| Healthy(n = 26) | COPD(n = 30) | Mean difference (95% CI) | Mean difference (% of mean value in healthy subjects) | p Value | |
| RFCSA (mm2) | 463 (137) | 348 (78) | −115 (−177 to −54) | −25 | 0.001 |
| QMVC (kg) | 35.6 (11.9) | 26.3 (9.9) | −9.3 (−15.1 to −3.4) | −26 | 0.002 |
| TwQ (kg) | 8.0 (2.4) | 6.2 (1.7) | −1.8 (−3.0 to −0.6) | −23 | 0.004 |
| QMVC/RFCSA (g/mm2) | 77.7 (16.8) | 74.5 (17.6) | −3.2 (−12.4 to +6.1) | −4 | 0.493 |
| TwQ/RFCSA (g/mm2) | 17.4 (3.9) | 17.9 (3.3) | +0.5 (−1.6 to +2.5) | +3 | 0.657 |
Data shown as mean (SD). p Values derived from unpaired t tests. TwQ results reflect supramaximal responses only.
QMVC, quadriceps maximum voluntary contraction; RFCSA, rectus femoris cross-sectional area; TwQ, quadriceps twitch tension.