Fig. 5

The correlations between different estimates of inter-muscular synchronization. a Linear regression between the number of synchronized muscles and the pooled coherence / pool-averaged coherence level at tremor frequency detected from each subject. The pool-averaged coherence at tremor frequency shows fine linear relationship with the number of synchronized muscles, while the pooled coherence doesn’t. b Linear regression between the number of synchronized muscles and the pooled coherence / pool-averaged coherence level at double tremor frequency. The pool-averaged coherence at double tremor frequency also shows significant linear relationship with the number of synchronized muscles, while the pooled coherence doesn’t