Development of a finite element full spine model with active muscles for quantitatively analyzing sarcopenia effects on lumbar load

Guangming Xu; Ziyang Liang; Tengfei Tian; Qingnan Meng; Komera Musoni Bertin; Fuhao Mo

doi:10.1016/j.cmpb.2023.107709

Development of a finite element full spine model with active muscles for quantitatively analyzing sarcopenia effects on lumbar load

Comput Methods Programs Biomed. 2023 Oct:240:107709. doi: 10.1016/j.cmpb.2023.107709. Epub 2023 Jul 7.

Authors

Guangming Xu¹, Ziyang Liang², Tengfei Tian³, Qingnan Meng³, Komera Musoni Bertin³, Fuhao Mo⁴

Affiliations

¹ College of Mechanical and Vehicle Engineering, Hunan University, Changsha, Hunan 410082, China; Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, China.
² College of Mechanical and Vehicle Engineering, Hunan University, Changsha, Hunan 410082, China; Department of Orthopedics, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China.
³ College of Mechanical and Vehicle Engineering, Hunan University, Changsha, Hunan 410082, China.
⁴ College of Mechanical and Vehicle Engineering, Hunan University, Changsha, Hunan 410082, China. Electronic address: fuhaomo@hnu.edu.cn.

PMID: 37473587
DOI: 10.1016/j.cmpb.2023.107709

Abstract

Background and objective: The musculoskeletal imbalance caused by disease is one of the most critical factors leading to spinal injuries, like sarcopenia. However, the effects of musculoskeletal imbalances on the spine are difficult to quantitatively investigate. Thus, a complete finite element spinal model was established to analyze the effects of musculoskeletal imbalance, especially concerning sarcopenia.

Methods: A finite element spinal model with active muscles surrounding the vertebrae was established and validated from anatomic verification to the whole spine model in dynamic loading at multiple levels. It was then coupled with the previously developed neuromuscular model to quantitatively analyze the effects of erector spinae (ES) and multifidus (MF) sarcopenia on spinal tissues. The severity of the sarcopenia was classified into three levels by changing the physiological cross-sectional area (PCSA) of ES and MF, which were mild (60% PCSA of ES and MF), moderate (48% PCSA of ES and MF), and severe (36% PCSA of ES and MF).

Results: The stress and strain levels of most lumbar tissues in the sarcopenia models were more significant than those of the normal model during spinal extension movement. The sarcopenia caused load concentration in several specific regions. The stress level of the L4-L5 intervertebral disc and L1 vertebra significantly increased with the severity of sarcopenia and showed relatively larger values than other segments. From the normal model to a severe sarcopenia model, the stress value of the L4-L5 intervertebral disc and L1 vertebra increased by 128% and 113%, respectively. The strain level of L5-S1 also inclined significantly with the severity of sarcopenia, and the relatively larger capsule strain values occurred at lower back segments from L3 to S1.

Conclusions: In summary, the validated spinal coupling model can be used for spinal injury risk analysis caused by musculoskeletal imbalance. The results suggested that sarcopenia can primarily lead to high injury risk of the L4-L5 intervertebral disc, L1 vertebrae, and L3-S1 joint capsule regarding significant stress or strain variance.

Keywords: Finite element; Injury; Lumbar; Sarcopenia; Spine.

MeSH terms

Biomechanical Phenomena
Finite Element Analysis
Humans
Intervertebral Disc* / physiology
Lumbar Vertebrae / diagnostic imaging
Paraspinal Muscles / pathology
Sarcopenia* / pathology