Contractile properties of the SUPRA and PECT muscles in pigeons(Columba livia) during different modes of flight
| Variable . | Level . | Ascending . | Descending . | P . |
|---|---|---|---|---|
| SUPRA peak stress (kPa) | 96±48 | 125±65 | 85±30 | 0.0463 |
| SUPRA strain (ϵ) | 35±10 | 40±14 | 33±10 | 0.0039 |
| SUPRA fractional lengthening (%) | 7±6 | 12±8 | 6±5 | 0.0105 |
| SUPRA fractional shortening (%) | –27±7 | –27±6 | –27±6 | 0.0760 |
| SUPRA strain rate (L s–1) | 6±1 | 7±2 | 5±2 | 0.0042 |
| SUPRA net work (mJ) | 153±78 | 234±144 | 130±52 | 0.0145 |
| SUPRA positive work (mJ) | 180±93 | 273±167 | 164±66 | 0.0152 |
| SUPRA negative work (mJ) | –26±32 | –39±53 | –33±31 | 0.3381 |
| SUPRA mass-specific power (W kg–1) | 127±57 | 194±98 | 106±50 | 0.0178 |
| SUPRA energy recovery (mJ) | 51±62 | 88±85 | 35.8±29 | 0.0548 |
| PECT peak stress (kPa) | 53±15 | 58±15 | 50±12 | 0.0017 |
| PECT strain (ϵ) | 36±8 | 42±8 | 35±9 | 0.0008 |
| PECT fractional lengthening (%) | 28±7 | 28±7 | 26±8 | 0.3016 |
| PECT fractional shortening (%) | –8±3 | –14±4 | –9±5 | 0.0452 |
| PECT strain rate (L s–1) | 5±1 | 6±1 | 5±1 | 0.0023 |
| PECT net work (mJ) | 531±208 | 614±133 | 460±133 | 0.0267 |
| PECT positive work (mJ) | 642±228 | 748±181 | 587±155 | 0.0293 |
| PECT negative work (mJ) | –110±97 | –134±105 | –127±85 | 0.2297 |
| PECT mass-specific power (W kg–1) | 87±25 | 105±14 | 75±24 | 0.0124 |
| Variable . | Level . | Ascending . | Descending . | P . |
|---|---|---|---|---|
| SUPRA peak stress (kPa) | 96±48 | 125±65 | 85±30 | 0.0463 |
| SUPRA strain (ϵ) | 35±10 | 40±14 | 33±10 | 0.0039 |
| SUPRA fractional lengthening (%) | 7±6 | 12±8 | 6±5 | 0.0105 |
| SUPRA fractional shortening (%) | –27±7 | –27±6 | –27±6 | 0.0760 |
| SUPRA strain rate (L s–1) | 6±1 | 7±2 | 5±2 | 0.0042 |
| SUPRA net work (mJ) | 153±78 | 234±144 | 130±52 | 0.0145 |
| SUPRA positive work (mJ) | 180±93 | 273±167 | 164±66 | 0.0152 |
| SUPRA negative work (mJ) | –26±32 | –39±53 | –33±31 | 0.3381 |
| SUPRA mass-specific power (W kg–1) | 127±57 | 194±98 | 106±50 | 0.0178 |
| SUPRA energy recovery (mJ) | 51±62 | 88±85 | 35.8±29 | 0.0548 |
| PECT peak stress (kPa) | 53±15 | 58±15 | 50±12 | 0.0017 |
| PECT strain (ϵ) | 36±8 | 42±8 | 35±9 | 0.0008 |
| PECT fractional lengthening (%) | 28±7 | 28±7 | 26±8 | 0.3016 |
| PECT fractional shortening (%) | –8±3 | –14±4 | –9±5 | 0.0452 |
| PECT strain rate (L s–1) | 5±1 | 6±1 | 5±1 | 0.0023 |
| PECT net work (mJ) | 531±208 | 614±133 | 460±133 | 0.0267 |
| PECT positive work (mJ) | 642±228 | 748±181 | 587±155 | 0.0293 |
| PECT negative work (mJ) | –110±97 | –134±105 | –127±85 | 0.2297 |
| PECT mass-specific power (W kg–1) | 87±25 | 105±14 | 75±24 | 0.0124 |
SUPRA, supracoracoideus; PECT, pectoralis. Values are means ± s.d., N=7 (except ascending N=6), P value calculated using repeated measures ANOVA (d.f.=5,2)