Smith machines are similar in design to power cages and provide powerful, muscle mass building chest and shoulder exercises. The Smith Machine’s key feature is that the barbell is held in place at either side, so that motion is only in one controlled plane. Usually, they go straight up and down, although some Smith Machines have what is a called a reverse pitch. The uprights on this style of the machine are slightly tilted backward which can provide a biomechanically correct range of motion. The barbell glides along linear bar bearings of smooth bushings to keep every repetition steady.
Smith machines are excellent for beginning lifters to focus on chest presses and squats. The barbell on a Smith is especially safe. If you ever struggle to return the bar, you can just tilt it forward a few degrees to put it back on the catch. There is no possibility for the bar to tilt left or right, which makes the return even easier. Like a power cage with self-spotting bars, you can just slip out from underneath the bar and start again later.
In terms of customization and accessories, Smith Machines have a lot of the same options as power cages. With their large frames, there is a lot of room for accessories such as lat pulldowns, dip bars, pull up bars, etc. In fact, one Smith Machine, in particular, the Yukon Caribou II, can double as a power rack using the other set of uprights. Smith Machines can also be paired up nicely with an Olympic bench.
Yukon Fitness makes a unique smith machine that doubles as a power cage. One pair of uprights has the smith machine feature, and the other pair is designed as a normal power cage. With one machine you can take advantage of free motion barbell exercises along with the smooth, controlled action of the Yukon Carribou’s oilite bushings.
Body Solid has perfected the linear bearing smith machine for both home and commercial use.
Valor Fitness smith machines are simple but powerful.
How does bench pressing with a Smith Machine compare to using a power cage?
Both Smith Machines and traditional power cages are made with effective safety features, although smith machine barbells only require a small tilt forward to return. As for building muscles, smith machines are all about isolation and control. If your goal is to build muscle mass of specific, then the smith machine will help tremendously by targeting those muscles and allowing you to add more weight to your routine that you might otherwise. One potential downside is that supportive, stabilizer muscles will not be as engaged during the repetitions. So, while you can make good gains in muscle volume, you will not have all the functional strength that you could develop by doing squats or presses with a regular power cage. That said, there is always a trade-off with strength training equipment, so other free weights or weight machines can complement your smith machine perfectly.