A stress fracture in the heel is a common injury resulting from repetitive overuse. It is a small crack or micro-trauma within a bone, caused when the bone’s capacity to repair itself is overwhelmed by repeated forces. Unlike a sudden, traumatic fracture, this type of injury develops gradually over time.
The Calcaneus Bone and Stress Fractures
The heel bone, known as the calcaneus, is the largest bone in the foot and forms the foundation of the rear part of the foot. It is susceptible to stress fractures because it absorbs a significant amount of the axial load and impact with every step, run, or jump.
The bone is structured with a thin, hard outer shell surrounding a softer, spongy interior, similar to a hardboiled egg. This structure is highly efficient for absorbing compressive forces from body weight, but it is less adept at handling the repetitive tensile and shearing loads that occur during high-impact activities. When these forces exceed the bone’s ability to remodel and strengthen itself, the micro-damage accumulates, eventually leading to a stress fracture.
Recognizing the Signs of a Heel Stress Fracture
The most common symptom of a calcaneal stress fracture is pain around the heel that develops gradually over days or weeks. This pain often increases with activity and tends to be relieved by rest. The discomfort is typically felt deep inside the heel bone, often localized on the back or bottom of the heel.
The pain can progress from only occurring during exercise to becoming constant, making normal walking difficult. Localized swelling and tenderness to the touch around the heel area are also common signs. A physical test where the heel bone is squeezed gently from the sides, known as the squeeze test, often reproduces the sharp pain associated with this fracture.
Common Triggers and Risk Factors
The primary trigger for a calcaneal stress fracture is the “too much, too soon” principle, involving a sudden, significant increase in the intensity, duration, or frequency of physical activity. Activities like long-distance running, jumping sports, or marching with heavy loads place excessive, repetitive forces on the heel bone, leading to micro-trauma. These injuries were historically called “Marcher’s Fractures” due to their prevalence in military recruits.
Improper or worn-out footwear is another factor, as shoes lacking adequate support or cushioning fail to absorb shock effectively. This transfers greater impact forces directly to the calcaneus. Biomechanical issues, such as excessively flat feet or high arches, can also alter foot mechanics and increase stress on specific areas of the heel. Low bone density from conditions like osteoporosis, or nutritional deficiencies in calcium and Vitamin D, compromise bone strength and increase vulnerability to these stress injuries.
Treatment and Healing Timeline
Diagnosis often requires advanced imaging like an MRI because initial X-rays can appear normal. Treatment focuses on removing stress from the injured bone through a non-operative approach. This requires a period of non-weight-bearing or restricted weight-bearing activities to allow the cracks to heal. Patients are typically instructed to use crutches or wear a walking boot to immobilize the foot and reduce load on the heel.
The initial recovery phase, involving rest and immobilization, commonly lasts for six to eight weeks. Applying ice and elevating the foot can help manage any residual swelling during this time. After the period of immobilization, a gradual return to activity is necessary to prevent re-injury, which can take an additional six to twelve weeks. Physical therapy may be recommended to restore strength and flexibility in the foot and ankle before resuming full, high-impact activities.