A range of muscles with similar roles from animals of different size and their properties
| Muscle type | Po (N) | Lo (mm) | Stiffness (N mm-1) | Relative stiffness (PoLo) |
|---|---|---|---|---|
| Hopping mouse gastrocnemius* | 3.6 | 7.3 | 7.7 | 15.61 |
| Rat gastrocnemius* | 11.3 | 13.8 | 15.9 | 19.41 |
| Human gastrocnemius† | 875 | 65 | 150 | 11.14 |
| Wallaby gastrocnemius* | 135 | 18.7 | 21 | 2.91 |
| Horse superficial digital flexor‡ | 716 | 7.5 | 118 | 1.23 |
The calculated relative stiffness is normalised to muscle fibre length and maximum isometric muscle force.
↵* Data from Ettema (1996); †data from Maganaris and Paul (2002); ‡data from Swanstrom et al. (2005) and Brown et al. (2004).