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

Busan University of Foreign Studies

Status: Completed

Conditions: Lower Limb Stability; Functional Training; Neuromuscular Control

Treatments: Device: Elastic Barbell; Device: Inelastic Barbell

Study type: Interventional

Funder types: Other

Identifiers

NCT07061314

BUFS-SLDL-2025

Details and patient eligibility

About

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.

Full description

This randomized clinical trial examines how barbell type and movement speed affect lower limb stability and muscle activation during Single-Leg Deadlift (SLDL) exercises. The intervention compares elastic barbells-designed to generate upper-limb-initiated dynamic perturbations-to conventional inelastic barbells. Twenty-seven healthy adults with prior resistance training experience participated in the study. All participants performed SLDL using both barbell types across three speeds: normal (2 seconds), fast (1 second), and power (as fast as possible).

Center of Pressure (COP) data were recorded using a force platform to assess anterior-posterior (AP) and medial-lateral (ML) sway. Surface electromyography (EMG) was collected from eight lower limb muscles to evaluate neuromuscular responses. Data were analyzed using two-way repeated measures ANOVA.

The findings revealed that elastic barbells significantly reduced COP displacement and increased activation in the gluteus medius, biceps femoris, semitendinosus, and gastrocnemius muscles-particularly at high movement speeds. These results suggest that elastic barbells may improve dynamic stability and neuromuscular coordination, offering potential applications in sports rehabilitation and unilateral training programs.

Enrollment: 27 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• 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

Exclusion criteria

• 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

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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27 participants in 1 patient group

Single-Group Crossover

Experimental group

Description:

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

Treatment:

Device: Inelastic Barbell

Device: Elastic Barbell