# Influence of Thoracolumbar Mobility on Running Performance: A Comparative Study
## 2 Methods and Materials  
Study Design: This study employed a cross-sectional design to investigate the parameters that influence thoracolumbar mobility. All assessments were conducted using a questionnaire specifically developed for this study. Three independent groups were evaluated once to assess their current status. Following this, the three groups will be compared. This study was registered on ClinicalTrials.gov with registration number NCT06269224). Participants: This study included 105 male individuals, divided into three groups: those who had been running for the last two years, those who had been running for the last six months, and sedentary individuals. Participants were recreational runners aged 30 to 45 years who ran between fifteen to fifty km weekly; one group consisted of thirty-five runners who had been running for the last two years and the second group consisted of thirty-five runners who had been running for the last six months. The participants included were recreational runners recruited from different running groups in Ankara/Turkey. The inclusion criteria for this study consisted of three groups: (a) recreational runners who were recruited from various running groups in Ankara, Turkey, (b) individuals who had been running regularly for the past two years, and (c) a group of thirty-five sedentary individuals, identified using the Sedentary Behavior Questionnaire [18]. Exclusion criteria encompassed a history of lower extremity or lumbar-related surgery and skeletal abnormalities (i.e., scoliosis and spontaneous/congenital fusion) in the last year and a body mass index (BMI) exceeding the normal threshold of 24.5 kg/m\({}^{2}\). All participants signed informed consent, and our institutional ethical committee approved the study (GO 22/727), which was conducted according to the Declaration of Helsinki. Runners were excluded if they had skeletal abnormalities (i.e., scoliosis or spontaneous/congenital fusion) or other functional limitations when performing functional, occupational, sports or recreational activities in the past 6 months. Sample size: The sample size calculation was performed using G*Power software version 3.1 [19]. The sample size calculations were based on the effect of the modified Schober test [20]. Considering a medium effect size of 0.31, an alpha level of 0.05, and a power of 0.80, the minimum required sample size for the study was determined to be 105 participants (\(n=35\) per group). Procedures: All participants underwent demographic data collection and physical examinations. Weekly training distances (km), durations (h), and daily water consumption rates (lt) were recorded. The percentage of individuals experiencing lower extremity injuries and lower back pain within the running for the last six months group was calculated. Outcomes:  
Trunk Flexibility: The measurement of trunk flexibility (rotation, lateral flexion, and extension) was performed using a measuring tape. For trunk rotation, the participant stood facing the wall, bringing the front of their body close to the wall, with the anterior part of the pelvis fixed against it. While rotating the torso, the distance between the acromion and the wall was measured. Lateral flexion was assessed by measuring the distance from a fixed point to the lateral edge of the body as it bends to the side. Extension was evaluated by measuring the distance between key anatomical points as the participant bends backward. The distance from the sternal notch to the wall was measured and recorded in centimeters (cm) [21]. Trunk ROM: The ROM values were evaluated using a goniometer. The measurement of trunk flexion, lateral flexion, and extension was performed using a goniometer. For trunk flexion, the participant bent forward, and the goniometer was placed at the lumbar spine or hip joint to measure the angle between the torso and the thighs.