Development of predictive equations for estimating regional cross-sectional areas of the quadriceps femoris in untrained young women using anthropometric measurements
Igor Henrique de Aguiar Leite, Igor José Soares Rodrigues, Giovanna Pernetti, Kailany da Costa Pires, Frank Douglas Tourino, Rodrigo César Ribeiro Diniz et al. · Muscles Ligaments and Tendons Journal · 2026
Background: The assessment of muscle cross-sectional area (CSA) is widely used in both clinical and performance contexts, as it reflects morphological changes associated with strength training-induced hypertrophy and muscle atrophy in conditions such as sarcopenia. Although imaging techniques such as computed tomography, magnetic resonance imaging, and ultrasonography provide accurate analyses of CSA, their high cost and the need for specialized professionals limit their routine application. In this context, low-cost indirect
Methods: , such as anthropometric measurements, emerge as viable alternatives.
Aim: This study aimed to develop predictive equations to estimate the CSA of the quadriceps femoris (QF) muscle and its respective portions, rectus femoris (RF), vastus lateralis (VL), vastus intermedius (VI), and vastus medialis (VM), using thigh circumference and skinfold measurements taken at 50% and 70% of femur length, with ultrasonography as the reference
Method: .
Materials and methods: Thirty-six untrained young women participated (body mass: 56.08 ± 17.79 kg; height: 1.60 ± 0.05 m; age: 21.00 ± 2.16 years). Circumference and skinfold thickness measurements were taken at both 50% and 70% of femur length (FL) for each muscle. Muscle CSA was assessed using panoramic-view ultrasonography.
Results: Ten multiple linear regression equations were developed, six of which showed relative errors ranging from 7.2% to 19.9%, which are comparable to or lower than values reported in existing models, given the equations 50% of CF for VL r 2 = 0.351; SEEr = 12.4%, VI r 2 = 0.5046; SEEr = 13.5%, VM r 2 = 0.190; SEEr = 12.9% and QF r 2 = 0.356; SEEr = 12.4% and at 70% of CF for VI r 2 = 0.200; SEEr = 17.8% and QF r 2 = 0.356; SEEr = 12.4%.
Conclusions: The
results presented indicate that, although some equations have moderate coefficients of determination, the error levels found demonstrate potential for application, as they approach the precision of already established equations.