Sample sizeThe sample size was determined from the pilot study, whereby 5 subjects were used in each group. The difference in the thickness of the semispinalis capitis muscle between maximum and minimumchange variation was determined. The mean difference was 0.17 cm and standard deviation was determined to be 0.12 cm. Using these data, for desired power of 90% and with 0.10 type I error, the sample size was generated as 15 subjects in each group to determine the difference among the 3 groups. However, taking into consideration the possible drop-outs, 20 subjects were included in each study group. Sealed envelopes were used, which were opened immediately prior to intervention after the participant consented to be a part of the study. They were then randomized using the sealed envelope method and divided into 3 groups of 20 patients.Sixty envelopes were used and equally numbered with group names 1 (Pilates), 2 (yoga), and 3 (isometric). The patients were asked to choose 1 of these sealed envelopes. The CONSORT(Consolidated Standards of Reporting Trials) flow diagram of the study is shown in Fig. 3