Hey it’s winter- and time again to get the legs stronger for the 2012 season. Leg Press? Maybe.
One of the statements I continue to hear regarding a leg press is “why does this hurt my knees so much?”
It hurts for some very good reasons. Our bodies are designed to accept load. To work within a gravitational field. Our bodies were designed and have adapted to movements with muscle strength around working joints- to put us where we want to be on the ground. Everyday your body and brain navigate through a field of physics to move efficiently and effectively. Choosing exercises that replicate the way the body works is important.
There are many types of Leg Press you can choose, and any exercise selection should be made under the premise of (1) the exercise “affect” (or projected desired affect) on your body and (2) the safety of the exercise. When choosing a leg press exercise… they may not all be the same, and there is a reason some hurt the knee more than others.
Take a look at this leg press.
See the arrow – that’s the load vector . That red line is the load line pressing down on the angle through the body. Can you see the second line- the distance from the knee to the load line? This longer this “Moment Arm Distance ” arm- the greater the degree of torque in the joint being acted upon.. In this example- note the huge moment arm from the load line to the knee? Notice how the ankle and hip- will have much less movement from this line? Is it any wonder- your knee hurts? As a joint of motion (there are three in the leg press) It’s doing ALL the work! The torque is three and maybe four times that expressed on the ankle and hip.
Now- take a look at this leg press.
It is a different design- NOTE the articulating foot platform- the load is equally dispersed through the Hip- Knee and Ankle at all ranges in the press.
With an articulating platform-working under load with equal (or very close to equal)load dispersion is identical to how your body works under gravity.
How it was designed to work.
Choosing the right equipment at the gym is about analyzing the movement and the load to determine if it’s right for you.
No Pain no gain?
Time to THINK again… No Brain No Gain.
