drtbear1967
Musclechemistry Board Certified Member
SMITH MACHINE VS FREE WEIGHT SQUATS ANALOGY
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Squats and Smith Machine squats are interchangeable lower body exercises, in a way.
But even if that can be the case, both exercises display various differences starting with the bar path & foot placement, different kinematics, muscle activations and consequential adaptations.
Today I want to show you a cool analogy that allows you to understand the role of muscle stabilizers on these two different, yet not-so-different exercises.
The squat on the smith machine is like drawing a straight line with the support of a ruler. Basically, since the bar (pencil) is fixed on a vertical axis, as long as you keep the "pencil" against the ruler and draw, you'll draw a straight line.
This means that you won't need to stabilize your body as much as you would need to do in a free weight squat.
In fact, when you instead squat using a free bar, you'll have to keep the center of gravity over your mid feet, in order to maintain balance & express force vertically. This requires greater activation of muscle stabilizers:
Just like when you try and draw a "straight" line without the use of a ruler: you'll have to rely on your stabilizer skills to transfer all the force vertically and not screw it up!
"..activity of the soleus (SOL), vastus lateralis (VL), biceps femoris (BF), abdominal stabilizers (AS), upper lumbar erector spinae (ULES), and lumbo-sacral erector spinae (LSES) muscles were highest during the unstable squat and lowest with the Smith machine protocol (p < 0.05). Increased EMG activity of these muscles may be attributed to their postural and stabilization role."
https://pubmed.ncbi.nlm.nih.gov/15855681/
️
Squats and Smith Machine squats are interchangeable lower body exercises, in a way.
But even if that can be the case, both exercises display various differences starting with the bar path & foot placement, different kinematics, muscle activations and consequential adaptations.
Today I want to show you a cool analogy that allows you to understand the role of muscle stabilizers on these two different, yet not-so-different exercises.
The squat on the smith machine is like drawing a straight line with the support of a ruler. Basically, since the bar (pencil) is fixed on a vertical axis, as long as you keep the "pencil" against the ruler and draw, you'll draw a straight line.
This means that you won't need to stabilize your body as much as you would need to do in a free weight squat.
In fact, when you instead squat using a free bar, you'll have to keep the center of gravity over your mid feet, in order to maintain balance & express force vertically. This requires greater activation of muscle stabilizers:
Just like when you try and draw a "straight" line without the use of a ruler: you'll have to rely on your stabilizer skills to transfer all the force vertically and not screw it up!
"..activity of the soleus (SOL), vastus lateralis (VL), biceps femoris (BF), abdominal stabilizers (AS), upper lumbar erector spinae (ULES), and lumbo-sacral erector spinae (LSES) muscles were highest during the unstable squat and lowest with the Smith machine protocol (p < 0.05). Increased EMG activity of these muscles may be attributed to their postural and stabilization role."
https://pubmed.ncbi.nlm.nih.gov/15855681/
