I'm in my early 50s and have had two knee operations in two years due to excess weight. I now walk with a stick. I know my weight is to blame, but I am in a vicious circle of being unable to exercise to help shift the weight. What can I do?

It's vital that you reduce the pressure on your knees to help claim back independence from your stick. The more you use a stick, the more you can come to depend on it, further weakening the supportive muscles around the knee. Ditching the stick will provide a huge psychological boost, while the ability to put more work through your legs is essential if you're going to shift weight. This will not be a quick fix, so be realistic in terms of timescale and rate of progression.

My first suggestion involves technique, the second kit. For technique, try the full glass trick - imagine that you have a full glass of water on each hip. As you walk, try to keep each glass full by minimising hip swing. To achieve this, pull up through your belly button and extend through your spine. For kit, try a pair of MBT trainers (mbt-uk.com), which help postural alignment and reduce joint pressure.

The combination of the two should naturally reduce excessive hip sway, minimise the forces through lower limbs and banish stick leaning. When you begin, respect the time your body needs to adapt, wear your MBTs for short bouts and practise the full glass trick over shorter distances. If you're not bashful, ask a friend to walk slightly behind you to offer feedback on how much you are swaying your hips.

Joanna Hall is a fitness expert (joannahall.com). Send your exercise questions to Weekend, 119 Farringdon Road, London EC1R 3ER (weekend@theguardian.com).