Efficacy of Core Stability Training on Endurance, Kinetic Chain Function, and Dynamic Balance in Soccer Players

Efficacy of Core Stability Training on Endurance, Kinetic Chain Function, and Dynamic Balance in Healthy Adult Soccer Players: A Randomized Controlled Trial

Background: The core has two functions, both critical to soccer performance. The first is to provide proximal stability, allowing efficient mobility at the distal parts. This function requires a submaximal contraction of core muscles for as long as the movement takes. It was reported that core endurance is the construct most closely representing this function. The second function is generating and transferring forces from one extremity to another. This function operates via the kinetic chain theory, which implies that various body parts are connected through myofascial kinetic chains, and that a defect in one part of the chain can lead to faulty mechanics and balance, potentially causing injuries in other parts of that chain.

Aim: To investigate the efficacy of core stability training on core endurance, lower limb kinetic chain function, and lower limb dynamic balance in professional, healthy young adult soccer players.

Methods: This is a randomized, controlled trial with a parallel, two-arm, pre- and post-design. After screening for eligibility and obtaining participants' consents, at least 28 male and female soccer players will be randomly assigned to intervention and control groups and tested before and after eight weeks of core training intervention. The outcome measures include the Sport-specific Endurance Plank test, the Closed Kinetic Chain Lower Extremity Stability test, and the modified Star Excursion Balance test.

Data Analysis: The Shapiro-Wilk test, Q-Q plots, and Box plots will be used to evaluate the normality of the data. Lavan's test will check the homogeneity of variances. Based on the normality results, parametric or non-parametric tests will be implemented to compare within and between groups. A P-value of <0.05 will be used to reflect the significance of the results. An intention-to-treat (ITT) analysis will be employed to address potential missing data.

Keywords: core stability, endurance, kinetic chain, athletes, soccer.

Study Overview

• Status: Not yet recruiting
• Conditions: The Study Investigates the Efficacy of Core Stability Training on Core Endurance and Kinetic Chain Function and Dynamic Balance in Healthy Adult Soccer Players
• Intervention / Treatment: Other: Core stability exercises; Other: Regular soccer training

• Study Type: Interventional
• Enrollment (Estimated): 28
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy, young adult soccer players of both genders between 18 and 35 years.
• Normal Body mass index (BMI) according to the World Health Organization (WHO) guidelines (18.5-24.9).
• Normal waist circumference (<88 cm for women and < 102 cm for men).

Exclusion Criteria:

• As reported by participants, they will be excluded if they have a history of:

  • Chronic diseases (e.g., cardiovascular diseases, diabetes mellitus, hypertension).
  • Peripheral vascular diseases (e.g., deep venous thrombosis).
  • Systemic diseases (e.g., rheumatoid arthritis, lupus erythematosus)
  • Limbs or trunk trauma, injuries, fractures, or surgeries that required medical attention in the past six months.
  • Concussion.
  • Neurological deficits or symptoms (e.g., numbness, referred to pain to the lower limbs, burning sensation).
  • The use of any medications that might affect the testing procedure and training.
  • Physical pain (e.g., back pain, limb pain).
  • Red flags (e.g., sudden loss of weight, night sweats, or fever).
  • Pregnancy and post-partum (1 year)

• Upon inspection and palpation by the primary researcher, participants will be excluded if they have:

  • Biomechanical abnormalities or deformities in the upper or lower limbs.
  • Swelling/ edema
  • Leg length discrepancy.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: core training group; This group will receive core stability training + their regular soccer training	Other: Core stability exercises; exercises for the trunk, pelvic, and hip muscles; Other: Regular soccer training; the routine exercises performed regularly by soccer players
Active Comparator: control group; this group will continue their usual soccer training	Other: Regular soccer training; the routine exercises performed regularly by soccer players

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sport-specific Endurance Plank test	Participants will start with a standard prone plank position on a bench supported on their elbows and feet. They must keep their head, torso, pelvis, and heels in a straight line and their elbows aligned vertically with their shoulders. While maintaining this position for 60 seconds (s), they will perform several tasks consecutively: (1) raise their right arm for 15 s, then lower it and raise their left arm for 15 seconds, then lower it down; (2) lift the right leg (in a straight position) for 15 s, then lower it and lift the left leg for 15 seconds and lower it down; (3) raise the right arm and left leg (diagonally) for 15 s and lower them down; (4) raise the left arm and right leg (diagonally) for 15 s and lower them down; (5) keep the prone plank position for 30s. Then, participants will repeat the same steps (1-5) until the prone plank position cannot be maintained.	60 seconds
Closed Kinetic Chain Lower Extremity Stability Test	First, participants will be asked to lie on the floor mat in a prone plank position; their feet will be apart at shoulder width. While maintaining the prone plank position with their body kept in a straight line, participants will be asked to start crossing their legs alternately as fast as possible for 15 seconds. The Assessor will start the stopwatch, pre-setted for 15 seconds when the participants start moving. The assessor will simultaneously and manually count the number of successful crosses each participant can make during those 15 seconds. A successful cross is defined as participants touching, with their moving foot, the floor at the lateral side of their stationary foot and then fully returning to the starting position.	15 seconds

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Modified Star Balance Excursion Test	The floor will be taped with three crossing lines. Participants will be asked to stay barefoot and to stand upright with one foot (foot of the testing limb) positioned in the middle of the grid. The most distal part of the big toe of the stance leg should be placed just at the crossroad between the three lines. The position of the stationary foot should remain constant throughout the whole testing procedure. Moreover, participants' hands shall remain on their hips throughout the test to focus on the lower limb performance. Participants will then be asked to reach as far as possible with the other limb in each of the three directions. They should touch (without weight bearing) the line where they can maximally reach by the most distal part of the big toe and return to the starting position without losing their balance. Using a tape measure, the assessor will measure and record the distance (in centimeters) reached.	10 minutes

Collaborators and Investigators

• Sponsor: Imam Abdulrahman Bin Faisal University

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2026
• Primary Completion (Estimated): April 1, 2026
• Study Completion (Estimated): April 30, 2026

Study Registration Dates

• First Submitted: December 24, 2025
• First Submitted That Met QC Criteria: December 24, 2025
• First Posted (Actual): January 8, 2026

Study Record Updates

• Last Update Posted (Actual): January 8, 2026
• Last Update Submitted That Met QC Criteria: December 24, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Keywords: core stability, endurance, kinetic chain, athletes, soccer.
• Other Study ID Numbers: IRB-PGS-2025-03-0529

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: To ensure the confidentiality of our participants' information.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No