Mechanical low back pain is a common problem among novice runners, often caused by poor control of the lumbopelvic region and weak core stability. Coordinated Locomotor Training is a neuromotor exercise approach that improves the coordination of arm and leg movements while activating trunk muscles. This study aims to determine whether Coordinated Locomotor Training improves lumbopelvic stability and reduces pain-related limitations in runners with mechanical low back pain compared to plyometric training. The study is a randomized controlled trial that will enroll 28 novice runners from universities in Faisalabad, Pakistan. Participants will be randomly assigned to one of two groups. One group will receive Coordinated Locomotor Training for 60 minutes per session, twice weekly, for 8 weeks. The other group will receive plyometric training for the same duration and frequency. Lumbopelvic stability will be measured using a pelvic inclinometer and a flexible ruler. Pain levels will be measured using the Numeric Pain Rating Scale. Measurements will be taken before and after the 8-week intervention period. The investigators hypothesize that Coordinated Locomotor Training will lead to greater improvements in lumbopelvic stability and greater reductions in pain compared to plyometric training.

Background: Mechanical low back pain is one of the most common musculoskeletal conditions affecting individuals globally. Lumbopelvic instability is linked to persistent pain and dysfunction in individuals with low back pain. During running, an anterior pelvic tilt is associated with an increased degree of lumbar lordosis, creating mechanical stress from repetitive loading. This stress can lead to running-related low back pain and other overuse symptoms. Novice runners are particularly vulnerable due to poor lumbopelvic control, altered biomechanics, and weak core stability.

Coordinated Locomotor Training is a neuromotor exercise approach designed to enhance synchronization of upper and lower limb movements while promoting activation of trunk and abdominal musculature. By stimulating contraction of abdominal muscles through upper and lower extremity motions in various postures, Coordinated Locomotor Training has been shown to improve postural control. However, there is limited research on the use of Coordinated Locomotor Training in novice runners, particularly for improving lumbopelvic stability and reducing pain limitations.

Study Design: This is a randomized controlled trial with double blinding (participants and outcome assessors will be blinded to group assignment). The study will be conducted at three university settings in Faisalabad, Pakistan: The University of Faisalabad, Government College University of Faisalabad, and Agriculture University of Faisalabad.

Participant Screening: Potential participants will be screened against inclusion and exclusion criteria. Inclusion criteria include age 18 to 30 years, novice runner status (less than one year of consistent running experience), history of mechanical low back pain for 6 to 12 weeks (sub-acute phase), pain intensity between 4 and 6 on the Numeric Pain Rating Scale, running frequency of 2 to 4 sessions per week with total weekly mileage less than 25 kilometers, pain aggravated by mechanical activities such as running, lifting, and prolonged standing and relieved by rest, and willingness to provide written informed consent. Exclusion criteria include participation in any structured core training or rehabilitation program within the past 3 months, history of spinal surgery or specific spinal pathology such as disc herniation or spondylolisthesis, presence of pain radiating below the knee or neurological symptoms including numbness, tingling, or weakness, current lower limb injury affecting running performance, severe pain intensity greater than 6 on the Numeric Pain Rating Scale, pregnancy or postpartum period within the last 6 months, and unwillingness to participate.

Randomization: Participants will be randomly assigned to one of two groups using a computer-generated random sequence. Allocation concealment will be maintained using sealed opaque envelopes.

Group A Intervention (Coordinated Locomotor Training): Participants will perform a 5-minute warm-up to familiarize with sprinter and skater techniques actively performed in a standing position. The main Coordinated Locomotor Training session lasts 60 minutes, given twice per week for 8 weeks (16 total sessions). Participants will perform coordinated movement training in four positions: supine, crawling, sitting, and standing. In each position, participants perform 10 repetitions per set, completing 3 sets total for approximately 30 minutes of active training. The sprinter pattern involves alternating arm and leg movements mimicking running form. The skater pattern involves lateral weight shifts with coordinated arm and leg opposition.

Group B Intervention (Plyometric Training): The warm-up consists of two sets of 30-second stimulation sessions followed by a 30-second cool-down with multidirectional hops spaced up to five seconds apart. Participants then perform six series of squat jumps with 30 seconds of activation and 30 seconds of relaxation between series. Each jump uses a 45 cm box height, with a two-second gap between each jump within each series. Total session time is 60 minutes, twice per week for 8 weeks.

Outcome Measurements: All outcome measures will be assessed at baseline (week 0) and post-intervention (week 8). The primary outcome is pain, measured using the Numeric Pain Rating Scale, an 11-point scale from 0 (no pain) to 10 (worst possible pain). The secondary outcome is lumbopelvic stability, measured using two tools. First, a handmade pelvic inclinometer measures anterior pelvic tilt by placing caliper tips on the anterior superior iliac spine and posterior superior iliac spine of the ilium, then reading the angle from the protractor scale. Second, a flexible curve ruler measures lumbar lordosis by molding a flexible piece of lead to fit the spine from T12 to S2, tracing the shape onto paper, and calculating lordosis from the curvature length and maximum width.

Data Analysis: Data will be analyzed using SPSS version 22. Descriptive statistics will be calculated for baseline characteristics. Normality of data distribution will be assessed using the Shapiro-Wilk test. For normally distributed data, between-group comparisons will be performed using independent t-tests, and within-group comparisons will be performed using paired t-tests. For non-normally distributed data, Mann-Whitney U tests will be used for between-group comparisons and Wilcoxon signed-rank tests for within-group comparisons. Statistical significance will be set at p < 0.05.

Ethical Considerations: Ethical approval has been obtained from the Institutional Review Board of The University of Faisalabad. Written informed consent will be obtained from all participants prior to enrollment. Participants will be informed of their right to withdraw from the study at any time without penalty. Confidentiality of all participant data will be maintained. The study will be conducted in accordance with the Declaration of Helsinki.

Inclusion Criteria:

• Age between 18 and 30 years
• Novice runner with less than one year of consistent running experience
• History of mechanical low back pain for 6 to 12 weeks (sub-acute phase)
• Pain intensity between 4 and 6 on the Numeric Pain Rating Scale
• Running frequency of 2 to 4 sessions per week with total weekly mileage less than 25 km
• Pain aggravated by mechanical activities (running, lifting, prolonged standing) and relieved by rest
• Willingness to participate and provide written informed consent

Exclusion Criteria:

• Participation in any structured core training or rehabilitation program within the past 3 months
• History of spinal surgery or specific spinal pathology (disc herniation, spondylolisthesis)
• Presence of pain radiating below the knee or neurological symptoms (numbness, tingling, weakness)
• Current lower limb injury affecting running performance
• Severe pain intensity greater than 6 on the Numeric Pain Rating Scale
• Pregnancy or postpartum period within the last 6 months in females