelchair Sports Federation

Slide 22: Wheelchair sports

• Athletics, rugby, tennis, basketball, etc.
• Rigid chairs!

Graphic Description:

Slide 23: Wheelchair sports

• Improved the physical function of disabled people.
• Created more active individuals who want to do more.
• Increased the demand for “performance” in their manual wheelchairs.
• Lightweight, versatility, stability, and endurance.

Slide 24: Materials

• Steel - most researched and longest used metal for bikes and manual wheelchairs
  • Largest selection and most affordable
• Aluminum - very light and relatively inexpensive
  • Minimal bending strength, requires largest sized tubing to get enough strength
  • Least flexible, brittle

Graphic Description:

Slide 25: Materials

• Titanium - best strength to weight ratioT(Titanium - best strength to weight ratio
  • Greatest flexibility
  • Costly 15 x more than steel
• Carbon fiber - used to mold a frame, boat builders material
  • Less expensive than titanium
  • Strong, yet flexible
• Chrome alloy - most common
  • ENDURANCE (strength)

Graphic Description:

Slide 26: Issues

• Lightweight
• Versatility
• Stability
• Endurance

Slide 27: LIGHTWEIGHT!

• Finally lightweight chairs that are really light weight 20-25 lbs.
• Purpose:
  • Decreased energy cost
  • Reduce shoulder and wrist injuries due to repetitive strain
  • Easier to transport

Slide 28: Camber

• STABILITY
• Decrease incidence of injuries from falling or tipping
• Decrease energy cost
• More ergonomic (positioning)
• Easier turning ( inertia )
• Adjustability ( VERSATILITY)
• “no tools” camber adjustment
  

Graphic Description:

Slide 29: WE HAVE IT ALL!

• Lightweight
• Stability
• Endurance
• Versatility
• What else do we need?

Slide 30: Suspension (bicycles)

• Decreased the shock sent to body

Pneumatic tires

• Softer tires rolling resistance

Shocks

• Coil springs
• Lever arms
• Bumpers

Graphic Description:

Slide 31: Suspension manual wheelchairs: “You name it, they got it”

• Front suspension
• Rear suspension
• Increased cushioning?
• Wheeling cost?
• Up or down

Graphic Description:

Slide 32: What do we really need?

• Chairs which require minimal energy to propel
  • Low rolling resistance
  • Lightweight
  • Ergonomically efficient
• Chairs that provide support and comfort
  • Molded seating (adjust for deformities, minimize potential for pressure sores)
  • Cushioning (padding or shock absorbers)

Slide 33: What are researchers doing?

• Summary of research 1999
• Materials strength:
  • “Fatigue life of manual wheelchair cross-brace designs” Cooper et al., 1999.
  • Evaluation of selected ultralight manual wheelchairs using ANSI/RESNA standards. Cooper et al., 1999

Slide 34: What are researchers doing?

• Summary of research 1999
• Biomechanics of wheeling:
  • Glenohumeral joint kinematics and kinetics for three coordinate system representations during wheelchair propulsion. Cooper et al, 1999
  • Assessment of geometric and mechanical parameters in wheelchair seating: a variability study. Maltais et al.,1999

Slide 35: What are researchers doing?

• Summary of research 1999
• Clinical research of wheeling:
  • Shoulder pain in wheelchair users with tetraplegia. Curtis et al.,1999
  • Wheelchair pushrim kinetics: Body weight and median nerve function. Boninger et al., 1999

Slide 36: What are researchers doing?

• Summary of research 1999
• Energy cost of wheeling:
  • Energy cost of propulsion in standard and ultralight wheelchairs in people with spinal cord injuries. Beekman et al.,1999.
  • Ultralight wheelchairs significantly improved the efficiency of propulsion in paraplegics and tetraplegics

Slide 37: Analysis of the O2 cost of wheeling

• Measures how much energy a person uses during a given task.
• Theoretically, the less energy required for wheeling the better the chair
• Less energy used for wheeling, the more energy available for daily living activities
• Relates to wheelchair users

Slide 38: Relevant outcome criteria

• Energy cost: requires minimal energy throughout the day to propel through various environments
• Comfort: allows for long term use with minimal risk to pressure points
• Adjustability: ability to adjust chair for good biomechanics for a variety of activity needs (minimize risk to shoulder and wrist injuries)

Slide 39: Pilot study

• Compare 3 types of chairs:

1. lightweight rigid chair
2. lightweight rigid chair w rear suspension #1
3. lightweight rigid chair w rear suspension #2

• O2 cost analysis on level smooth surface
• ml/kg/m (5 min trials)

Slide 40: Energy expenditure

• Cost of locomotion
  • Wheeling

Graphic Description:

Slide 41: 02 cost of wheeling with suspension

• Case study:
• 21 yr. old male, Nemeline myopathy
• Full time W/C user since birth
• Three conditions:
  • Rock Shox (spring suspension)
  • Action chair (polymer block suspension)
  • Rigid Titanium (no suspension)

Slide 42: O2 data: Averaged

Graphics Description:

Slide 43: O2 cost of suspension chairs

Graphics Description:

Slide 44: Pilot study: Conclusion

• Small study
• Suspension chairs require a significant increase in O2 cost (more work) in wheeling on level surface (dense carpet).
• Must consider O2cost in trade offs for suspension or not in wheelchair prescriptions
• Suspension may not be suitable for weak or low endurance clients
  

Slide 45: Cost / Benefit analysis

• Knowing the relative cost of adding suspension to a chair one can weigh the benefits of adding suspension to the costs

Slide 46: What are the real issues?

• Listen to the users and pass on the concerns to the researchers so that relevant research can be implemented.
• Team up with researchers in the community
  • Users
  • Therapists
  • Wheelchair Providers/manufacturers
  • Researchers

Slide 47: Acknowledgements

• Motion Specialties
• Randy (Sunrise Medical)
• Charles (Invacare)

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Updated: June 13, 2002