Fig. 4

a–c Effect of duration of CHP stimulation on early osteogenic gene expression at frequencies of 0.5 Hz (2 and 4 h) and 2 Hz (1 and 2 h). N = 2, n = 3–4. *p < 0.05, ***p < 0.001 compared to static control; ^#p < 0.05, ^##p < 0.01, ^###p < 0.001 for magnitude effect