Using external momentum during resistance training does not appear to raise the risk of injury in beginners over 8 weeks, but the study was too short and too small to determine risks over longer...
Mechanism
Synthesis from 1 study
When people who aren't used to lifting weights use a little swing to help move the weight, the force doesn't hit their muscles and tendons as hard or suddenly — it's more like a gentle push than a sharp jerk. This helps prevent immediate injuries, but we still don't know if small, repeated stresses...
Most probable mechanism
When someone uses a little extra swing to lift a weight, the force gets spread out more smoothly across muscles and tendons instead of hitting them all at once, which helps avoid sudden tears or strains — especially in people who haven’t trained before.
External momentum reduces the rate of force application during the concentric phase of resistance movement, distributing mechanical load over a longer time interval across muscle-tendon units
Slower force transmission decreases peak tensile stress on connective tissues, reducing the likelihood of microtrauma that could lead to acute injury
Neuromuscular control in untrained individuals adapts to the altered force profile, allowing coordinated muscle activation that buffers joint and tendon loading
Evidence from Studies
Supporting (1)
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Do Cheaters Prosper? Effect of Externally Supplied Momentum During Resistance Training on Measures of Upper Body Muscle Hypertrophy
Contradicting (0)
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Gold Standard Evidence Needed
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