Both the peroneus brevis and longus tendons lie proximally in a common synovial sheath that extends from approximately 4 cm proximal to the tip of the lateral malleolus, to 1 cm distal to it (Fig. 1). The brevis tendon is relatively flat, running directly posterior to the distal fibula.Click to see full answer. Besides, how far up the leg does the peroneal tendon go?There are two peroneal tendons in each leg. They run side by side down the lower leg bone (fibula) and behind the bony lump on the outside of the ankle called the lateral malleolus. One peroneal tendon attaches to the outside of the foot at the base of the little toe (fifth metatarsal).Similarly, what does a peroneal tendon tear feel like? Symptoms can vary, but typically present as pain and swelling along the lateral aspect of the ankle. There may also be a feeling of ankle weakness or instability, especially when pushing off of the toes. In cases of subluxation, a snapping sensation along the outside of the ankle will be felt while walking. Considering this, where do the peroneal tendons insert? The peroneal tendons emerge from the peroneal tendon sheath at the inferior and posterior aspects of the fibula (Fig. 36.4A). The peroneus brevis then inserts on the tuberosity of the fifth metatarsal while the peroneus longus crosses under the cuboid on the way to its insertion on the base of the first metatarsal.Does peroneal tendonitis show on MRI?MRI is a useful diagnostic tool for detecting peroneal tendinopathy in patients with chronic lateral ankle instability. However, MRI is vague in many cases.