The goal of this clinical trial is to evaluate the clinical effectiveness of proprioceptive neuromuscular facilitation (PNF) combined with spiral muscle chain training in improving spinal function and posture in adolescents aged 13 to 18 years with spinal curvature abnormalities.

The main questions it aims to answer are:

Does exercise-based intervention improve trunk inclination angle, kyphotic angle, and body balance parameters in adolescents with spinal curvature abnormalities?

Does the combined intervention improve spinal mobility and paraspinal muscle endurance compared with single-intervention approaches?

Does the combined intervention lead to favorable changes in surface electromyography (sEMG) indicators of the paraspinal muscles?

Researchers will compare a PNF therapy group, a spiral muscle chain training group, and a combined PNF plus spiral muscle chain training group to assess differences in trunk inclination angle, kyphotic angle, spinal mobility, paraspinal muscle endurance, and neuromuscular activation outcomes. Body mass index, fat-to-muscle ratio, and other body-composition-related indicators will be analyzed as exploratory post hoc outcomes.

Participants will:

Be assigned to one of three intervention groups: PNF therapy alone, spiral muscle chain training alone, or combined PNF plus spiral muscle chain training.

Participate in supervised exercise training sessions three times per week for 12 weeks.

Undergo pre- and post-intervention assessments, including body composition testing, electronic spinal measurements, and surface electromyography testing.

Inclusion Criteria:

• Aged 13 to 18 years
• Newly diagnosed with no prior treatment and meeting the diagnostic criteria for spinal curvature abnormalities
• Scoliosis or coronal spinal curvature abnormality determined by poor posture and angle of trunk inclination or angle of trunk rotation of 5° or greater
• Anterior-posterior spinal curvature abnormality determined by poor posture or abnormal spinal side-view assessment, including kyphotic angle less than 20° or greater than 40°
• No prior brace treatment
• No history of spinal surgery
• Able to complete proprioceptive neuromuscular facilitation therapy, spiral muscle chain training, or combined exercise training as required
• Written informed consent obtained from participants and their parents or legal guardians

Exclusion Criteria:

• Menstruating females at the time of assessment
• Metal implants
• History of brace use or prior treatment for spinal curvature abnormalities
• Severe scoliosis, defined as angle of trunk inclination or angle of trunk rotation greater than 13°
• Congenital spinal curvature abnormality
• Neuromuscular disorders
• Respiratory dysfunction
• Any contraindication to exercise
• Any trauma within the previous 6 months
• Any accompanying neurological, rheumatological, or mental health problems

Individual participant data (IPD) will not be shared because the study involves minors, and the data include sensitive health information related to spinal posture and neuromuscular function. According to the approved ethics protocol, strict measures are required to protect participants' privacy and confidentiality. Although all data are de-identified, sharing IPD may still pose a potential risk of re-identification. Therefore, IPD will not be made publicly available in order to ensure compliance with ethical requirements and data protection regulations.