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Hiroki Aoki and Shinichi Demura

Purpose:

This study aimed to compare the laterality, and its gender difference, of hand grip and elbow flexion power according to load in right hand–dominant individuals.

Results:

The subjects were 15 healthy young males (age 22.1 ± 0.7 y, height 171.3 ± 3.4 cm, mass 64.5 ± 4.1 kg) and 15 healthy young females (age 22.4 ± 1.0 y, height 161.1 ± 3.0 cm, mass 55.4 ± 4.6 kg). Isotonic peak power was measured with 6 different loads ranging from 20% to 70% of maximum voluntary contraction (MVC) for grip and elbow flexion movements.

Results:

The peak power was significantly larger in males than in females in both movements (ratio, males:females was 58.1:49.4%). The dominant right hand had larger peak power in all loads for hand grip power (ratio, dominant:nondominant was 83.6:71.1%) and in loads of 20% to 50% MVC for elbow flexion power (88.7:85.7%) in both genders, confirming laterality in both movements. The peak power ratio of the dominant right hand to the nondomi-nant left hand was significantly larger in hand grip than in elbow flexion for all loads in females.

Conclusion:

Even though laterality was confirmed in both grip and elbow flexion, gender difference is more marked in hand grip.

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Shinichi Demura, Masaki Minami, Yoshinori Nagasawa, Nobuhiko Tada, Jinzaburo Matsuzawa and Susumu Sato

This cross-sectional study determined physical-fitness levels of more than 1,000 Japanese older men and women, including 338 participants who were 75 years of age and older. Each participant performed 11 tests representing 4 domains of functioning (muscular, joint, neural, and respiratory). Two-way ANOVA was used to examine gender and age differences for each variable. Performance on every test decreased with advancing age, but the declines did not occur at a uniform rate. In addition, men and women did not decline at the same rate for each variable. Although leg strength, balance ability, and reaction time did not decline until after the age of 65, they exhibited the steepest decline of all the variables after age 75. These findings suggest that significant declines in physical fitness occur with advancing age, especially those that are related to mobility and risk for falls.