How NuDrive works

NuDrive consists of two Drive Units and two Wheel Adaptors; one pair for each wheel. Its 'Snap-Lock' technology allows the Wheel Adaptor to be fitted in seconds, without altering any of the wheel configurations. Once in place, the lightweight design adds no width and can be left unobtrusively positioned on the wheel also allowing unhindered removal of the wheels for transport. When you want to use NuDrive, the Drive Units can simply be clicked into place and then removed when finished.

NuDrive enables easier forwards and backwards propulsion, manouvering, and braking and features an inclusive control system that requires no hand or finger dexterity - all control is achieved thorough simple arm and shoulder movements.

To propel the chair, first put NuDrive into 'drive mode' with an effortless outward flick of the levers. Once in 'drive mode' you can propel yourself forwards simply by pushing the levers. To brake and steer, pull the levers inward, towards the body. NuDrive's intuitive braking system also makes reversing easy: first return to 'neutral mode' with another outward flick of the levers, and then using the product brakes, grip and move the wheels in the desired direction.

Technical specification

NuDrive is available in one size that will fit almost any 24" metal spoked wheel. Maximum user weight 300lbs / 21 stone / 136kg.

Wheel Adaptor (x2)

Lightweight aluminum construction, globally compatible, one-time adjustment, snap-lock fitment, quick-release disconnection, zero additional width.

1.07kg each

Drive Unit (x2)

Lightweight aluminum construction, snap-lock fitment, quick-release disconnection, forward drive, braking system, transmission, height-adjustable / comfy-touch handle.

1.44kg each

NuDrive is designed to be ultra-slim by utilising precision engineered high specification materials. The Wheel Adaptor adds virtually no width. The table below indicates the width that each Drive Unit adds according to the camber of the wheels:

The above widths are calculated with the levers pulled inwards and brakes applied for manoeuvring through narrow spaces.

Demo video

Please view the videos relating to the NuDrive (accessible from this page or from the Resources, Video page).

NuDrive - a solution

Medical research indicates that reducing the force needed to propel a chair helps to protect the arms and shoulders of wheelchair users. Existing clinical research also shows that lever-drives can shift the shoulder loading and, in this way, reduce shoulder degradation and injury.

Experts at the University College of London and the Aspire Centre for Disability Sciences have been involved in the development of NuDrive on a consultancy basis, and have provided the following statement on the speculated functional and health benefits of lever drive systems for wheelchair propulsion:

There are several potential mechanisms via which, NuDrive can increase functional independency in wheelchair use. Belonging to the category of lever-based propulsion systems, NuDrive might have a higher mechanical efficiency ^1-3, impose less physical burden at a given propulsion condition ^1,4,5, be able to reduce the required propulsive force and foster more effective propulsion ^1,6-8,14, improve trunk and upper limb joints' posture and reduce predisposition to neuro-musculoskeletal pathology ^9-12, delay fatigue ¹³ and improve quality of life by enhancing remaining functional abilities and allowing participation in life situations ¹⁵.".

Clinical studies for NuDrive are currently being planned in conjunction with the Aspire Centre for Disability Sciences.

Clinical research

Propulsion problems (See pdf file "Shoulder Joint Loads Using Handrims")

There is extensive evidence to show that prolonged over-exertion during manual wheelchair propulsion can result in chronic damage to the shoulder joint and other structures. The risk of damage is thought to be higher for children because of their lower upper body strength. Recent medical research has highlighted the fact that propelling a wheelchair using the push rim produces high directional shoulder forces, and this correlates with coracoacromial arch pathology as shown by an MRI scan, and also physical discomfort. That research recommended that researchers and clinicians find ways to reduce the forces and moments experienced by the shoulder during wheelchair propulsion Modified wheelchair design including a new method of self propulsion is a way to achieve this, without the loss of freedom for the chair user.

NuDrive - a solution using lever-drives (See pdf file "Shoulder Joint Loads Using Lever Drives")

Pure Global's NuDrive system uses a lever action with mechanical advantage to reduce the force needed to propel the wheelchair, while at the same time changing the action needed to one which is gentler on the upper body muscle groups.

