This study was aimed to compare the effects of three soft tissue treatments in different parts of the myofascial lateral line (LL) on the hip adduction range of motion (ROM). [Participants and Methods] Thirty university students received Ergon ® instrument-assisted soft tissue mobilization (IASTM) treatment, foam rolling, and static stretching on the upper or lower part of the LL on the side of their non-dominant lower limb, while the other body side served as control. The participants received one treatment per week for six weeks with a simultaneous pre-and post-therapy assessment of their hip adduction ROM. [Results] The hip adduction ROM was improved on the intervention side in all experimental groups. The gains were more significant in groups that received the Ergon treatment. All Ergon interventions, as well as foam rolling on the upper part of the LL, led to the greatest hip adduction ROM improvement compared to the control side. No differences were observed between the Ergon groups. [Conclusion] The findings suggest that the implementation of Ergon IASTM, foam rolling, and stretching can produce positive effects on the hip ROM. The Ergon Technique is more effective compared to foam rolling and stretching, irrespective of the application site.