Muscle knots in the Peroneus Longus (upper) are typically found along the outer side of the lower leg, just below the knee and extending toward the ankle. These muscle knots often refer pain to the outside calf, outer ankle, and even the arch of the foot, sometimes mimicking ankle sprains or plantar fasciitis. Muscle knots in the Peroneus Brevis (lower) are located lower on the leg, closer to the ankle, and can refer pain to the lateral ankle joint and the outer edge of the foot, especially around the base of the pinky toe. You may feel a sharp or aching discomfort when walking on uneven surfaces or after rolling the ankle.