A new study funded by the National Institute of Disability in the USA shows that lever propulsion systems shift the shoulder joint load by decreasing the superior glenohumeral force while increasing the range of motion. They also found lower posterior shoulder force and decreased adductor moment. Together these reduced demands on the shoulder have the potential to reduce commonly experienced shoulder pain and injury, preventing long-term shoulder degradation.

Additional advantages: replacing heavy and expensive carer assisted products

Early field trials carried out by Pure Global's research partner, the Aspire Centre for Disability Sciences (ACDS), shows that NuDrive has the potential to act as a cost-effective lightweight alternative to battery powered carer assisted products. The results of this study will be available soon and will be posted here.

References and research papers

Please find below a reference list for the medical statement provided by the University College of London.

1. van der Woude LH, Veeger HE, de Boer Y, Rozendal RH. Physiological evaluation of a newly designed lever mechanism for wheelchairs. J Med Eng Technol 1993; 17:232-240.
2. Veeger HE, van der Woude LH, Rozendal RH. Effect of handrim velocity on mechanical efficiency in wheelchair propulsion. Med Sci Sports Exerc 1992; 24:100-107.
3. van der Woude LH, Botden E, Vriend I, Veeger D. Mechanical advantage in wheelchair lever propulsion: effect on physical strain and efficiency. J Rehabil Res Dev 1997; 34:286-294.
4. Engel P, Hildebrandt G. Wheels: Wheelchair Design - Technological and Physiological Aspects. Proc Roy Soc Med 1974; 67:409-413.
5. Engel P, Seeliger K. Technological and physiological characteristics of a newly developed hand-lever drive system for wheelchairs. J Rehabil Res Dev 1986; 23:37-40.
6. Robertson RN, Boninger ML, Cooper RA, Shimada SD. Pushrim forces and joint kinetics during wheelchair propulsion. Arch Phys Med Rehabil 1996; 77:856-864.
7. Guo LY, Zhao KD, Su FC, An KN. Moment generation in wheelchair propulsion. Proc Inst Mech Eng [H ] 2003; 217:405-413.
8. van der Woude LH, Veeger HE, Dallmeijer AJ, Janssen TW, Rozendaal LA. Biomechanics and physiology in active manual wheelchair propulsion. Med Eng Phys 2001; 23:713-733.
9. Veeger HE, Meershoek LS, van der Woude LH, Langenhoff JM. Wrist motion in handrim wheelchair propulsion. J Rehabil Res Dev 1998; 35:305-313.
10. Mercer JL, Boninger M, Koontz A, Ren D, Dyson-Hudson T, Cooper R. Shoulder joint kinetics and pathology in manual wheelchair users. Clin Biomech (Bristol , Avon ) 2006; 21:781-789.
11. Yanai T, Hay JG, Miller GF. Shoulder impingement in front-crawl swimming: I. A method to identify impingement. Med Sci Sports Exerc 2000; 32:21-29.
12. Boninger ML, Dicianno BE, Cooper RA, Towers JD, Koontz AM, Souza AL. Shoulder magnetic resonance imaging abnormalities, wheelchair propulsion, and gender. Arch Phys Med Rehabil 2003; 84:1615-1620.
13. Mukherjee G, Samanta A. Physiological response to the ambulatory performance of hand-rim and arm-crank propulsion systems. J Rehabil Res Dev 2001; 38:391-399.
14. Harrington, T. and Murphy, G. Lever propulsion design for manual wheelchairs. Bioengineering Conference. Proceedings of the IEEE 30th Annual Northeast 2004; 210-211.
15. Van der Woude LHV, Dallmeijer AJ, Janssen TWJ, Veeger D. Alternative modes of manual wheelchair ambulation - An overview. American Journal of Physical Medicine & Rehabilitation 2001; 80:765-777.

Patents on the technology are currently pending in the UK, USA, Europe, Japan and China.