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
- Mans two earliest inventions
- 4000 B.C.
- Originated in eastern Mediterranean basin
Slide 3: History
- First record of combining wheels to furniture
- Image on Greek vase of wheeled childs 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
Slide 8: Self-propelled chair
- Paraplegic watchmaker, Stephen Farfler (1655) built his own chair at 22 yrs of age.
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
Slide 10: Seating
- Comfort for the disabled person became more of an issue
- Convertible chair (reclining back and adjustable foot rests)
- 18th century
Slide 11: Wheelchair to Bicycle
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
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
Slide 14: Bicycle to Wheelchair
Slide 15: Bicycle to wheelchair
- 1867 - changed wooden wheels to iron
- 1875 - added hollow rubber tires
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
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
- 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!
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
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
Slide 26: Issues
Slide 27: LIGHTWEIGHT!
- Finally lightweight chairs that are really light weight 20-25 lbs.
- Decreased energy cost
- Reduce shoulder and wrist injuries due to repetitive strain
- Easier to transport
Slide 28: Camber
- Decrease incidence of injuries from falling or tipping
- Decrease energy cost
- More ergonomic (positioning)
- Easier turning ( inertia )
- Adjustability ( VERSATILITY)
- no tools camber adjustment
Slide 29: WE HAVE IT ALL!
- What else do we need?
Slide 30: Suspension (bicycles)
- Decreased the shock sent to body
- Softer tires rolling resistance
- Coil springs
- Lever arms
Slide 31: Suspension manual wheelchairs: You name it, they got it
- Front suspension
- Rear suspension
- Increased cushioning?
- Wheeling cost?
- Up or down
Slide 32: What do we really need?
- Chairs which require minimal energy to propel
- Low rolling resistance
- 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:
- lightweight rigid chair
- lightweight rigid chair w rear suspension #1
- lightweight rigid chair w rear suspension #2
- O2 cost analysis on level smooth surface
- ml/kg/m (5 min trials)
Slide 40: Energy expenditure
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
Slide 43: O2 cost of suspension chairs
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
- Wheelchair Providers/manufacturers
Slide 47: Acknowledgements
- Motion Specialties
- Randy (Sunrise Medical)
- Charles (Invacare)
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Updated: June 13, 2002