Table 3a.

Origin, insertion and function of the extrinsic foot muscles of Pan paniscus

Muscles	Origin	Insertion	Form	Function
(a) Triceps surae
Gamed	short tendon at posterior side of the medial femoral condyle	common short Achilles tendon onto the posterior side of the tuber calcanei	large, unipennate with extensive tendon sheet at origin and insertion	foot plantar flexion
Galat	short tendon at posterior side of the lateral femoral condyle
Soleus	broad tendon at posterior side of the fibular head and the membrana interossea		large, unipennate with extensive tendon sheet at origin and insertion
Plant	short tendon at posterior side of the lateral femoral condyle		small, pennate; proximally fused with Galat
(b) Dorsiflexors
EDL	proximal 1/3 of the antero-medial side of the fibular shaft and the membrana interossea	4 tendons to the dorsal aponeuroses of digits II, III, IV and V	long, slender, unipennate	dorsiflexion of ankle and toes; foot eversion
EHL	middle 1/3 of the antero-medial side of the fibular shaft and the membrana interossea	tendon to dorso-medial side of the distal phalanx of digit I	thin, unipennate; tendon through lig. naviculare–metatarse I	extension and abduction of hallux; foot inverson
TA	antero-lateral side of tibial head and proximal 1/2 of the tibial shaft and the membrana interossea	2 separate tendons to medio-plantar side of the medial cuneiform and first metatarsal	bipennate; proximally divided in large and small muscle head	foot dorsiflexion and inversion
(c) Deep hind flexors
FT	proximal 1/3 of the posterior side of the tibial shaft	2 tendons to the plantar side of the distal phalanges of digits II and V	superficial, pennate head; tendons fused with FF tendons, m. lumbricale II, and FDB	digital flexion; foot plantar flexion
FF	proximal 1/2 of the posterior side of the fibular head and shaft and the membrana interossea	3 tendons to the plantar side of the distal phalanges of digits I, III and IV	deep, unipennate head; fused with FT tendons and mm. Lumbricales III, IV and V	hallucal and digital flexion; foot plantar flexion and inversion
(d) Invertors and evertors
TP	proximal 1/2 of the postero-lateral side of the tibia and the postero-medial of the fibula and the membrana interossea	strong tendon to plantar side of the medial cuneiform and naviculare	large, pennate	foot plantar flexion and inversion
Plong	antero-lateral side of the fibular head and prox. 1/2 of the fibular shaft	tendon to the plantar base of first metatarsal	bipennate; proximally fused with Pbrev	foot eversion and plantar flexion; hallucal flexion and adduction
Pbrev	distal 1/2 of the anterior side of the fibular shaft	tendon to the lateral tuberosity of metatarsal V	unipennate; proximally fused with Plong	foot eversion and plantar flexion