Relationship of kyphosis to physical fitness and bone mass on post-menopausal women.

Kyphosis is commonly associated with ageing and osteoporosis of the spine. This study was conducted to evaluate whether physical fitness and bone mass in post menopausal women, between the ages of 50-60 years, may influence the degree of kyphosis. The level of physical fitness was determined by 1) calculating maximum oxygen uptake, (VO2 max), attained by a graded exercise treadmill test, and 2) evaluating the muscle strength in performing one repetition maximum on the bench press. In vivo neutron activation analysis was used to measure the bone mineral content in the axial skeleton and proximal femurs. It is expressed as Calcium Bone Index (CaBI). The normal range was 1.00 +/- 0.12 (I.S.D.). The degree of kyphosis was measured indirectly by calculation of an index of kyphosis, (I/K), using a surveyor's flexicurve. Individuals with I/K greater than 13 showed a clinically apparent kyphosis. Fit individuals (VO2 max greater than 29 ml/kg/min) had a significantly lower I/K (p less than 0.001) than average persons. Individuals with normal bone mass (CaBI greater than 0.8) also had a significantly lower I/K (p less than 0.05) than those with bone loss. Similarly, subjects who were fit, and had normal bone mass, had a significantly lower I/K (p less than 0.001) than those who were less fit and had bone loss. There was a significant correlation between I/K and VO2 max (p less than 0.02, df 45), I/K and CaBI (p less than 0.05, df 45) and I/K and bench press (p less than 0.05, df 45).(ABSTRACT TRUNCATED AT 250 WORDS)