ANKLE JOINT FOOT DORSIFLEXION AND INVERSION (TIBIALIS ANTERIOR) Muscle Tested: Tibialis Anterior - Origin: a) Lateral condyle and proximal ½ of lateral surface of tibia. b) Interosseus membrane, deep fascia and later inter-muscular septum. - Insertion: a) Medial and plantar surface of medial cuneiform bone. b) Base of first metatarsal bone. - Nerve Supply: Peroneal Nerve: L4, L5, S1. - Action: a) Dorsi flexes the ankle joint. b) Assists in inversion of the foot. Range of Motion: The range of motion of the ankle dorsiflexion is of 20o. The range of motion may be limited by: a) Tension of the lateral tarsal ligament. b) Tension of peroneus longus and peroneus brevis muscles. c) Contact between tarsal bones, medially. Test Procedures: * Grade 3 and 2 “Fair and Poor Strength”: - Patient Starting Position: Sitting with legs over the edge of table. - Therapist Position and Grasps: Sitting on a stool near the affected leg. The proximal hand grasps around the ankle to stabilize the lower leg. - Command: “Pull your foot up and in through full range of motion, Relax”. In grade 3, full ROM is requested while in grade 2; partial range of motion is requested. * Grade 4 and 5 “Good and Normal Strength”: - Patient Starting Position: Same as for Grade 3; the heel is supported on the thigh of therapist. - Therapist Position and Grasps: Same as for Grade 3 and 2. Proximal hand supports the lower leg above calcaneus, while distal hand grasps the medial border of forefoot to give resistance. - Resistance: Moderate and maximum resistance will be given in a form of pushing down the medial border of the foot. Note: Patient should keep big toe flexed to avoid substitution by extensor hallucis longus. - Command: “Pull your foot up through full range of motion up and in, Relax”. Note: A “hold” position is kept at the end of the range of motion when testing for “grade 5”. * Grade 1 and 0 “Trace and Zero Strength”: - Patient Starting Position: Back lying, foot over edge of table. - Therapist Position and Grasps: Standing near the edge of the table, distal hand supports the forefoot, while the proximal hand palpates contraction of tibialis anterior on its tendon on medial volar aspect of ankle. - Command: “Try to pull your foot up and in, Relax”. Effects of Weakness of the Tibialis Anterior Muscles: Weakness of the Tibialis Anterior Muscle decreases the ability to dorsi flex the ankle joint and allows tendency toward eversion of the foot. Substitution: The extensor Hallucis longus muscle, which has the function of assisting the dorsiflexion with inversion motion, may substitute to a weak tibialis anterior muscle. FOOT DORSIFLEXION AND INVERSION (TIBIALIS ANTERIOR) Grade 2, 3: Fair and Poor Strength Grade 4, 5: Good and Normal Strength Grade 1 , 0 : Trace and Zero Strength FOOT INVERSION FROM PLANTAR FLEXION (TIBIALIS POSTERIOR) Muscle Tested: 1. Tibialis Posterior: - Origin: a) Most of interosseus membrane. b) Lateral portion of posterior surface of tibia. c) Proximal 2/3 of medial surface of fibula. d) Adjacent inter-muscular septa and deep fascia. - Insertion: a) Tuberosity of navicular bone. b) By fibrous expansions to the sustentaculum tali of calcaneus three cuneiforms, cuboid and bases of second, third and fourth metatarsal bones. - Nerve Supply: Tibial Nerve: L4, L5, S1. - Action: a) Inverts the foot. b) Assists in the plantar flexion of the ankle joint. Accessory Muscles: 1. Flexor digitorum longus. 2. Flexor hallucis longus. 3. Gastrocnemius “medial head”. Range of Motion: The range of motion of foot inversion is of 35o. This range may be limited by: a) Tension of lateral tarsal ligaments. b) Tension of peroneal muscle group. c) Contact between tarsal bones medially. Test Procedures: * Grade 3 “Fair Strength”: - Patient Starting Position: Side lying affected leg down, foot in plantar flexion and resting on lateral border. - Therapist Position and Grasps: Standing at the foot of the table, proximal hand is placed proximal to ankle joint to stabilize the lower leg (Avoid pressure over tibialis posterior muscle). - Command: “Raise medial border of your foot up through full range of motion, Relax”. * Grade 4 ”Good Strength”: - Patient Starting Position: Same as for “Grade 3”, but with the foot over edge of table. - Therapist Position and Grasps: Same as for “Grade 3” the proximal hand supporting the lower leg proximal to ankle without pressure over tibialis posterior muscle, the distal hand over the medial border of the foot to give resistance. - Resistance: Moderate leading resistance is given directly opposing the line