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Updated: Jul 19, 2026
Biomechanical Changes Related to Low Back Pain: An Innovative Tool for Movement Pattern Assessment and Treatment Evaluation in Rehabilitation
Published on: December 13, 2024
Lumbosacral orthoses reduce trunk muscle activity in a postural control task
Jacek Cholewicki1, N Peter Reeves, Vanessa Q Everding
1Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, P.O. Box 208071, New Haven CT 06520 8071, USA. jacek.cholewicki@yale.edu
A lumbosacral orthosis (LSO) reduces trunk muscle activity, particularly in the thoracic and lumbar erector spinae, without compromising spine stability during challenging balance tasks. This finding supports potential benefits for individuals with low back pain.
Area of Science:
- Biomechanics
- Orthopedics
- Human Movement Science
Background:
- Biomechanical modeling suggested lumbosacral orthoses (LSO) reduce trunk muscle activity by 1-14% without sacrificing spine stability.
- Previous research predicted specific muscle groups would show the greatest EMG reduction with LSO use.
Purpose of the Study:
- To experimentally validate theoretical predictions regarding LSO effects on trunk muscle activity during an unstable sitting task.
- To assess the impact of an LSO on balance performance and electromyography (EMG) in healthy adults.
Main Methods:
- Healthy participants (n=23) performed a 20-second unstable sitting balance task on a force plate.
- Electromyography (EMG) of abdominal and erector spinae muscles was recorded with and without an LSO.
- Balance performance was quantified by center of pressure (CoP) velocity.
Main Results:
- No significant difference in balance performance (CoP velocity) was observed between LSO and no-LSO conditions (p=0.13).
- EMG activity was significantly reduced in the thoracic erector spinae (TES) and lumbar erector spinae (LES) when wearing the LSO (p=0.02 and p=0.01, respectively).
- Abdominal muscle activity (rectus abdominis, external oblique) showed no significant change with LSO use.
Conclusions:
- Experimental results align with biomechanical modeling, confirming reduced erector spinae muscle activity with LSO use during a postural task.
- The observed reduction in muscle co-contraction suggests potential therapeutic benefits for low back pain patients experiencing elevated muscular activity.
- LSO application may offer a non-invasive strategy to modulate muscle recruitment patterns and alleviate pain.
