Complex sentence: There it supplies one and a half muscles (flexor carpi ulnaris and the medial half of flexor digitorum profundus) and courses with the ulnar artery, travelling inferiorly together, deep to the flexor carpi ulnaris muscle.
Split into simpler sentences: There it supplies one and a half muscles (flexor carpi ulnaris and the medial half of flexor digitorum profundus). It soon joins with the ulnar artery, and the two travel inferiorly together, deep to the flexor carpi ulnaris muscle.