Please avoid smith machines as much as possible.
They cancel utilization of stabilizer muscles and do not allow the body to work in the normal three-dimensional plane.
Source:- http://ezinearticles.com/?Squat-Rack...ine&id=1807173Originally Posted by Daniel EvansThe squat rack is a free standing frame which allows a person to load and unload a barbell from an elevated position.
The power cage provides the same but being composes of 4 posts it seat catcher pins which allow the trainee to lift safely alone. The catching pins are set a few inches below the bottom position of the lift. In the event of a fail the bar is bailed and dropped onto the catchers.
Some squat racks feature catchers also but are uncommon.
The Smith Machine looks similar to the Power Rack but features a bar fixed to vertical rails. It is of utmost importance to recognise the difference between the Smith Machine and a power rack since each dictates a very different training style.
The power rack provides:
- A method of Loading
- A method of unloading
- A failsafe.
A Smith machine provides the same but dictates movement pattern and it is this which renders the piece of equipment useless to anyone who wishes to train effectively. Since the bar on the Smith Machine is guided by vertical rails it does not allow for natural three dimensional movement. This is more of a problem that people might assume.
As a trainee moves a bar through the range of motion using free weights their body requires freedom of movement to make micro adjustments which include the ways in which joints move and the ways in which muscles contract. This is inclusive of small stabilizer muscles which require freedom to develop to do the job they are intended to do; stabilizing the body with or without an external load. This is regarded as functional training since it has potential carryover into the real world.
Restricting the body to work within a two dimensional plane can create stress upon the joints and programs incorrect motor pattern. "Motor pattern" is a learning process which the body initiates to perform a movement more efficiently. As limbs move signals are passed through the peripheral nervous system to the central nervous system (through the spine) to the brain. The brain then signals to the limbs through the same path how to change their accordingly through muscle contraction. It's an unconscious process but it's an essential factor when learning how to perform lifts correctly.
A trainee who places faith in a Smith Machine pushing an external load on vertical rails will respond to become more efficient at moving in this manner regardless if it has potential detrimental effects to other parts of the organism. An example might be the knees which can suffer due to restrictions in movement and limited load handled by muscle tissue.
Lifting in the Smith Machine teaches how to lift in the Smith Machine - nothing more. It has very little carryover to the free weight alternative and needless to say is unsuited to any trainee - particularly beginners.
These principles also apply to most pieces of equipment that dictate a fixed plane of motion. An external load lifted in a real life circumstance will rarely be attached to rails.
Leave the lifting with rails to forklift trucks!
If you're going to use machines, please make sure it's AFTER you use the free weights unless you're recovering from some sort of injury.