Table 1.

Force-generating parameters of the musculotendon units included in the hindlimb model.

Functional group	Musculotendon unit	Abbreviation	Fmax (N)	Lf (m)	Lts (m)	Pennation angle (°)
Hip rotators	Obturator externus	OE	0.086	0.00246	0.00096	0.00
	Obturator internus	OI	0.314	0.00565	0.00065	0.00
	Gemellus	GEM	0.179	0.00143	0.00001	0.00
	Quadratus femoris	QF	2.030	0.00465	0.00110	0.00
Hip adductors	Adductor magnus	AM	0.614	0.00760	0.00302	0.00
	Adductor longus	AL	0.402	0.00745	0.00255	0.00
	Adductor brevis	AB	0.234	0.00642	0.00176	0.00
	Gracilis posterior	GP	0.345	0.00912	0.00435	0.00
	Gracilis anterior	GA	0.402	0.00882	0.00607	0.00
Hip flexors	Psoas major	PMA	1.338	0.00697	0.00501	15.54
	Psoas minor	PMI	1.088	0.00578	0.00390	12.57
	Iliacus	ILI	0.549	0.00857	0.00275	0.00
	Pectineus	PECT	0.363	0.00277	0.00181	15.18
Hip extensors	Gluteus maximus (dorsal)	GM (d)	0.936	0.01305	0.00501	20.42
	Gluteus maximus (middle)	GM (m)	1.026	0.01271	0.00489	20.42
	Gluteus maximus (ventral)	GM (v)	1.049	0.01242	0.00478	20.42
	Caudofemoralis	CF	0.554	0.01137	0.00307	0.00
	Semimembranosus	SM	1.916	0.01165	0.00409	0.00
	Semitendinosus	ST	1.299	0.01111	0.00480	0.00
	Biceps femoris anterior	BFA	0.876	0.01145	0.00383	0.00
	Biceps femoris posterior (cranial)	BFP (cr)	0.725	0.01008	0.00491	0.00
	Biceps femoris posterior (middle)	BFP (m)	0.728	0.01004	0.00478	0.00
	Biceps femoris posterior (caudal)	BFP (ca)	0.611	0.01197	0.00406	0.00
Knee extensors	Rectus femoris	RF	4.162	0.00534	0.00853	15.89
	Vastus medialis	VM	1.098	0.00653	0.00768	16.15
	Vastus lateralis	VL	2.828	0.00681	0.00735	15.53
	Vastus intermedius	VI	0.367	0.00606	0.00702	10.92
Knee flexors	Popliteus	POP	0.307	0.00206	0.00203	0.00
Ankle dorsiflexors	Tibialis anterior	TA	2.422	0.00490	0.01180	16.58
	Extensor digitorum longus	EDL	0.368	0.00635	0.02378	12.39
	Extensor hallucis longus	EHL	0.069	0.00593	0.01793	9.56
Ankle plantarflexors	Medial gastrocnemius	MG	1.750	0.00550	0.01395	14.24
	Lateral gastrocnemius	LG	3.784	0.00541	0.01389	17.28
	Soleus	SOL	0.591	0.00316	0.00740	11.43
	Plantaris	PLANT	0.880	0.00431	0.01517	17.10
	Flexor digitorum longus	FDL	1.896	0.00431	0.02761	15.20
	Tibialis posterior	TP	0.549	0.00359	0.01500	15.44
Ankle everters	Peroneus longus	PL	0.647	0.00378	0.01408	14.90
	Peroneus tertius	PT	0.457	0.00339	0.01122	12.46
	Peroneus brevis	PB	0.396	0.00229	0.01005	11.46
	Peroneus digiti quarti	PDQA	0.112	0.00393	0.02357	12.42
	Peroneus digiti quinti	PDQI	0.102	0.00362	0.01959	9.44

Maximum force (F_max), fiber length (L_f), and pennation angle (°) were derived from previously measured skeletal muscle architecture (Charles et al., 2016a). Tendon slack length (L_ts) was estimated using a numerical optimization procedure from Manal and Buchanan (2004). Grouping was based on presumed functions during locomotion (Charles et al., 2016b).