Guide or ask the patient to sit down. With the patient relaxed and with permission, place your fingers on the plantar foot along the first metatarsal bone and ask the patient to flex the hallux or if not possible to isolate the hallux, to flex the toes. This muscle action produces a muscle contraction, which may be palpated on the plantar foot along the medial and lateral aspects of the plantar surface of the first metatarsal. Palpation of the tendon to the hallux is palpable on the medial and lateral aspects of the first metatarsophalangeal joint as the hallux flexes and then relaxes. The tendons insert on the medial aspect of the hallux with the abductor hallucis tendon and on the lateral aspect of the hallux with the adductor hallucis tendon.
With unclear muscle activity, increase the contraction of the flexor hallucis brevis by asking the patient to flex the hallux while you provide a push on this toe in the direction of hallux extension.