of motion. - Command: Same as for “Grade 3”. * Grade 5 “Normal Strength”: - Same procedures as for “Grade 4” but maximal resistance is applied and a “hold position” is performed at the end of the range of motion. * Grade 2 “Poor Strength”: - Patient Starting Position: Back lying with foot in plantar flexion over the end of the table. - Therapist Position and Grasps: Standing at the foot of the table near the affected foot and proximal hand grasping the leg posteriorly just above the ankle joint. - Command: “Move your foot medially, Relax”. * Grade 1 and 0 “Trace and Zero Strength”: - Patient Starting Position: Same as for Grade 2. - Therapist Position and Grasps: Same as for “Grade 2” but the distal hand palpates tendon of tibialis posterior between medial malleolus and navicular bone, contraction of tibialis posterior may be palpated above medial malleolus. MANUAL MUSCLE TESTING FOR FOOT INVERSION FROM PLANTAR FLEXION (TIBIALIS POSTERIOR) Grade 3: Fair Strength Grade 4, 5: Good and Normal Strength Grade 1, 0: Trace and Zero Strength FOOT EVERSION FROM PLANTAR FLEXION (PERONEUS LONGUS AND BREVIS) Muscle Tested: 1. Peroneus Longus: - Origin: a) Lateral condyle of tibia. b) Head and proximal 2/3 of lateral surface of fibula. c) Inter-muscular septa, an adjacent deep fascia. - Insertion: Lateral side of base of first metatarsal and medial cuneiform bone. - Nerve Supply: Peroneal Nerve: L4, L5, S1. - Action: a) Everts the foot. b) Assists in plantar flexion of the ankle joint. 2. Peroneus Brevis: - Origin: a) Distal 2/3 of lateral surface of fibula. b) Adjacent inter-muscular septa. - Insertion: Tuberosity at base of fifth metatarsal bone, lateral side. - Nerve Supply: Peroneal Nerve: L4, L5, and S1. - Action: Everts the foot and assists in plantar flexion of the ankle joint. Accessory Muscles: 1. Extensor digitorum longus. 2. Peroneus Tertius. Range of Motion: The range of motion of the foot eversion is of 35o. This range may be limited by: a) Tension of medial tarsal ligaments. b) Tension of tibialis anterior and Tibialis posterior muscles. c) Contact of tarsal bones laterally. Test Procedure: * Grade 3 “Fair Strength”: - Patient Starting Position: Side lying, the upper leg is the affected, foot over edge of bed and in plantar flexion; the leg is resting on its medial border. - Therapist Position and Grasps: Therapist is standing beside the foot of the table, the proximal hand support the lower leg proximal to the ankle joint. - Command: “Pull your foot up through full range of motion, Relax”. * Grade 4 “Good Strength”: - Patient Starting Position: Same as for “Grade 3”. - Therapist Position and Grasps: Same as for “Grade 3” the proximal hand stabilizes leg, the distal hand grasps the forefoot to give resistance. - Resistance: Moderate leading resistance is given to test peroneus brevis on lateral border of foot. To test peroneus longus, resistance is given against plantar surface of first metatarsal head. They may be tested together. Note: Extensor digitorum longus should be relaxed. - Command: “Raise the lateral border of the foot up through full range of motion, Relax”. * Grade 5 “Normal Strength”: Same procedures as for “Grade 4” but maximal resistance are used, with a “hold position” at the end of the range of motion. * Grade 2 “Poor Strength”: - Patient Starting Position: Side lying with the affected foot plantar flexed and resting on its medial border. - Therapist Position and Grasps: Therapist stands at the foot of the table. Proximal hand grasps the lower leg to stabilize it. - Command: “Pull your foot out with your small toe up and big toe down, Relax”. * Grade 1 and 0 “Trace and Zero Strength”: Same procedures as for “Grade 2” but the therapist distal hand palpates the tendon of peroneus brevis at a joint proximal to the base of the fifth metatarsal bone on the lateral border of the foot. Contraction of peroneus longus may be palpated under head of the first metatarsal bone. Effects of Weakness of Peroneus Brevis and Longus: Weakness of these muscles leads to: a) Decreases the strength of eversion of the foot and plantar flexion of the ankle joint. b) Allows a varus position of the foot. c) Lessens the ability to rise on the toes. d) Decreases lateral stability of the foot. Effect of Contracture of Peroneus Longus and Brevis: Contracture of these muscles results in an everted or valgus position of the foot. MANUAL MUSCLE TESTING FOR FOOT EVERSION FROM PLANTAR FLEXION (PERONEUS LONGUS AND BREVIS) Grade 3 - Fair Strength Grade 4, 5 – Good and Normal Strength Grade 1, 0: Trace and Zero Strength