The primary intrinsic muscles of the lower leg are Plantar flexors, Dorsiflexors, Absuctors. The intrinsic muscles are located within the foot, cause toe movements and help support the arches. Extrinsic muscles on the other hand are located outside the foot, in the lower leg, they have long tendons that cross the ankle and attach the bones of the foot, to assist movement. The extrinsic muscles are the extensor hallicus longus, the extensor digitorium longus, the fibularis tertius and the tibialis anterior.