Fig. 3

Changes in pain free grip strength (PFGS) over time. a The sensory threshold at which point participants report the onset of pain during gripping, before (pre) and after (post) treatment with manual acupuncture (dotted line) or electroacupuncture (solid line). There was no consistent trend observed for either type of acupuncture, and no difference between the two treatment groups. b The change in PFGS from baseline is indicated for all participants (both treatment groups), with positive numbers indicating an improved (raised) pain threshold. Unexpectedly and for unknown reasons, PFGS improved during the 72-h follow-up period. Asterisk indicates a statistically significant improvement in PFGS compared to baseline, but this occurred too late in the experiment to be confidently attributed to the effects of acupuncture. N = 21, 20 and 20 for the three time points shown. Error bars represent 95% CI