MRI metrics can help explain the loss of functional strength in aging

Motivation: There is a need to investigate the relationship between age-related muscle atrophy and functional strength. Goal(s): To explore the relationship between volumes of individual knee extensor muscles relative to total volume of the quadriceps as measured by MRI and sit to stand performance. Approach: Participants performed a sit to stand test while being recorded by a markerless motion capture system and underwent an MRI exam that included a Dixon scan, which was used to calculate muscle volumes in the quadriceps. Results: There were correlations between age and vastus intermedius and vastus lateralis volume. Rectus femoris volume was correlated with sit to stand performance. Impact: We utilized a novel experimental design using smartphone-based markerless motion capture and MRI metrics to study the relationship between functional strength and age-related muscle atrophy. This work could inform design of physical therapy programs for the elderly.