i don't think this is an appropriate title"top ten injury causing machines" any exercise with machines or free weight done with a poor form or with bad equipment can cause injury. machines like the smith machine are not for beginners , who can also injure themselves with barbell squats and deadlifts...
i use the smith machine for calf raises and presses all the time and it is very safe if used the right way. leg extensions???? i don't see why it causes injury your legs are free to move or rotate without restrictions. cable rows? i don't see why it is not safe at all it is much safer than barbbell rows. declined bench also ...and most of the rest....
Now personally i don't like the pec-dec or the lateral raises machines which can put some stress on joints, but these machines must be used appropriately, they are to be used with very light weight and slow movements to get the benefits. one of the most devastating exercise is the dead lift,the front shoulder barbbell raises, the bench press, the military press and the squats if done with poor form.
CONCLUSIONS: injury is not because of the machines or equipment(if the equipment and machines are of good quality and design) injury comes from poor training techniques: poor form in order to lift heavier weights, poor judgement, and poor preparation and warm up.
The problem is for beginners that they are too much affected by pros who figure on magazines and are focused on the heavy weights etc.... where in fact most of these pros do not know how to train. i used myself heavy weights and cheating for years , now i am 51 and i am focusing on pure form and the results are better than ever, Who said that test levels are low at 50 and you can't build muscles naturally?????????