Sample size
According to the data of a randomised pilot study which
involved 10 patients, the effect size based on the Functional
Rating Scale (FRI) was calculated to be 1.83. Since
the number of patients in the pilot study was few, we calculated
the sample size for the current study using an
effect size of 0.8. Considering the results of our previous
article [18] and the results obtained from the pilot study
we expect ultrasound to be more effective and have chosen
a one-sided test to calculate the sample size. Assuming
alpha and power to be 0.05 and 0.8, in a one-tailed test the