Yokote T; Koga H; Eriguchi K; Imamura Y;

Journal of physical therapy science [J Phys Ther Sci] 2020 Apr; Vol. 32 (4), pp. 265-268. Date of Electronic Publication: 2020 Apr 02.

[Purpose] The mortality rate increases when peak oxygen uptake is less than 5 metabolic equivalents, and peak oxygen uptake correlates with knee extensor muscle strength. This study aimed to determine the knee extensor muscle strength at peak oxygen uptake corresponding to 5 metabolic equivalents.
[Participants and Methods] We enrolled 45 consecutive patients (29 males and 16 females; average age, 63.6 ± 13.7 years) with heart disease receiving outpatient rehabilitation with us. We performed cardiopulmonary exercise testing with a bicycle ergometer to measure peak oxygen uptake. We investigated the relationship between peak oxygen uptake and isometric knee extensor muscle strength divided by the body weight (kgf/kg). The cutoff value for knee extensor muscle strength with peak oxygen uptake corresponding to 5 metabolic equivalents was calculated.
[Results] Knee extensor muscle strength was significantly positively associated with peak oxygen uptake. The cutoff value for knee extensor muscle strength at peak oxygen uptake corresponding to 5 metabolic equivalents was 0.46 kgf/kg.
[Conclusion] In this study, the cutoff value for knee extensor muscle strength for achieving peak oxygen uptake corresponding to 5 metabolic equivalents in patients with heart disease was 0.46kgf/kg.