Comparison of Lower Limb COP and Muscle Activation During Single-Leg Deadlift Using Elastic and Inelastic Barbells

NCT07061314 | Completed

• 1 other identifier: BUFS-SLDL-2025
• Study Type: interventional
• Target: 27
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to investigate the effects of barbell type (elastic vs. inelastic) and lifting speed on lower limb balance and muscle activation during the Single-Leg Deadlift (SLDL) exercise. Using a randomized crossover design, healthy adults performed SLDL at three different movement speeds while center of pressure (COP) and electromyographic (EMG) responses were measured. The study seeks to determine whether elastic barbells, which create top-down perturbations, enhance neuromuscular control and postural stability more effectively than traditional inelastic barbells.

Conditions

Neuromuscular Control; Functional Training; Lower Limb Stability

Keywords

Single-Leg Deadlift; elastic barbell; inelastic barbell; sports rehabilitation; neuromuscular control

Outcome Measures

Primary Outcomes (3)

• Center of Pressure Displacement - Anterior-Posterior (AP)

  The range of anterior-posterior (AP) sway displacement (in centimeters) will be measured using a force platform (AMTI OR6). Participants perform SLDL under both barbell conditions at three different movement speeds. Lower values indicate greater postural stability.

  During single-leg deadlift task (within single session)

• Center of Pressure Displacement - Medial-Lateral (ML)

  The range of medial-lateral (ML) sway displacement (in centimeters) will be measured using a force platform (AMTI OR6). The COP variability is analyzed as an indicator of dynamic balance control.

  During single-leg deadlift task (within single session)

• Muscle Activation of Lower Limb Muscles (%MVIC)

  Surface electromyography (EMG) will be used to measure muscle activation in eight lower limb muscles during single-leg deadlifts under elastic and inelastic barbell conditions at three movement speeds (normal, fast, power). The muscles assessed include gluteus medius, rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinosus, gastrocnemius, and tibialis anterior. EMG signals will be processed using RMS and normalized to maximum voluntary isometric contraction (%MVIC). Increased %MVIC indicates higher neuromuscular demand under perturbation.

  During single-leg deadlift task (within single session)

Study Arms (1)

Single-Group Crossover

EXPERIMENTAL

Participants will perform single-leg deadlifts under two loading conditions: an elastic barbell and an inelastic barbell. Each condition will be tested at three different movement speeds (normal, fast, and power) in randomized order. Each participant completes all conditions as part of a within-subject repeated measures design

Device: Elastic Barbell; Device: Inelastic Barbell

Interventions

Elastic Barbell DEVICE

A flexible plastic barbell that creates top-down perturbations during movement. Participants perform single-leg deadlifts using this elastic bar at three different speeds: normal (2 sec), fast (1 sec), and power (as fast as possible). The bar is loaded to 30% of the participant's estimated 1RM.

Single-Group Crossover

Inelastic Barbell DEVICE

A standard rigid steel barbell with no elasticity. Participants perform single-leg deadlifts using this barbell under the same speed conditions and loading parameters as the elastic barbell.

Single-Group Crossover

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• No history of musculoskeletal disorders in the past 6 months
• At least 1 year of experience in resistance or functional training
• Able to perform single-leg deadlift exercise safely
• Provided written informed consent

You may not qualify if:

• History of lower extremity surgery or major musculoskeletal injury within the past year
• Current pain or symptoms in the hip, knee, or ankle joints
• Neurological, cardiovascular, or balance disorders
• Participation in other conflicting research studies within the last 3 months
• Inability to maintain single-leg stance for at least 5 seconds
• Presence of skin irritation or condition at electrode placement sites

Sponsors & Collaborators

• Busan University of Foreign Studies: lead

Study Sites (1)

Busan University of Foreign Studies

Busan, 46234, South Korea

Location

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Study Officials

• Ji Hwan Jeong, MSc

  Department of Sports and Health Convergence

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Crossover Assignment

Study Record Dates

• First Submitted: July 2, 2025
• First Posted: July 11, 2025
• Study Start: February 15, 2025
• Primary Completion: February 20, 2025
• Study Completion: February 28, 2025
• Last Updated: July 11, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will share
• Shared Documents: SAP
• Time Frame: The data will be available immediately after the publication of the study results and will be accessible for at least 5 years
• Access Criteria: The data will be openly available via Figshare without the need for a data access request

Locations

KR (1)