This idea of having a handbrake on your muscles may actually be more real than you think. Not a handbrake in your muscles, but a handbrake in your brain which is what controls your muscles and tells them to contract.
Studies have shown that chiropractic adjustments can make you stronger
One study reported in a group of students who received chiropractic care, that they were actually able to produce 16% more force in their leg muscle after a chiropractor had gently checked and adjusted any dysfunctional spinal segments, or what chiropractors call vertebral subluxations.