Table 3.

Comparison between measurements and muscle masses calculated from the 3D models for the gorilla.

	Measured mass (kg)	Modelled volume (cm3)	Modelled mass (kg)	Difference (%)	LoA length (cm)
M. deltoideus clavicularis	0.063	65.405	0.069	9.576	25.434
M. deltoideus acromialis	0.166	140.047	0.148	− 10.669	21.325
M. deltoideus spinalis	0.057	51.387	0.054	− 4.001	19.733*
M. deltoideus (combined)	0.286	256.839	0.272	− 4.871	–
M. supraspinatus	0.084	79.440	0.084	0.305	15.539
M. infraspinatus	0.105	99.730	0.106	0.843	15.747
Total	0.475	436.008	0.462	− 2.695	–

The length of the muscle was measured along the LoA (arc length) of the modelled muscles and represents the length from origin to insertion and thus the total length of the muscle tendon unit (MTU).

*Note the length of the M. deltoideus spinalis was exaggerated due to the kink in the LoA estimation (see Fig. 3d).