Description

Design and setting This is a two-arm, parallel-group randomized trial conducted at a sports club facility.

Institutional permission for the study site has been obtained. Participants Recreational athletes who have recently begun regular physical activity and who report non-specific low back pain are enrolled. Participants provide written informed consent after receiving detailed information about the purpose of the study, the tests to be performed, and the exercise protocol. Sampling and randomization Convenience sampling is used to identify eligible participants, followed by simple random allocation to one of the two exercise groups: the core endurance exercise group or the segmental stabilization exercise group. Allocation is 1:1. Interventions Both exercise programs are delivered three days per week for six weeks. Segmental stabilization group: exercises target the transversus abdominis and lumbar multifidus and comprise stabilization exercises in the quadruped position, transversus abdominis activation exercises in the supine position with the knees flexed, lumbar multifidus activation exercises in the prone position, and standing postural control exercises involving co-activation of the transversus abdominis and lumbar multifidus.

Core endurance group: exercises are performed under the supervision of a certified physiotherapist and comprise the front plank, the side plank, and the superman plank.

Each exercise consists of 20 repetitions with a 15-second isometric hold per repetition.

The set is repeated twice, with a 3-minute rest between sets. In the front plank the participant is supported on the forearms and toes, with the shoulders aligned over the elbows and the trunk and lower limbs maintained in a straight line, producing simultaneous activation of the abdominal and paraspinal muscles. In the side plank the participant is supported on one forearm with the body held in a straight line, the shoulder aligned with the elbow and the pelvis lifted from the floor, targeting the oblique muscles. In the superman plank the participant lies prone with the arms extended overhead and simultaneously lifts the upper and lower limbs from the floor, producing trunk extension and targeting the lumbar extensor muscles. Outcome assessment Assessments are performed at baseline (week 0) and at the end of the six-week program (week 6). Demographic information including age, sex, and sports history is recorded.

Functional status and pain are assessed with the Micheli Functional Scale, dynamic balance with the Star Excursion Balance Test, and core muscle endurance with clinical endurance tests. Variables The independent variable is the type of exercise program (core endurance exercises versus segmental stabilization exercises). The dependent variables are pain level, core muscle endurance, and dynamic balance performance. Statistical analysis Normality of distribution is assessed with histogram curves and the Shapiro-Wilk test, and homogeneity of variance with the Levene test. Parametric or non-parametric tests are selected accordingly. Analyses are performed with IBM SPSS Statistics 20. Independent samples t-tests are used to compare demographic characteristics between groups. Multivariate analysis of variance is used to evaluate between-group and within-group changes, with time (baseline and post-intervention measurements) as the within-subject factor and group as the between-subject factor. Where a statistically significant difference is found, post-hoc analyses are performed with the Tukey test. Change scores between groups are also compared with independent samples t-tests.