Resting weight on crutch
We think of a crutch as a simple mobility aid but a new crutch being developed at the University of Southampton may be able to provide a lot more useful information for doctors and patients. Professor Neil White, from the University's School of Electronics and Computer Science, says his personal interest began about two years ago, when his son got injured playing football, and he was chatting with knee surgeons and physiotherapists at the hospital. ‘One of the things that came out of the conversations,’ says White, ‘is that sometimes it’s useful if the patient can put some partial weight bearing on the leg. Patients are told how to use them at hospitals, for example to put fifty percent of the weight bearing on the leg but by the time they’ve got home they’ve forgotten what fifty percent is, and they are either putting on too much weight or too little.’

Measuring stride pattern
Professor White’s research area is sensor technology, which covers a broad field from devices themselves to sensor systems. Working with Dr Geoff Merrett, a colleague in the Department, and Georgina Hallett, a physiotherapist at Southampton Hospital, he began developing a crutch that could indicate to a patient the amount of weight they are putting on their leg. ‘Also because it’s quite easy to do so,’ he explains, ‘we put some sensors in that measure the actual movement of the crutches and the angle that is cutting the ground.’ Physiotherapists believe that a good stride pattern and gait can help recovery. And it was also suggested that the ‘grip force’ on the handle would be useful to measure because occasionally patients grip the handle incorrectly which can also cause potential problems.”

Wireless transmission
All the measurements are transmitted wirelessly to a laptop were the physiotherapist can assess the information. ‘What we’d like to do,’ says White, ‘is embed some memory within the crutches so you can give them to a patient, who can have them at home, then when they went back to the hospital for a check up, the physiotherapist has actually got all the data from a week or two weeks’ worth of using the crutches.’ As they develop the technology it could prove particularly beneficial to elderly patients who could be monitored in case they fall at home.