Relationship Between Individual Quadriceps Muscle Quality and Fall Occurrences at a 1-Year Follow-Up

Recent studies associate computed tomography (CT) measurements of the quadriceps femoris with fall risk. However, no study has examined the relationship between falls and each individual quadriceps component. This study longitudinally investigated the association between CT values and cross-sectional areas of individual quadriceps components and the occurrence of falls 1 year later.

Single-slice CT images of the right mid-thigh were obtained at the initial visit from 246 patients (Age: 77.4 ± 6.6, Male: 80) who returned for follow-up after 1 year. The quadriceps femoris was segmented into the whole muscle, rectus femoris, vastus medialis, vastus lateralis, and vastus intermedius. For each compartment, cross-sectional area and mean CT value (average pixel value within a segmented region, representing muscle quality) were calculated. Participants were categorized into fall and non-fall groups based on new falls during the one-year follow-up. Associations between baseline measurements and subsequent falls were analyzed.

Among females in the fall group, CT values of the whole quadriceps femoris, vastus lateralis, and vastus intermedius were significantly lower (p < 0.01, p < 0.05, and p < 0.01, respectively). Binary logistic regression analysis showed that among all CT values, only that of the vastus intermedius was a predictor of falls (p < 0.01; odds ratio, 0.92; 95% confidence interval, 0.862-0.978). The cutoff value was 49.1 Hounsfield units.

Cross-sectional area was not associated with falls, whereas the CT value of the vastus intermedius was significantly associated with fall occurrence. These findings suggest that the condition of the vastus intermedius may play an important role in fall risk.