The Company of Biologists

Table 1.

A range of muscles with similar roles from animals of different size and their properties

Muscle type	P_o (N)	L_o (mm)	Stiffness (N mm^-1)	Relative stiffness (P_oL_o)
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

Muscle type	P_o (N)	L_o (mm)	Stiffness (N mm^-1)	Relative stiffness (P_oL_o)
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).