Back strengthening exercises: quantitative evaluation of their efficacy for women aged 40 to 65 years

In this prospective study, the efficacy of exercise on the strength of the back extensors was evaluated. Fifty healthy women volunteers, aged 40 to 65 years (mean = 56 years), participated in a back exercise program. Subjects were screened to exclude those with diseases or treatment programs that could affect muscle strength. Seventeen subjects participated in a conventional back strengthening program, consisting mainly of antigravity upper back extension exercises in the prone position. Thirty-three control subjects continued to perform their usual athletic and daily physical activities. The control group were postmenopausal women who had volunteered to participate in a study of the effect of back strengthening exercises on bone mineral density. Subjects were blindly assigned to the control group without any selection procedures. We used this group as the control for this study because two studies were performed concurrently, and it seemed unnecessary to have two control groups. All subjects were instructed in proper posture principles. Physical activity and back extensor strength were evaluated every four to six weeks for three months. Milestones were completed by 16 subjects in the exercise group and 31 control subjects. The strength of the back extensors was significantly increased (p less than 0.001) in the exercise group. This study indicates that the back extensors can be strengthened with conventional back extension exercise.