. 2008 Dec 15;10(6):R143. doi: 10.1186/ar2573

Table 1.

Characteristics of the study population (n = 297)

	Mean (SD)^a
Age at magnetic resonance imaging, years	59.1 (6.3)
Females, number (percentage)	186 (63)
Body mass index, kg/m²	25.2 (3.8)
Participation in vigorous physical activity, number of subjects (percentage)^b	107 (36)
Distal vastus medialis cross-sectional area, mm²	1,171 (306)
Distal vastus lateralis cross-sectional area, mm²	333 (127)
Patella cartilage volume, mm³	2,656 (886)
Patella bone volume, mm³	20,276 (4,667)

^aValues are reported as mean (standard deviation, SD) unless otherwise stated. ^bParticipation in vigorous physical activity at least once or twice a week or at least three times per week (over the last 6 months) for a period of 20 minutes that leads to sweating or dyspnoea.