TY - JOUR
T1 - Stress fracture in military recruits
T2 - Gender differences in muscle and bone susceptibility factors
AU - Beck, T. J.
AU - Ruff, C. B.
AU - Shaffer, R. A.
AU - Betsinger, K.
AU - Trone, D. W.
AU - Brodine, S. K.
N1 - Funding Information:
The authors thank the staff at the U.S. Marine Corps Recruit Depot, Parris Island, SC, for their support and cooperation, in particular, the successive commanding officers of the Fourth Recruit Training Battalion, Lt. Col. G. Jane Harmon and Lt. Col. Angela Salinas, USMC. In addition, we are grateful for the assistance of Chief Medical Officer CAPT Kenneth Long, MC, and the staff of the U.S. Naval Hospital Beaufort Branch Medical Clinic. The organizational skills of Mary Durm during the initiation of the study were instrumental in its success. We are grateful to David J. Sartoris, M.D., for the use of the DXA scanner. This work was supported in part by U.S. Navy Contract #92-0306-27V and by U.S. Army Contract #DEAMD17-95-2-5027, under the Defense Women’s Health Research Program (DWHRP), project title: “Use of noninvasive bone structural measurements to evaluate stress fracture susceptibility among female recruits in U.S. Marine Corps basic training.” The views expressed in this article are those of the authors and do not reflect official policy or position of the Department of the Navy, Department of Defense, or the U.S. Government.
PY - 2000/9
Y1 - 2000/9
N2 - A total of 693 female U.S. Marine Corps recruits were studied with anthropometry and dual-energy X-ray absorptiometry (DXA) scans of the midthigh and distal third of the lower leg prior to a 12 week physical training program. In this group, 37 incident stress fracture cases were radiologically confirmed. Female data were compared with male data from an earlier study of 626 Marine recruits extended with additional cases for a total of 38 stress fracture cases. Using DXA data, bone structural geometry and cortical dimensions were derived at scan locations and muscle cross- sectional area was computed at the midthigh. Measurements were compared within gender between pooled fracture cases and controls after excluding subjects diagnosed with shin splints. In both genders, fracture cases were less physically fit, and had smaller thigh muscles compared with controls. After correction for height and weight, section moduli (Z) and bone strength indices (Z/bone length) of the femur and tibia were significantly smaller in fracture cases of both genders, but patterns differed. Female cases had thinner cortices and lower areal bone mineral density (BMD), whereas male cases had externally narrower bones but similar cortical thicknesses and areal BMDs compared with controls. In both genders, differences in fitness, muscle, and bone parameters suggest poor skeletal adaptation in fracture cases due to inadequate physical conditioning prior to training. To determine whether bone and muscle strength parameters differed between genders, all data were pooled and adjusted for height and weight. In both the tibia and femur, men had significantly larger section moduli and bone strength indices than women, although women had higher tibia but lower femur areal BMDs. Female bones, on average, were narrower and had thinner cortices (not significant in the femur, p = 0.07). Unlike the bone geometry differences, thigh muscle cross-sectional areas were virtually identical to those of the men, suggesting that the muscles of the women were not relatively weaker. (C) 2000 by Elsevier Science Inc.
AB - A total of 693 female U.S. Marine Corps recruits were studied with anthropometry and dual-energy X-ray absorptiometry (DXA) scans of the midthigh and distal third of the lower leg prior to a 12 week physical training program. In this group, 37 incident stress fracture cases were radiologically confirmed. Female data were compared with male data from an earlier study of 626 Marine recruits extended with additional cases for a total of 38 stress fracture cases. Using DXA data, bone structural geometry and cortical dimensions were derived at scan locations and muscle cross- sectional area was computed at the midthigh. Measurements were compared within gender between pooled fracture cases and controls after excluding subjects diagnosed with shin splints. In both genders, fracture cases were less physically fit, and had smaller thigh muscles compared with controls. After correction for height and weight, section moduli (Z) and bone strength indices (Z/bone length) of the femur and tibia were significantly smaller in fracture cases of both genders, but patterns differed. Female cases had thinner cortices and lower areal bone mineral density (BMD), whereas male cases had externally narrower bones but similar cortical thicknesses and areal BMDs compared with controls. In both genders, differences in fitness, muscle, and bone parameters suggest poor skeletal adaptation in fracture cases due to inadequate physical conditioning prior to training. To determine whether bone and muscle strength parameters differed between genders, all data were pooled and adjusted for height and weight. In both the tibia and femur, men had significantly larger section moduli and bone strength indices than women, although women had higher tibia but lower femur areal BMDs. Female bones, on average, were narrower and had thinner cortices (not significant in the femur, p = 0.07). Unlike the bone geometry differences, thigh muscle cross-sectional areas were virtually identical to those of the men, suggesting that the muscles of the women were not relatively weaker. (C) 2000 by Elsevier Science Inc.
KW - Bone geometry
KW - Bone mass
KW - Bone strength
KW - Dual-energy X-ray absorptiometry (DXA)
KW - Gender differences in bone strength
KW - Muscle size
KW - Muscle strength
KW - Stress fracture susceptibility
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U2 - 10.1016/S8756-3282(00)00342-2
DO - 10.1016/S8756-3282(00)00342-2
M3 - Article
C2 - 10962357
AN - SCOPUS:0033835154
SN - 8756-3282
VL - 27
SP - 437
EP - 444
JO - Bone
JF - Bone
IS - 3
ER -