080 - Barbell vs. Machine: Targeting Shoulders with Precision
Overhead pressing is a staple in strength programming, but not all presses are created equal. Whether you're developing tactical overhead capacity, shoulder resilience, or hypertrophy, exercise selection matters.
This study compares front vs. back barbell overhead press and barbell vs. machine overhead press, using EMG data across five upper-body muscles. The results reveal how each variation hits different targets and what that means for tactical programming.
What They Found:
Twenty-four trained males performed 6 reps at 70% of 1RM in four variations:
Front Barbell Overhead Press (FBOP)
Back Barbell Overhead Press (BBOP)
Front Machine Overhead Press (FMOP)
Back Machine Overhead Press (BMOP)
EMG data was collected for the anterior deltoid, medial deltoid, posterior deltoid, triceps brachii, and upper trapezius.
Key results:
Anterior Deltoid: Highest activation in FBOP, followed by FMOP. Back variations underperformed here.
Medial Deltoid: BBOP and BMOP led in activation, especially important for shoulder width and stability.
Posterior Deltoid: Modest activation overall, but slightly more engaged in BBOP and BMOP.
Triceps Brachii: Machine presses, especially BMOP, activated the triceps more than barbell presses.
Upper Trapezius: Free-weight presses led to significantly greater activation, especially FBOP.
What This Means:
Press selection should match the goal. The front barbell press remains king for anterior deltoid and upper trap development, ideal for tasks requiring vertical pressing power or stabilizer recruitment. In contrast, machine presses, especially from behind, enhance triceps contribution while minimizing stabilizer load, making them useful for accessory work or volume without excessive joint strain.
Back presses (especially BBOP) may emphasize the medial deltoid more, but they come with higher injury risk due to shoulder impingement potential, especially in tight or untrained populations.
Tactical Implications:
Use FBOP for strength and stabilization: Best balance of anterior delt, trap, and pressing mechanics under real-world load conditions.
Rotate machine presses for joint-friendly volume: Great for managing load during deloads, fatigue phases, or post-injury training.
Avoid BBOP in overhead-restricted populations: While BBOP targets medial delts well, the risk may outweigh the reward for many tactical lifters.
Target based on mission need: Medial deltoid dominance? Go BBOP or BMOP. Overhead load carriage prep? Stick with FBOP.
Think long-term shoulder health: Don’t just chase activation, respect mobility, posture, and load tolerance over time.
Questions To Consider:
Are you selecting press variations based on specific shoulder musculature needs?
Could rotating press variations improve long-term shoulder health and performance?
Are you over-relying on one movement pattern for overhead strength?
How do you balance stability vs. load in upper-body programming?
Is rear rack/back barbell overhead press really worth the risk in your current training population?
Paoli A, Marcolin G, Petrone N. Front vs back and barbell vs machine overhead press: an electromyographic analysis and implications for resistance training. Front Physiol. 2022;13:825880. doi:10.3389/fphys.2022.825880