QUANTITATIVE ULTRASONOGRAPHY OF MUSCLE - DETECTION OF ADAPTATIONS TO TRAINING IN ELDERLY WOMEN

Objective: To develop quantitative ultrasonography in studying the ada ptation of quadriceps muscle mass and composition to short-term physic al training and rehabilitation in elderly women. Design: Randomized co ntrol trial. Setting: Measurements in a research laboratory and traini ng in a fitness center and sports hall. Participants: Forty-two women, aged 76 to 78 years, with no indications against intensive physical e xercise, randomly assigned to strength (n = 16), endurance (n = 15), a nd control (12 = 11) groups. Twelve subjects from the strength, 12 fro m the endurance, and 11 from the control group completed the study. In tervention: Supervised physical training 3 times a week for 18 weeks. Strength training: 3 to 4 sets of 8 to 10 repetitions with a load of 6 0% to 75% of the subjects' 1-repetition maximum. Endurance training: t rack walking and step aerobics at an intensity of 50% to 80% of maximu m heart-rate reserve. Main Outcome Measures: Ultrasonographic measurem ents of the quadriceps cross-sectional area (CSA), thickness, and weig hted mean grey shades of vastus lateralis (MGS(VL)) and femur (MGS(F)) . Results: No significant interaction of group by time was observed in any of the outcome measures. The changes observed in CSA in the stren gth group correlated with those measured by computed tomography report ed earlier. MGS(VL) decreased and MGS(F) increased in the strength gro up, suggesting a decreased proportion of fat in the muscle. Conclusion s: Quantitative ultrasonography is a potentially useful tool for study ing skeletal muscle in elderly women. The precision and accuracy of th e method, however, should be improved to reveal the adaptation of agin g muscles to short-term physical training and rehabilitation programs. (C) 1996 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation