Quantitative anatomy of the growing quadratus lumborum in the human foetus

Abstract

PurposesThe purpose of the study was to quantitatively evaluate the size of the quadratus lumborum and to precisely display its growth dynamics in the human foetus.Materials and methodsUsing anatomical dissection, digital-image analysis (NIS Elements AR 3.0) and statistical analysis (Student’s t test, regression analysis), the length, width, surface area, and cross-sectional area of the quadratus lumborum were measured, and the width-to-length ratio was calculated in 58 human foetuses of both sexes (26♂, 32♀) aged 16–27 weeks.ResultsNeither sex nor right-left significant differences were found in relation with the numerical data of the growing quadratus lumborum. The length, width, and cross-sectional area of the quadratus lumborum muscle increased logarithmically, while its surface area increased proportionately to fetal age. The following growth models were computed for the quadratus lumborum: y = −70.397 + 68.501 × ln(age) ± 1.170 for length, y = −20.435 + 8.815 × ln(age) ± 0.703 for width, y = −196.035 + 14.838 × age ± 13.745 for surface area, and y = −48.958 + 20.909 × ln(age) ± 1.100 for cross-sectional area.ConclusionsThe fetal quadratus lumborum reveals neither sex nor bilateral differences. An increase in length and width of the growing quadratus lumborum follows in a commensurate fashion. The quadratus lumborum grows logarithmically with respect to its length, width, and cross-sectional area, and proportionately to age with respect to its surface area.

Morphometric properties of the tensor fascia lata muscle in human foetuses

“…In accordance with the previous study results on morphometric properties of different muscle groups [2,4,13,14,17], this study revealed a rational increase in numerical values of TFL surface area, width and lengths from 18 th to 30 th week and showed no statistically significant difference between sides and sexes.…”

“…Although literature reported a number of differences in many muscle growth dynamics between fetuses [2,4,13,14,17,25], no quantitative studies on TFL were…”

“…As the reduction of plasticity was reported as approximately 0.5-1% in the previous studies [8,14], tissue shrinkage caused by formalin fixation was disregarded. All samples were photographed from the same distance in the same position with millimetric scales (LG) and surface area was calculated using digital image analysis software (Digimizer Software).…”

Elucidating intramuscular neural distribution of the quadratus lumborum muscle to propose an optimal trigger point injection for myofascial pain syndrome

“…The muscle acts as a lumbar spine extensor, a lumbar stabilizer, and is involved in lateral tilting. The innervation occurs through the ilioinguinal nerve, the iliohypogatric nerve, and twelfth thoracic intercostal nerve [20].…”

Paediatric lumbar paravertebral sonoanatomy: More like a “Dragon fly” than a “Shamrock”

“…A study to quantitatively evaluate the QL in fetuses and its growth dynamics concluded a logarithmic increase in the length, width and cross-sectional area proportionate to age and can explain differences in paediatric musculoskeletal ultrasonography. [ 7 ] We suggest that in children a “dragonfly sign” may be more appropriate than the “Shamrock sign.”…”