Figure 5

Spinal manipulation did not alter the amplitude of the motor evoked potential (left) recorded from the erector spinae muscles in individuals who exhibited an audible response in response to spinal manipulation or in those who did not. Interestingly, spinal manipulation did reduce the amplitude of the short-latency stretch reflex in individuals who exhibited an audible response in response to spinal manipulation when compared to those who did not (*time × group interaction: p = 0.05; η² = 0.20).