Neuromuscular adaptations in soleus and tibialis anterior muscles in persons with spinal cord injury
Year: 2025
Type: article
Study design: Observational Study
Abstract: BACKGROUND: Spinal cord injury (SCI) can lead to various neurophysiological changes, altering the neural motor control strategies. The lower limb muscles are of high importance for locomotion; however, there exists a significant knowledge gap in neurophysiological changes following SCI in these muscles. This study aims to explore the neuromuscular adaptations in the soleus and tibialis anterior muscles in persons with incomplete SCI. METHODS: Ankle joint torque, high-density electromyography (HD-EMG) and motor unit parameters of tibialis anterior and soleus were analyzed during repeated sub-maximal voluntary isometric contractions (20% and 50% of the maximal torque) and compared to those from a control cohort. RESULTS: We observed muscle-dependent alterations in motor control between the SCI and control groups. Namely, SCI group required significantly higher normalized EMG amplitudes than the control group to achieve the same contraction levels. At 50% contraction level, compared to control group, the SCI group motor units were recruited at lower thresholds in both muscles and fired at lower rates in the tibialis anterior muscle. We observed no significant differences in intramuscular motor unit coherence or muscle co-contraction between the two groups. CONCLUSIONS: The observed combination of between-group differences in motor unit behavior may indicate that even in muscles of high-functioning individuals with incomplete SCI, is a shift towards larger motor units in both tibialis anterior and soleus muscles. These results contribute to knowledge of neurophysiological modifications in major ankle muscles following a SCI and provide deeper insights into neurophysiological changes that can be used complementary to clinical SCI evaluation.
Authors: Asta Kizyte, Haocheng Zhang, Emelie Butler Forslund, Elena M. Gutierrez-Farewik, Ruoli Wang
Institutions: KTH Royal Institute of Technology, Karolinska Institutet
Language: English
Topic: Spinal Cord Injury Research
Subfield: Pathology and Forensic Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,990
OpenAlex ID: W4416224714