Leg Muscle Mass and Foot Symptoms, Structure, and Function: The Johnston County Osteoarthritis Project.
BACKGROUND
Loss of muscle mass occurs with aging and in lower limbs it may be accelerated by foot problems. In this cross-sectional analysis, we evaluated the relationship of leg muscle mass to foot symptoms (presence or absence of pain, aching, or stiffness), structure while standing (high arch or low arch), and function while walking (pronated or supinated) in a community-based study of Caucasian and African American men and women who were 50-95 years old.


METHODS
In the Johnston County Osteoarthritis Project, leg muscle mass was measured with whole body dual-energy x-ray absorptiometry, and plantar foot pressure data, using predetermined values, were used to classify foot structure and function. Sex-specific crude and adjusted (age, body mass index, and race) linear regression models examined associations of leg muscle mass index (Leg muscle mass [kg]/Height [m](2)) with foot symptoms, structure, and function.


RESULTS
Complete data were available for 1,037 participants (mean age 68 years, mean body mass index 31 kg/m(2), 68% women, 29% African American). In women, pronated foot function was associated with lower leg muscle mass in crude (p = .02), but not adjusted (p = .22), models. A low arch was associated with a higher leg muscle mass in adjusted models for both men and women (p < .01).


CONCLUSIONS
Leg muscle mass was associated with foot structure in our biracial sample, whereas relations between leg muscle mass and foot function were attenuated by age, body mass index, and race. Future longitudinal analyses are needed to explain the temporal relationship between these conditions and how they relate to other aspects of impairment and physical function.
['Golightly|Yvonne M|YM|', 'Dufour|Alyssa B|AB|', 'Hannan|Marian T|MT|', 'Hillstrom|Howard J|HJ|', 'Katz|Patricia P|PP|', 'Jordan|Joanne M|JM|']
D015502:Absorptiometry, Photon D000368:Aged D000375:Aging D015992:Body Mass Index D003430:Cross-Sectional Studies D005260:Female D005500:Follow-Up Studies D005528:Foot D005684:Gait D006801:Humans D015994:Incidence D007866:Leg D008297:Male D018482:Muscle, Skeletal D009657:North Carolina D010003:Osteoarthritis D011312:Pressure D011446:Prospective Studies D016138:Walking
Muscle Foot Pain Cohort study Gait