I’ve gone down with Canvasser’s Heel.   Well, the doctor called it plantar fasciitis: her first question to me after I had described the symptoms were, ‘Does your job involve a lot of standing and walking?’

The NHS defines it as ‘excessive, constant abnormal pulling and stretching of the fibrous bands that support the arch, [which] causes the heel bone to become inflamed and painful. This constant irritation can sometimes lead to a heel spur (bony growth) forming on the bottom of the heel bone.  The patient usually complains of pain with the first step in the morning, some relief following activity, but the pain returning after extended amounts of time standing or walking.’

I’d thought I’d bruised my heel somehow, and had gone on canvassing (and limping) over several weekends, until it was clearly getting worse rather than better.  The cure starts with icepacks applied, then rest, physiotherapy, walking gently, and wearing well-padded shoes.

This used, apparently, to be called ‘Policeman’s Heel’.  Brian Paddick hadn’t heard of it, and the policeman I spoke to in Liverpool during our Spring conference only said that ‘we spend most of our time sitting in cars these days’.  But the officer on duty outside the Commons as I left last Thursday said he’d suffered from it: too much walking around on hard pavements, made worse by standing for long periods on street corners.  Road runners often suffer from this, too, I’m told.

So what should the dedicated Liberal activist do to avoid succumbing to this in the course of an election campaign?  Wear comfortable lace-up shoes with thick soles and heels, for a start: Clark’s shoes, or trainers, are much better than thin-soled shoes.  Sit down from time to time; twiddle your toes, flex your feet by going up on your toes and back every now and again.  Put padded insoles in and arch supports, if that helps more.  Think about the risks of spending too long on concrete and tarmac; walk on the grass when you can.

There are other injuries from campaigning, of course. Helen, my wife, has damaged her fingers several times from being caught in letter-boxes while delivering leaflets.  Ollie Grender’s recommendation to avoid this is to take a wooden spatula out with you, fold the leaflet round it, and push that through the letter-box: proof against dogs indoors as well as against sharp or sprung openings.  A Labour colleague in the Lords tells me she uses a wooden spoon in the same way.  This is too late for Helen’s trigger tendon, or for the joint on her middle finger; but it may help others who haven’t clocked up as many doorsteps since she first helped her father in the 1955 election.

So I will be spending more time phone canvassing in this election than I’d intended.  But I’m aware that there’s nothing as good as the doorstep conversation for worthwhile interaction with voters.

One advantage of a Spring campaign is that the weather should be good, and in the evenings and at weekends many people should be in their gardens, and willing to chat.  Others have probably encountered heavy disillusionment with politics as a whole, as we have – ‘You’re all the same, but I might vote for XXX because at least he’s a good MP’ – but a few minutes of conversation often softens their jaundiced views.

This is an election in which local contests, and local views of the qualities of candidates and sitting MPs, looks likely to count far more than in election contests a generation ago.  Voter perception of which candidates are putting up a fight, and which are purely on paper, will also count a lot.  Pounding the pavements in target seats will make a vital difference.  So get out there and enjoy it, though without pounding the pavements too hard.  I’m only sorry that my doctor has forbidden me to join you!

* William Wallace is LibDem peer, a former vice-chair of the Federal Policy Committee and convenor of the party's 1997 manifesto team.