Lever Drive; A Solution for Some of the Upper Body Problems Experienced by Wheelchair Users.
Medical research indicates that reducing the force needed to propel a chair helps to protect the arms and shoulders of wheelchair users. Lever systems like NuDrive have been shown to reduce the strain on these parts of the body.
The Problem
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 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 (View research paper). 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 drive
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 (View research paper). Together these reduced demands on the shoulder have the potential to reduce commonly experienced shoulder pain and injury, resulting in the prevention of long-term shoulder degradation.
Additional Advantages; Replacing heavy and expensive carer assist products
Early field trials carried out by Pure Global's research partner the Aspire Centre for Disability Sciences (ACDS) show that NuDrive has the potential to act as a cost effective light weight alternative to battery powered carer assist products. The results of this study will be available soon, and will be posted here.
