Peroneal tendon synovitis can develop due to overuse. However sometimes acute injury such as plantarflexion inversion can cause a longitudinal split in the peroneus brevis tendon. A period of rest and physiotherapy is helpful.
Peroneal tendon subluxation or dislocation can happen with forced dorsiflexion which tears the retinaculum and allows the tendon to move superficial to the lateral malleolus. This condition is difficult to treat conservatively and often requires surgery which involves deepening the fibular groove and reconstruction of the peroneal retinaculum.