Influence of knee alignment on quadriceps cross-sectional area

• Published in: Journal of biomechanics Vol. 42; no. 14; pp. 2313 - 2317
• Main Authors: Sogabe, Akitoshi, Mukai, Naoki, Miyakawa, Shunpei, Mesaki, Noboru, Maeda, Kazuaki, Yamamoto, Tadashi, Gallagher, Philip M, Schrager, Matt, Fry, Andrew C
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 16.10.2009; Elsevier Limited
• Subjects: Adult; Anatomy, Cross-Sectional; Genu valgum; Genu varum; Humans; Knee; Knee Joint - abnormalities; Knee Joint - pathology; Male; Models, Anatomic; MRI; Muscle, Skeletal - pathology; Muscular system; Pain; Physical Medicine and Rehabilitation; Studies; VM/VL ratio; VM/VL ratio; Genu varum; Genu valgum; MRI
• ISSN: 0021-9290; 1873-2380
• DOI: 10.1016/j.jbiomech.2009.06.022

Abstract Previous studies of methods for stimulating the individual muscles composing the quadriceps femoris have not considered the structural features of a subject's knee joint. In this study, we compared the ratios of the individual muscles composing the quadriceps between subjects with different knee alignments using magnetic resonance (MR) imaging. A total of 18 healthy males were examined: 6 normal knees (age, 23.0±0.6 yr; femorotibial angle (FTA), 176.8±0.4°), 6 genu varum (age, 21.8±2.9 yr; FTA, 181.7±2.6°) and 6 genu valgum (age, 21.0±1.6 yr; FTA, 172.3±1.5°). The cross-sectional areas (CSAs) of quadriceps muscles were obtained by MR imaging of the entire left thigh. The CSAs of the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM) and vastus intermedius (VI) muscles were obtained by MR imaging of the entire left thigh in a supine position. The VM/VL ratio was also obtained by dividing the CSA of the VM by that of the VL and compared among the three groups of subjects with different knee alignments. The genu varum group showed a significantly higher %CSA of VM in the CSA of the quadriceps (VM/Quad) (49.0±2.6%) than values for the other two groups. The genu valgum group showed significantly higher values of RF/Quad (15.2±2.1%) and VL/Quad (40.6±4.0%) than the other groups. The VM/VL ratio was significantly higher in the genu varum than in values for the other two groups. This difference in CSA, in respect to knee alignment, may be considered when devising muscle training programs.