Tomographical description of tennis-loaded radius: reciprocal relation between bone size and volumetric BMD.
Effects of long-term tennis loading on volumetric bone mineral density (vBMD) and geometric properties of playing-arm radius were examined. Paired forearms of 16 tennis players (10 women) and 12 healthy controls (7 women), aged 18-24 yr, were scanned at mid and distal site by using peripheral quantitative computerized tomography. Tomographic data at midradius showed that tennis playing led to a slight decrease in cortical vBMD (-0.8% vs. nonplaying arm, P < 0. 05) and increase both in periosteal and endocoritcal bone area (+15. 2% for periosteal bone, P < 0.001; and +18.8% for endocortical bone, P < 0.001). These data suggest that, together with an increase in cortical thickness (+6.4%, P < 0.01), cortical drift toward periosteal direction resulted in improvement of mechanical characteristics of the playing-arm midradius. Enlargement of periosteal bone area was also observed at distal radius (+6.8%, P < 0.01), and the relative side-to-side difference in periosteal bone area was inversely related to that in trabecular vBMD (r = -0.53, P < 0.05). We conclude that an improvement of mechanical properties of young adult bone in response to long-term exercise is related to geometric adaptation but less to changes in vBMD.
Ashizawa
N
N
Growth Factor Division, National Cancer Center Reseach Institute, Tsukiji, Chuo-ku, Tokyo 104, Japan.
Nonaka
K
K
Michikami
S
S
Mizuki
T
T
Amagai
H
H
Tokuyama
K
K
Suzuki
M
M
D000328:Adult; D015519:Bone Density; D005260:Female; D006801:Humans; D008297:Male; D011884:Radius / Q000000981:diagnostic imaging* / Q000502:physiology*; D012016:Reference Values; D012727:Sex Characteristics; D013715:Tennis; D014057:Tomography, X-Ray Computed