Can lack of exercise or lack of walking cause rhabdomyolysis?

Typically not. Rhabdomyolyisis is caused by muscle damage, not lack of use. Lack of use will result in muscle atrophy, but not in the dangers of muscle breakdown.Risk factors include the following: alcoholism, physical injuries, drugs, especially cocaine, amphetamines, statins, heroin, or pcp, heatstroke, low phosphate, severe exertion, etc.