Leg extensions

[zlightning]

Ok I read that they are bad for you knee joints does anyone know where they came up with that idea? I'm not saying they are or not just wondering if their claim is justified. Read it on AST's site. If it's true what other exercises are there for the quads?

[Jean-Paul]

Hm... they don't bother my knees, but I honestly rarely do them anymore. They probably also tell you never to go beyond 90 degrees on a squat, yet every notable strength coach out there tells you to get down in the basement.

It is almost irrelevant anyway... They shouldn't be the cornerstone of a serious leg program anyway. Just a nice finisher. Squats and Deads are still king!

[fitone]

Knee flexsion machine the proper terminolgy. You actually flexing the knee joint and not extending it. On your question though a lot of physical therapist uses this exercise to strengthen the muscle around the knee joint. So if they are using it to re habing people w/ knee problems I would think that its a safe machine for your knees.

Although, they aren't Squats or Deadlifts as JP said and that should be the cornerstone of any leg work-out.

In Health,

Silas Chen

[brian]

I have torn my medial meniscus four times (left knee three times). In the early 80s and mid-90s, the PT did entail leg extensions, both on a Nautilus style machine and a Cybex (eccentric and concentric resistance).

My last surgery was around Xmas. The recent PT DID NOT entail leg extensions, as the exercise was seen as potentially damaging (too much shearing stress on the Patella), and not as sport specific as squats and lunges.

Much of what I have been reading since my surgery has focused on stability, proprioception, and sport specific movement.

I am a Newbie to this forum, so I am going to challenge those who are into resistance training for body-building type goals. However, if you are an athlete, there is a ton of material out there arguing against training like a body builder. Leg extensions fall into the "body builder" category.

[Bill Hartman]

If I may offer a physical therapist's point of view...

First, no exercise is ever contraindicated for everyone or for every situation.

However, the reason knee extension exercises get a bad rap is related to closed chain mechanics (essentially the foot on the ground with some exceptions) and open chain mechanics (essentially the foot off the ground with some exceptions).

In a knee extension exercise on a leg extension machine (open chain) there is greater compression of the patella (knee cap) on the femur and also greater anterior tibial (tibia = shin bone)translation or shear at the knee joint due to a reduced recruitment of the knee flexors (hamstrings, gastroc, popliteus). If you have or have had any form of patello-femoral pain, chondromalacia patellae, anterior knee pain, or internal derangement of the knee (meniscus tear, ligament sprain or tear, chondral defect, etc.), the open chain knee extension is typically contraindicated as it commonly aggrevates the condition.

This is also quite common in cases of machine based hack squats and squats on a smith machine as the hamstring involvement is also reduced.

In the closed chain exercises which involve knee extension like a regular barbell squat, leg press (because of the greater hip extension moment the hamstrings are still strongly involved), lunge, step-up, etc. the patellar compression and tibial shear forces are much less as the hamstrings are co-contracting throughout the movement. That is why in rehabilitation situations, such as post surgery, therapists typically stick with closed chain exercises. They are deemed safer and more functional as the knee rarely functions in the open chain manner.

Also keep in mind that shear forces and patellar compression increase with the depth of the squat, so if you are symptomatic of some form of knee pain, deep squats may also be contraindicated. If you are asymptomatic, then ass-to-the-grass squatting should not be an issue if your flexiblity will allow proper technique and you follow some form of periodized training plan.

Hope that helps

Bill Hartman

[zlightning]

Originally posted by Bill Hartman:
meniscus tear

Thats what I have had this is the 3rd time. Yes it did help. Anyone know how long I shouldn't lift with the legs? I'm sure my doc will know I just don't remember how long I was out the frist two times.