Biomechanics of wheelchair transfers

Biomechanics of wheelchair transfers

posted on - 2022-12-26

Vehicle travel is a sign of society’s independence, community, and vocational engagement, regardless of the type of locomotor mobility issues a person has. Unfortunately, the current workplace scenario is such that talent is restricted only to people who can travel to their workplace, which is non-feasible. 

Our survey records suggest that in India, the percentage distribution of car owners with locomotor mobility issues is 35% of sedans, 25% of small/hatchbacks, and 40% of MPV/SUV-type vehicles. These include elderly, muscular dystrophy, multiple sclerosis, spinal injury, Parkinson’s, Lennox-gastaut, passengers, etc. 

The main issues that hinder vehicle travel include:

  1. Vehicle height, door gap, door opening
  2. Lack of holding areas within and exterior of a car
  3. Joint stress and muscular fatigue on the left body side (shoulders) when entering the car from the left side
  4. The lack of degrees of motion for the neck and upper body makes ingress difficult.
  5. Age-related muscular movements for such a complex human motion.


Figure: Shows a biomechanics model of Ingress/Egress from a vehicle with stress distribution indicated using a color range, credit: BoB biomechanics modeling software


Lack of access to cars and travel for persons of any age can cause the following issues:

  1. No access to hospitals and advanced medical treatment
  2. Lack of access to on-site therapy
  3. Psychology problems
  4. Restrictions on freedom to work independently


Other places where people transfers are complex:

  1. Wheelchair-to-bed
  2. Wheelchair-to-house seating
  3. Wheelchair-to-car (the most complex of all transfers)
  4. Wheelchair to washroom

Note: a functional upper body, primarily shoulder functionality, is most important for all the above transfer motions, where lack of it can seriously hinder ease. 

Parameters to check vehicle transfer ease-

  1. Average passenger loading time (in minutes)
  2. Average passenger unloading time (in minutes)
  3. Helper effort (a particular set of parameters)
  4. Passenger effort (a particular set of parameters)



  1. Journal- frontiers in bioengineering and biotechnology

Car Transfer and Wheelchair Loading Techniques in Independent Drivers with Paraplegia, by Lisa et al.

For more information and advice:

Caruna seatings is an Indian-based manufacturer that provides such wheelchair-to-vehicle devices. Persons interested may Whatsapp the following numbers for inquiries and advise: +91 80723 36673, +91 94898 76146

Currently, Caruna is taking orders in Mumbai (& Maharashtra state), Bangalore (& Karnataka state), Hyderabad (& Andhra state), Chennai (Tamil Nadu state).

The basic model price starts from Rs 94,500/- onwards.




More on the founder:

Ashwin Shreshta, the founder of Caruna seating, is an Indian educated in RWTH Germany, specializing in automotive engineering. Ashwin holds three patents in assistive mobility, advanced tracking, and electric wheelchairs. Ashwin’s passion is to manufacture indigenous state-of-the-art wheelchair products to benefit differently-abled and elderly passengers.

Our Partners whatsapp +918072336673
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