Table 3

Muscle bundle characteristics and in vitro twitch contractile properties of vastus lateralis in both groups

ControlCOPD
Subjects n916
Lo mm15±315±4
Muscle bundle CSA mm24.4±3.14.6±2.1
TPT ms63±1266±11
RT½ ms80±2477±11
Pt g2.4±2.52.2±1.9
  • Data are presented as mean±sd

  • COPD: chronic obstructive pulmonary disease

  • Lo: optimal length at which maximal twitch tension is produced

  • CSA: cross-sectional area

  • TPT: time required to reach peak twitch tension

  • RT½: time required to reach half-relaxation after twitch contraction

  • Pt: maximal isometric twitch tension