Mass, fibre length and maximal muscles forces of the five large muscle complexes in the skull
| . | Adductor mandibulae complex . | Pterygoid muscles . | Depressor mandibulae . | Protractor quadratum . | Adductor quadratum complex . |
|---|---|---|---|---|---|
| Struthio (N=3) | |||||
| Mass (g) | 4.2±0.9 (6) | 6.8±0.7 (6) | 6.4±0.9 (6) | 1.0±0.2 (6) | 2.3±0.1 (6) |
| 2.6±0.2 (6) | |||||
| Fibre length (mm) | 16.4±4.6 (6) | 16.6±4.2 (6) | 44.0±11.4 (6) | 7.6±2.4 (5) | 12.4±4.7 (6) |
| 14.8±5.3 (6) | |||||
| Maximal force (N) | 96±48 (6) | 147±57 (6) | 51.5±15.7 (6) | 47±24 (5) | 72±36 (6) |
| 68±31 (6) | |||||
| Total max. force (N) | 164 | ||||
| Dromaius (N=2) | |||||
| Mass (g) | 1.9±0.1 (4) | 4.0±0.1 (4) | 3.8±0.0 (4) | 1.2±0.0 (4) | 1.8±0.1 (4) |
| 1.1±0.0 (4) | |||||
| Fibre length (mm) | 16.0±1.2 (4) | 18.8±0.6 (4) | 24.4±0.3 (4) | 9.0±0.6 (4) | 17.5±0.4 (4) |
| 12.5±0.5 (4) | |||||
| Maximal force (N) | 40±3.9 (4) | 70±0.5 (4) | 51±0.1 (4) | 43±3.0 (4) | 35±0.5 (4) |
| 28±0.0 (4) | |||||
| Total max. force (N) | 68 | ||||
| Rhea (N=2) | |||||
| Mass (g) | 2.2±0.2 (4) | 3.2±0.4 (4) | 2.0±0.2 (4) | 0.5±0.3 (2) | 0.6±0.4 (4) |
| 1.4±0.1 (4) | |||||
| Fibre length (mm) | 9.1±0.3 (4) | 8.7±0.9 (4) | 28.1±2.8 (4) | 5.4±1.2 (4) | 5.8±1.2 (4) |
| 4.8±1.1 (4) | |||||
| Maximal force (N) | 80±8.5 (4) | 123±24 (4) | 23.9±4.7 (4) | 36±13 (2) | 32±15 (4) |
| 95±25 (4) | |||||
| Total max. force (N) | 175 |
| . | Adductor mandibulae complex . | Pterygoid muscles . | Depressor mandibulae . | Protractor quadratum . | Adductor quadratum complex . |
|---|---|---|---|---|---|
| Struthio (N=3) | |||||
| Mass (g) | 4.2±0.9 (6) | 6.8±0.7 (6) | 6.4±0.9 (6) | 1.0±0.2 (6) | 2.3±0.1 (6) |
| 2.6±0.2 (6) | |||||
| Fibre length (mm) | 16.4±4.6 (6) | 16.6±4.2 (6) | 44.0±11.4 (6) | 7.6±2.4 (5) | 12.4±4.7 (6) |
| 14.8±5.3 (6) | |||||
| Maximal force (N) | 96±48 (6) | 147±57 (6) | 51.5±15.7 (6) | 47±24 (5) | 72±36 (6) |
| 68±31 (6) | |||||
| Total max. force (N) | 164 | ||||
| Dromaius (N=2) | |||||
| Mass (g) | 1.9±0.1 (4) | 4.0±0.1 (4) | 3.8±0.0 (4) | 1.2±0.0 (4) | 1.8±0.1 (4) |
| 1.1±0.0 (4) | |||||
| Fibre length (mm) | 16.0±1.2 (4) | 18.8±0.6 (4) | 24.4±0.3 (4) | 9.0±0.6 (4) | 17.5±0.4 (4) |
| 12.5±0.5 (4) | |||||
| Maximal force (N) | 40±3.9 (4) | 70±0.5 (4) | 51±0.1 (4) | 43±3.0 (4) | 35±0.5 (4) |
| 28±0.0 (4) | |||||
| Total max. force (N) | 68 | ||||
| Rhea (N=2) | |||||
| Mass (g) | 2.2±0.2 (4) | 3.2±0.4 (4) | 2.0±0.2 (4) | 0.5±0.3 (2) | 0.6±0.4 (4) |
| 1.4±0.1 (4) | |||||
| Fibre length (mm) | 9.1±0.3 (4) | 8.7±0.9 (4) | 28.1±2.8 (4) | 5.4±1.2 (4) | 5.8±1.2 (4) |
| 4.8±1.1 (4) | |||||
| Maximal force (N) | 80±8.5 (4) | 123±24 (4) | 23.9±4.7 (4) | 36±13 (2) | 32±15 (4) |
| 95±25 (4) | |||||
| Total max. force (N) | 175 |
The Adductor mandibulae complex consists of two parts with unequal fibre lengths but with similar lines of action. The total force of these parts is combined as `Total max. force'.
Values of both mass and fibre lengths are means (number of muscles used).