You don’t need any equipment and you’ll get great shaped legs and a toned behind ready for summer if you do enough of them (and you do them right)!
You must ensure you keep proper form when you do your lunges to prevent any strain on your joints.
When you’ve got your form bang on, you can modify lunge in many ways to get the best results.
You can try reverse lunge (stepping backwards), prisoner lunges (hands behind head) and jump lunges (with a bounce in between swapping legs).
You can also focus on your upper body at the same time by incorporating a bicep curl with dumbbells as you lunge.
If you experience any pain, make sure you don’t stride too far forward and keep within your range of mobility. You’ll soon start to see results as long as you keep to the correct form.
I love a good lunge, but also have knees that are prone to injury. So I don't do too many and probably do everything this article says too.
I would also add 'wear your trainers' to protect your knees. Not quite sure why this is but it seems to work for me.
I always try to 'take the strain' in my buttocks, rather than my knees. This seems to help avoid any straining feelings.