Not sure. Not a doctor but if you do I certainly wouldn't put a lot of weight on. That being said when used properly I think this is a kinder machine than most. I can easily max out most of these machines for a few reps and I don't consider myself to be very strong I'm about 150 pounds 5 feet 9, 28 year old male. This exercise is riskier for the knees than anywhere else I'd say. Get advice from your doctor/physiotherapist. I have a dodgy ankle because I tore a ligament in it years ago but I've never had any problems with this machine it's a personal favourite to end my workouts on along with leg press because usually I check my messages and emails while sitting and cooling down a little.
Who manufactures this machine?
You want your head to rest on the pad. Your spine will thank you later
Can you do this exercises if you have achilles tendonitis
Not sure. Not a doctor but if you do I certainly wouldn't put a lot of weight on. That being said when used properly I think this is a kinder machine than most. I can easily max out most of these machines for a few reps and I don't consider myself to be very strong I'm about 150 pounds 5 feet 9, 28 year old male. This exercise is riskier for the knees than anywhere else I'd say. Get advice from your doctor/physiotherapist. I have a dodgy ankle because I tore a ligament in it years ago but I've never had any problems with this machine it's a personal favourite to end my workouts on along with leg press because usually I check my messages and emails while sitting and cooling down a little.