Function. Primarily, the extensor digitorum communis extends medial four digits at the metacarpophalangeal joints and secondarily at the interphalangeal joints. It also acts to extend the wrist joint.
The primary action of the extensor digitorum longus is to extend the lateral four toes at metatarsophalangeal joint. This means that when acting independently, it is unable to extend the entire length of the toes, extending only at metatarsophalangeal, while at the interphalangeal joints the toes remain flexed.
Sit up straight in a chair and with your feet flat on the floor. Take your left foot upward and place it comfortably on the thigh of your right leg. Then, use your fingers to gently stretch the big toe up, down, and to the sides. Continue to do this for 10 seconds and repeat 10 times.
Extensor tendonitis: This is caused by overuse or tight-fitting shoes. The tendons that run along the top of the foot and pull the foot upwards become inflamed and painful.
In the hand these include the extensor carpi radialis brevis, extensor carpi radialis longus, and extensor carpi ulnaris, which run from the humerus (bone of the upper arm) along the back of the forearm to the metacarpal bones at the back of the hand and which extend the wrist; the extensor digitorum, which runs from
The function of the extensor digitorum brevis is to extend or straighten the middle three toes when the foot is fully dorsiflexed.
The extrinsic extensor muscles of the hand are located in the back of the forearm and have long tendons connecting them to bones in the hand, where they exert their action. Extrinsic denotes their location outside the hand. Extensor denotes their action which is to extend, or open flat, joints in the hand.
There are three flexors, and one extensor. The three flexors are brachialis, biceps, and brachioradialis. Here's the brachialis muscle.
The key difference between flexor and extensor muscles is that flexor muscles facilitate the process of flexion in the body, while extensor muscles facilitate the process of extension in the body. On the other hand, extension is the extending movement where the angle between two body parts increases.
The goal of treatment is to reduce irritation, inflammation, and pain in the top of the foot.Treatment may include:
- Rest to allow the tendon to heal.
- Ice to reduce pain and inflammation.
- NSAIDs or Acetaminophen to reduce pain and inflammation.
- Shoelace technique to avoid pressure on the tender areas.
The talus is the top (most proximal) bone of the foot. Because it articulates with so many other bones, 70% of the talus is covered with hyaline cartilage (joint cartilage).
Muscles and JointsThe extensor muscle relaxes and stretches as the flexor muscle contracts to bend the joint. The flexor relaxes and the extensor contracts to straighten (or extend) the limb at the same joint. Muscles get their signals to contract and relax from the brain.
The tendon of peroneus tertius passes under the extensor retinaculum, and in front of the lateral malleolus to insert here, on the base of the fifth metatarsal, next to peroneus brevis. The action of all three of the peroneal muscles is to evert the foot.
