Conclusions : Age-related differences support the impact of stroke-related sarcopenia as a contributor to hemiparetic muscle dysfunction .
Abstract Background : Despite extensive study of the impact of stroke on muscle and functional performance , questions remain regarding the extent to which changes are due to the neurological injury vs. age-related loss of morphology and force production .
Objectives : To synthesize available evidence describing post-stroke changes in lower extremity muscle size and strength compared to healthy adults .
Muscle quality. I. Age-associated differences between arm and leg muscle groups.
To determine the differences between arm and leg muscle quality ( MQ ) across the adult life span in men and women , concentric ( Con ) and eccentric ( Ecc ) peak torque ( PT ) were measured in 703 subjects ( 364 men and 339 women , age range 19 - 93 yr ) and appendicular skeletal muscle mass ( MM ) was determined in the arm and leg in a subgroup of 502 of these subjects ( 224 men and 278 women ) . Regression analysis showed that MQ , defined as PT per unit of MM , was significantly higher in the arm ( approximately 30 % ) than in the leg across age in both genders ( P < 0.01 ) . Arm and leg MQ declined at a similar rate with age in men , whereas leg MQ declined approximately 20 % more than arm MQ with increasing age in women ( P < /= 0.01 and P < 0.05 for Con and Ecc PT , respectively ) . Moreover , the age-associated decrease in arm MQ was steeper in men than in women whether Con or Ecc PT was used ( both P < 0.05 ) . Arm MQ as determined by Con PT showed a linear age-related decline in men and women ( 28 and 20 % , respectively , P < 0.001 ) , whereas arm MQ as determined by Ecc PT showed a linear age-related decline in men ( 25 % , P < 0.001 ) but not in women ( not significant ) . In contrast , both genders exhibited an age-related quadratic decline in leg MQ as determined by Con PT ( approximately 40 % ) and Ecc PT ( approximately 25 % ; both P < 0.001 ) , and the rate of decline was similar for men and women . Thus MQ is affected by age and gender , but the magnitude of this effect depends on the muscle group studied and the type of muscle action ( Con vs. Ecc ) used to assess strength
Conclusions : Age-related differences support the impact of stroke-related sarcopenia as a contributor to hemiparetic muscle dysfunction .
Abstract Background : Despite extensive study of the impact of stroke on muscle and functional performance , questions remain regarding the extent to which changes are due to the neurological injury vs. age-related loss of morphology and force production .
Objectives : To synthesize available evidence describing post-stroke changes in lower extremity muscle size and strength compared to healthy adults .