When it comes to the wear and tear of a joint leading to osteoarthritis, I would have to say doing lunges would fall into that same category as squats would considering it is a weight bearing exercise with a large range of motion performed by the knee joint. A key to avoiding knee injury when performing static or walking lunges is to ensure that the front knee is NEVER sticking out front beyond the toes as it will lead to knee injury. As well, ensure the back foot is straight back ie. the heel is not rotated inwards or outwards, but rather in line with the rest of the body.
Apparently the largest contributing factor to knee pain is due to a muscle injury or imbalance of the thigh muscles (or quadriceps) as they have four heads that insert into and stabilize the knee. Keeping these muscles strong helps to avoid knee problems, however it seems that many exercises for these muscles involve wear and tear of the knee. Is it best not to exercise the legs at all then? Absolutely not!
Stretching and strengthening exercises help maintain healthy cartilage, increase a joint's range of motion and strengthen surrounding muscles which allows them to better absorb shock. These types of exercises help to prevent and are also used in the treatment of osteoporosis. Good low-impact examples of these exercises would be yoga and the use of resistance bands.
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