Table 1.

Information provided by cited articles about age-related reduction in muscle force

Ref.	Age-related reduction in muscle force/torque	Age of participants, yr	Testing condition	Physical activity level
Baroni et al[171]	30%-36% 40%-53%	y: 30 ± 6 o: 69 ± 5 yr	Isometric KE Concentric KE (60-360º/s)	No systematic training No systematic training
Laudani et al[173]	36.9%	y: 28 ± 2 o: 70 ± 3	Isometric KE	Sedentary adults
Karamanidis et al[169]	21% 18.9%	y: 21-32 o: 60-69	Isometric KE Isometric KE	Endurance runners Not active
Mademli et al[170]	28%	y: 30 ± 7 o: 65 ± 3	Isometric KE	Physically active
Savelberg et al[172]	33% 43%	y: 23 ± 2 o: 65 ± 3	Isometric KE Isometric KF	Active runners Active runners
Macaluso et al[174]	17% 30%	y: 23 ± 6 o: 70 ± 2	Isometric KE Isometric KF	Active Active
Frontera et al[195]	15.5%-22% 17%-23%	12-yr longitudinal study, initial mean age 65 ± 2	Isokinetic KF (60 and 240º/s) Isokinetic KE (60 and240º/s)	Healthy Healthy

KE: Knee extension; KF: Knee flexion; Y: Young; O: Old.