Knee flexor and extensor torque ratio in elderly men and women with and without obesity: a cross-sectional study
Valentina Muollo1, Andrea Zignoli2, Laura Ghiotto3
1Department of Medicine, University of Verona, Via Felice Casorati 43, 37131, Verona, Italy. valentina.muollo@univr.it.
Background:
With aging and obesity lower limb torque deteriorates. Importantly, the ratio between knee flexor (KF) and extensor (KE) torque is an indicator of joint stability.
Aims:
We compared KF torque and KF/KE ratio in older subjects of both sexes with obesity (OB) or without (NOB) obesity.
Methods:
The maximal torque during KE and KF isokinetic contractions were evaluated at: 60, 90, 150, 180 and 210 deg/s in 89 elderly (68 ± 5 years) subjects with NOB (BMI < 30 kg/m2) and OB (BMI ≥ 30 kg/m2). Values were normalised for body weight (BW) and leg lean mass (i.e., muscle quality).
Results:
At all speeds men had higher absolute KF values (P < 0.001). When values were normalised for BW, sex differences remain in favour of men (P < 0.001) with lower values in both groups with OB than NOB (P < 0.001). Muscle quality and KF/KE ratio were lower in OB than NOB (P < 0.001).
Conclusions:
The KF torque and KF/KE ratio decline with aging and with OB. In all groups, the KF/KE ratio was below the joint stability threshold. Thus, exercise physiologists should include exercises designed to train both KE and KF in older subjects with OB.
