उरसा शिरसा दृष्ट्या मनसा वचसा तथा ।
पद्भ्यां कराभ्यां जानुभ्यां प्रणामोऽष्टाङ्ग उच्यते ॥

Meaning:
The bowing with the chest, head, eyes, mind, speech, feet, and knees, is called the eight-fold salution.

Word meanings:
उरसा = by the chest;
शिरसा = by the head;
दृष्ट्या = through sight (F.instr.);
मनसा = through the mind;
वचसा = through words;
तथा = like that (cf. yathA tathA);
पद्भ्यां = through the or to the or from the two feet;
कराभ्यां = through the or to the or from the 2 hands;
जानुभ्यां = through the or to the or from the two knees;
प्रणमोऽष्टाङ्ग = bowing by 8 parts of the body (touching the ground);