This report deals with the analysis of data from a 3-year clinical trial on the effect of walking on postmenopausal bone loss. Two hundred fifty-five women, with an average age of 57 at entry, were randomized into two groups, a walking and a control group. Bone measures in the shaft of the radius were carried out with a CT scanner in search of generalized skeletal effects rather than effects localized to the bones of the leg. Although bone density losses were comparable in the two randomized groups, changes in the cross-sectional area of the radius were significantly greater in the walkers with high grip strength (greater than 25 Kg) than in the controls with comparable high grip strength which corresponded to the upper half range of the grip-strength distribution. It is concluded that the moderate activity of walking exerted systemically positive effects on the radius which, within the protocol of the study, could be substantiated only when synergized with inherent muscle strength.