TETRAGRIP II - Usability Trial of an FES Orthosis for People With Tetraplegia.

TETRAGRIP II - Usability Trial of an FES Orthosis for People With Tetraplegia.

Functional Electrical Stimulation is an established technique in which small electrical impulses are used to cause a contraction in muscles and thereby enable movement, in people with neurological or musculoskeletal problems who are unable to undertake those movements themselves. People with spinal cord injuries of the neck at C5, C6 and C7 account for 35% of all spinal cord injuries. Despite this, there is only one commercial FES (Functional Electrical Stimulation) based orthosis currently available. Even that has limitations in that it as it has a single size rigid exoskeleton it does not fit all people who could benefit and also due to its rigidity it does not allow people with lower injuries to utilise any remaining tenodesis grip. As a result, it is not widely used within the spinal injured communities. Therefore what is required is a more flexible system that can benefit a larger number of people whilst still being affordable within the constraints of the NHS. A previous INSPIRE funded project, TETRAGRIP I demonstrated that a surface FES system controlled by an inertial sensor, measuring movement of the opposite shoulder, could meet this specification and was successfully tried on two people with tetraplegia. What is now required is a more detailed study in which the principle components of that system are incorporated into a practical device suitable for use at home without clinical supervision. It is therefore proposed to develop and build such a system and to conduct extended home based trials in three people with tetraplegia.

Inclusion Criteria:

• Have a spinal cord injury that has resulted in tetraplegia affecting hand function.
• Minimal spasticity of wrist muscle.
• Able to do shoulder elevation.
• Upper limb passive range of motion should be within normal limit.
• Age group: 18 years and above.
• Able to understand and comply with assessment procedures.
• Able to give informed consent.
• Able to produce a muscle contraction using electrical stimulation in sufficient muscles produce a functional grip.

Exclusion Criteria:

• Using a cardiac pacemaker, defibrillator or other sensitive implanted device.
• Pregnant or planning to become pregnant over the course of the study.
• A history of poorly controlled epilepsy.
• If there is malignancy on the hand or arm.
• If younger than 18
• Severe contracture of wrist and finger joints.
• Painful shoulder.
• Suffering from significant autonomic dysreflexia in response to FES.