To those who have experienced claims for exoskeletons in recent years it is worth noting that a recently published study from the Netherlands essentially describes itself as the first study charting the use of exoskeletons in a non-clinical or gym setting: Exoskeleton Home and Community Use In People With Complete Spinal Cord Injury.
It is a very small study (n=14) and it is worth noting the considerable limitations which existed in terms of finding participants for the study:
- Motor complete SCI AIS A or B
- Levels: Thoracic 1 – Lumbar 1
- More than 6 months post injury
- Height between 1.6 – 1.9 metres
- Weight less than 100 kgs
- No restricted range of motion at hip, knee and ankle joints
- No severe spasticity
- An ability to control crutches
- An inability to transfer from chair to wheelchair without external aids
- No co-morbidity that could interfere with motor learning
- No one with an increased risk of osteoporosis or fractures in the previous two years
In addition participants were required to attend and pass an 8 week exoskeleton training course (together with having a buddy available at home when using the device).
The device chosen for the study was the ReWalk Personal 6.0. This is a device with which I am very familiar. Together with the Indego from Parker Hannifin it is one of only two devices to have FDA approval for use in both a clinical setting and in the home / community. We have talked about the Indego many times: Achilleas Dorotheou (Parker Hannifin's Head of Human Motion) did a fantastic presentation at one of DWF's conferences some years ago and I also attended its UK launch.
Once they had passed all the tests the participants were loaned a device and had no restrictions placed on them for their use of it over a period of 2 – 3 weeks. The number of steps taken in the device was recorded from the device's software and participants also had to fill in a daily questionnaire for those days that they used it. It is worth reading the complete study to see how it was designed and the various measures adopted. Nevertheless a few things stood out to me:
- Median exoskeleton use was 9 out of 16 days
- Median range was 3,226 steps
- Median active time 46 minutes
- Median distance covered 243 metres
The subject reported primary use was individual exercise (74% of all sessions) and it was noticeable that 48% of all sessions took place outdoors with an additional 27% on level ground in either a gym or car park. Only 6% of sessions were exclusively at home. I speculate but this suggests to me that participants were mainly trying to recreate rehab / training effects rather than use it as personal assistive device for ADL's. Indeed there is a study Exoskeletons for Personal Use After Spinal Cord Injury which suggests that exoskeletons have low potential as an assistive device for supporting daily activities and, given the current state of development, this is hardly surprising when one considers that they are operated with the user's upper limbs occupied by crutches and a buddy walking alongside.
I am reminded of another presenter at one of DWF's conferences: the amazing Martyn Ashton (if there is anyone left who hasn't seen this before and it has 13,000,000 views on YouTube so I doubt it [!] go and check out the seminal Road Bike Party) who, after trialling an exoskeleton and marvelling in it as a piece of technology, came back to the conclusion that a wheelchair was always going to be his go-to device.
Participants most frequently scored the ReWalk's weight (27 kgs) effectiveness, safety and ease of use as 'dissatisfied' whilst at the same time rating those features as important. One fall was recorded together with one device error. Encouragingly 5 participants reported health benefits but this was balanced out by 5 participants reporting negative health related effects.
Clearly these devices aren't for everyone and, whilst it is difficult to draw too many conclusions from such a small study, as we sit here today it seems clear to me that use in the home / community presents too many challenges. For users who fit the profile they have their place in a controlled rehab setting but beyond that I don't think that the technology has evolved far enough. That said it is still very early days in the development cycle: the Indego already weighs less than the ReWalk and as we see developments in battery technology I would imagine that weight could be reduced dramatically.
Who knows what the future will bring but it is exciting to keep an eye on the developments in this area of technology. Hopefully the manufacturers continue to invest and improve these devices because it would be amazing if we could reach a point where the user was safe and truly independent.
If you have any enquiries about this topic, please contact Ian Slater.