Leg extentions

[waunlee]

Hello all,
This is my first post so be patient with me. I am a certified fitness trainer at a local gym. The owners here always show new members the leg extention machine as part of their initial fitness program. I have heard and read that this exercise is not safe on the knees. I never do them myself. What is your take on this?

[Axis]

8. Leg (knee) extensions. Leg extensions are one of the most popular exercises for strengthening the quadriceps femoris muscle, however, doing leg extensions when the thigh is immobilized on the seat of a bench is potentially dangerous because of the pressure built up in the knee joint. When only the shin is in motion, the forces multiply greatly in the knee joint. When both the thigh and shin are free to move as in the squat or when doing the exercise with rubber tubing as in the Active Cords set, the pressure is less, making the exercise much safer. When you are locked into a seated position and then straighten the leg, the internal forces are so great that damage can occur to the connective tissue and especially the ligaments supporting the knee joint. For greater safety, and equal effectiveness, do the squat or knee extensions with Active Cords.

source

[Simon.]

What's an 'active cord' ?

[Axis]

Originally posted by Simon.:
What's an 'active cord' ?

Just a brand of rubber tubing, I think.

[Jean-Paul]

Hm, strange. You're from LR, and your profile says you work for JP Fitness, but I don't advocate leg extensions there, so I can't figure out who this is. Curiosity is killing me here!

In answer to your question, they aren't necessarily "dangerous", they're just not very effective. I usually tell people that if they have enough energy to do leg extensions then they didn't work hard enough on squats or lunges, which is my way of saying "get your ass back under that squat rack!" ... "and don't let me catch you doing any curls either!"

[waunlee]

Thanks for the feedback so quickly. Now, I have a little more ammunition for the local "gurus" at the gym. You guys are great!!!

Just for the record and to save my neck: JP Fitness is not a "local gym", it is a Professional Wellness and Personal Training Center. And, one of the best I have ever had the pleasure, no, the honor of working at (gettin kinda deep in here). I was talking about the other guys. Whole different animal.

[Jean-Paul]

Nice save! BTW, if you want to get a working vocab a little quicker in here for all the various workout programs people post about, here is a good place to start.

Is this Leo?