Year: 2019
Type: article
Abstract: The effects of long-duration spaceflight on crewmember neck musculature have not been adequately studied. The purpose of this study was to evaluate the changes in the neck musculature on pre-flight and post-flight magnetic resonance imaging (MRI) examinations of six crewmembers on 4- to 6-month missions equipped with the advanced resistive exercise device (aRED). The MRI images were resliced to remove variations in spinal curvature, the cross-sectional area (CSA), and muscle fat infiltration (MFI) of neck musculature at the C1-C2, C4-C5, C7-T1, and T1-T2 intervertebral disc levels were measured bilaterally. Percent changes in the neck muscle CSA and fatty infiltration following spaceflight were calculated, and mixed models were used to assess significance of these changes. Crewmembers on missions equipped with the aRED experienced an average 25.1% increase in CSA for the trapezius muscle at C6-C7, an average 11.5% increase in CSA for the semispinalis capitis muscle at C4-C5, an average 9.0% increase in CSA for the sternocleidomastoid muscle at C4-C5, and an average 23.1% increase in CSA for the rhomboid minor at T1-T2. There were no significant changes in the CSA of the levator scapulae, splenius capitis, rectus capitis posterior major, scalenus anterior, scalenus posterior, scalenus medius, longissimus capitis, or obliquus capitis inferior muscles at the locations measured. None of the muscles analyzed experienced statistically significant changes in fatty infiltration with spaceflight. Our study indicates that long-duration spaceflight conditions are associated with preservation of CSA in most neck muscles and significant increases in the CSAs of the trapezius, semispinalis capitis, sternocleidomastoid, and rhomboid minor muscles. This may indicate that cervical muscles are not subjected to the same degradative effects microgravity imparts on the majority of muscles.
Source: Frontiers in Physiology
Authors: Kyle P. McNamara, Katelyn A. Greene, Janet A. Tooze, Jade Dang, Karim Khattab, Leon Lenchik, Ashley A. Weaver
Language: English
Subfield: Physiology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,950
Awards: REU Site: Imaging and Mechanics-based Projects on Accidental Cases of Trauma (IMPACT), QUANTITATIVE CT AND MRI-BASED MODELING ASSESSMENT OF DYNAMIC VERTEBRAL STRENGTH AND INJURY RISK FOLLOWING LONG-DURATION SPACEFLIGHTPROLONGED PERIODS OF NEAR WEIGHTLESSNESS CAN CAUSE DAMAGE TO ASTRONAUTS MUSCULOSKELETAL SYSTEM. THIS DAMAGE CAN INCREASE THE RISK OF SKELETAL TISSUE FAILURE (E.G. FRACTURES TEARS) WHEN EXPERIENCING FORCEFUL DYNAMIC LOADS. FRACTURES OF THE SPINE DURING DYNAMIC CONDITIONS SUCH AS LAUNCH OR LANDING COULD CAUSE A MISSION TO FAIL. THIS STUDY WILL MEASURE THIS DEGRADATION OF ASTRONAUTS VERTEBRAE AND SPINAL MUSCLES DURING MISSIONS ABOARD THE INTERNATIONAL SPACE STATION (ISS). WE WILL THEN DETERMINE THE EXTENT OF VERTEBRAL WEAKENING OF CREWMEMBERS DURING LONG-DURATION MISSIONS.CHANGES IN PRE- AND POST-FLIGHT VERTEBRAL GEOMETRY VOLUME CORTEX THICKNESS AND BONE MINERAL DENSITY WILL BE MEASURED FROM EXISTING LUMBAR QUANTITATIVE COMPUTED TOMOGRAPHY (QCT) SCANS AS WELL AS FROM PLANNED QCT SCANS OF THE CERVICAL THORACIC AND LUMBAR SPINE FROM SIX ISS CREWMEMBERS. LIKEWISE THE PRE- AND POST-FLIGHT SPINAL MUSCLE VOLUMES WILL BE ANALYZED USING BOTH EXISTING MAGNETIC RESONANCE IMAGING (MRI) SCANS AND PLANNED MRI SCANS FROM SIX ISS CREWMEMBERS. THE QCT AND MRI SCANS WILL BE ANALYZED TODETERMINE STRUCTURAL AND MATERIAL CHANGES IN THE CERVICAL THORACIC AND LUMBAR VERTEBRAE AND THE SPINAL MUSCLES THAT INDICATE DAMAGE WHICH COULD WEAKEN THESE TISSUES.OUR UNIQUE ENGINEERING APPROACH WILL MEASURE THE LOSS OF VERTEBRAL STRENGTH DURING SPACEFLIGHT CONDITIONS AND PREDICT THE RISK OF FAILURE DURING TRAUMATIC DYNAMIC LOADING CONDITIONS SUCH AS LAUNCH OR LANDING. VERTEBRAL STRENGTH AND RISK FOR VERTEBRAL FRACTURE AND INJURY WILL BE QUANTIFIED IN 900 DYNAMIC SIMULATIONS USING A FULL HUMAN BODY MODEL THAT IS CONSTRUCTED USING STRUCTURAL AND MATERIALDATA GATHERED FROM THE PRE- AND POST-FLIGHT MEDICAL IMAGES FOR EACH ASTRONAUT.THIS STUDY HAS SIGNIFICANCE IN QUANTIFYING AND ADDRESSING RISKS OF LONG-DURATION SPACEFLIGHT INCLUDING VERTEBRAL INJURY FROM DYNAMIC LOADS VERTEBRAL FRACTURE EARLY ONSET VERTEBRAL OSTEOPOROSIS DUE TO SPACEFLIGHT AND IMPAIRED PERFORMANCE DUE TO REDUCED SPINAL MUSCLE MASS STRENGTH AND ENDURANCE.
OpenAlex ID: W2968091133