youve seen guys injure themselves while doing squats?crunches work for me, although you hafto do more of them, they work.... I usually do 60 uppers, 60 lowers, 30 each of side abdominals. and I can do em pretty fast too.
squats are only a high risk injury when done with bad form. The reason why so many people injure themselves is because the average gym user does not actually know that much about safe or effective weight training. In my own experience high rep (60+) exercises generally result in more injuries than low rep ones (10 or less) simply due to the fatigue factor (people's often goes bad as they tire) and long term stress on the body.as for developing your abs via situps, this is just a guess but has your body fat % dropped as well over the past year? in most cases showing a 6 pack is more a result of a low body fat that developing ab muscles. I train with a quite a few pro fighters who mostly have highly defined 6 packs despite never doing situps except for warm up routines. This is mainly because of them maintaining a low bodyfat % for fighting in lower weight classes.abs being primarily a stabiliser muscle are developed more when they are used to stablise during heavy lifting movements than they do from just high rep situp routines. a lot of non-heavyweight olympic and power lifters actually have huge ab muscles (not just defined ones) as a result of their main lifting routines which do not really focus on abs much. thats not to say you can't get strong abs from situps, but I feel there are much easier ways to achieve a strong stomach than to dedicate a specialised workout to it.