Knee extensor strength, activation, and size in very elderly people following strength training

✍ Scribed by Stephen D.R. Harridge; Ann Kryger; Anders Stensgaard

• Book ID: 102652979
• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 593 KB
• Volume: 22
• Category: Article
• ISSN: 0148-639X
• DOI: 10.1002/(sici)1097-4598(199907)22:7<831::aid-mus4>3.0.co;2-3

✦ Synopsis

Muscle strength, activation, and size were studied in 11 very elderly subjects (8 women and 3 men; age range, 85-97 years) who completed 12 weeks of strength training of the knee extensor muscles. Training increased the maximum amount of weight that could be lifted once (134%; P < 0.05) and maximum voluntary isometric strength, measured as both force recorded at the ankle with the knee flexed 90°(17%, ns) and as torque with the knee flexed 60°(37%; P < 0.05). Anatomical lean quadriceps crosssectional area (LCSA) measured at midthigh using magnetic resonance imaging increased from 27.5 ± 9.6 cm 2 to 30.2 ± 10.0 cm 2 (9.8%; P < 0.05) after training. Both before and after training, isometric strength was closely related to LCSA, but training resulted in no significant change in muscle force per unit area of quadriceps muscle. Using the twitch interpolation technique, muscle activation during a maximal voluntary isometric contraction was shown to be incomplete in all subjects before training (ranging from 69% to 93%) and was not significantly increased after training. An increase in skeletal muscle mass may have important functional and metabolic benefits for very elderly people.