Introduction: Low back pain is a musculoskeletal disorder that is associated with symptoms such as pain, limitation of joint range and postural problems in athletes. Postural control is a key factor in disciplines with high biomechanical demands, such as rhythmic gymnastics. In addition, the potential influence of occlusal splints on body posture has been discussed, although evidence remains inconclusive. Methods: The study design is a randomized controlled clinical trial with a minimum of 35 elite gymnasts with back pain. Two postural treatments will be implemented, Mezieres Method and Isostretching, to verify whether there is improvement in low back pain in gymnasts and to compare both procedures. Postural variables will also allow exploratory analysis of factors potentially associated with postural regulation, including the possible influence of occlusal-byte use. Discussion: This trial could generate a greater understanding of the importance of posture related to low back pain and its possible treatments. It may also contribute to clarifying the relationship between postural therapeutic approaches and other factors influencing postural control.

A randomized controlled clinical trial with two groups (intervention and placebo) will be implemented. The intervention group will receive the Mezieres technique as postural treatment, while the placebo group will perform a total of six Isostretching positions. Both interventions will consist of 30-minute sessions delivered twice weekly over a 12-week period. All treatments will be administered by the same certified therapist with at least five years of experience in postural therapy. Outcome measurements will be obtained immediately after the first session, and at 2, 6, and 12 weeks. Assessments will be conducted by a blinded researcher who will not participate in the treatments and who has prior experience in postural evaluation. Postural measurements will additionally permit exploratory analyses of factors potentially influencing postural regulation, including the possible impact of occlusal-byte use.

Inclusion Criteria:

• Elite gymnastic athletes with low back pain
• Active participation in the national competition
• Practice at least three times a week for 60 minutes
• Minimum training time of 7 hours a week

Exclusion Criteria:

• Gymnast whom suffer from chronic disease or acute musculoskeletal injury
• Herniated disc
• Spondylolisthesis