Stress Fractures – Symptoms and Causes
What Are Stress Fractures?
Stress fractures are small cracks that form in bones due to repeated pressure or force. Unlike regular broken bones from a single injury, these tiny breaks happen over time from doing the same movements again and again.
These fractures most commonly affect the bones in the lower leg and foot that carry your body weight. People who run track, compete in field events, or serve in the military often get these injuries.
Military members may develop them from walking long distances while carrying heavy equipment.
Anyone can get a stress fracture, though. Even starting a new workout routine too intensely can lead to these small bone breaks. Conditions that weaken bones, like osteoporosis, can also make stress fractures more likely to happen during normal activities.
Signs and Symptoms
Stress fractures often start with mild pain that gets worse during physical activity. You might notice pain that improves with rest but returns when you resume activities.
The injured area may become swollen or tender to touch. Some people experience bruising in the affected spot.
Many stress fractures occur in weight-bearing bones of the foot and leg. Common locations include the metatarsal bones (the long bones in your foot), the heel, the shin bone, and hip bones.
Pain typically develops gradually rather than suddenly. You might feel it only during certain activities at first, then notice it becomes more constant.
When to Visit a Doctor
See a doctor if you experience pain that:
- Doesn’t improve with rest
- Gets worse despite reducing activity
- Continues even when you’re not putting weight on the area
- Is accompanied by significant swelling or bruising
If you have pain in your feet or legs while exercising, stop the activity and rest. Apply ice and elevate the injured area. If symptoms don’t improve within a few days, make an appointment with your healthcare provider.
What Causes Stress Fractures?
Stress fractures happen when bones experience repeated force over time. Unlike regular fractures that occur from single impacts, these tiny cracks develop gradually from ongoing stress.
Physical activity is the main culprit behind stress fractures. When muscles become tired, they transfer stress to bones. This commonly affects the weight-bearing bones in the lower leg and foot.
Common causes include:
- Sudden Increases in Activity: Starting a new exercise routine too intensively or increasing workout duration too quickly.
- Change in Surface: Shifting from soft surfaces like grass to harder surfaces like concrete.
- Poor Equipment: Worn-out or improper footwear that doesn’t provide enough support.
- Incorrect Technique: Moving in ways that put extra stress on certain bones.
Risk Factors
People who face a higher chance of developing stress fractures often share certain traits or habits. Physical activity level plays a major role, with runners, dancers, gymnasts, and military recruits being particularly at risk due to repetitive impact on their bones.
People who exercise for long periods without adequate rest may also develop these injuries more frequently.
Bone health factors contribute substantially to stress fracture risk:
- Low bone density
- Osteoporosis
- Previous stress fractures
- Family history of bone issues
Foot mechanics and footwear matter too. People with flat feet, high arches, or stiff feet have unusual weight distribution patterns that may increase stress on certain bones. Worn-out athletic shoes don’t absorb shock effectively, transferring more impact to the skeleton.
Nutrition plays a crucial role in bone health and stress fracture prevention. Several nutritional factors increase risk:
| Nutritional Factor | How It Affects Risk |
|---|---|
| Low calcium intake | Weakens bone structure |
| Vitamin D deficiency | Reduces calcium absorption |
| Eating disorders | Lead to bone mineral loss |
| Low calorie diets | Insufficient nutrients for bone repair |
Women face additional risks due to hormonal factors, particularly those with irregular menstrual cycles or absent periods, which can lower estrogen levels and affect bone density.
Medical conditions that affect bone strength can contribute too. These include osteoporosis, certain medications, and hormonal imbalances that impact bone density.
Possible Complications
Stress fractures can lead to several problems if left untreated. The bone may break completely, requiring surgery and longer healing time. For athletes, continuing to exercise with a stress fracture often worsens the injury and extends recovery.
Some bones, like those in the foot, hip, and lower leg, have areas with poor blood supply. Stress fractures in these spots heal slowly and sometimes incompletely.
The navicular bone in the foot and the fifth metatarsal are particularly prone to healing problems.
Chronic pain may develop if stress fractures don’t heal properly. This pain might persist even after the initial injury seems better, limiting physical activity long-term.
People with certain risk factors face greater chances of complications. These include those with osteoporosis, nutritional deficiencies, or hormonal imbalances that affect bone health.
Women with irregular menstrual periods may experience slower healing due to lower estrogen levels that affect bone density.
Prevention
Taking steps to prevent stress fractures can save you from pain and downtime.
Regular exercise that gradually increases in intensity helps your bones adapt to new stresses. Proper footwear with good support and cushioning reduces impact forces on your bones.
Nutrition plays a key role in prevention.
Getting enough calcium (1,000-1,200 mg daily) and vitamin D (600-800 IU daily) strengthens your bones. Women with irregular periods should talk to their doctor, as hormonal issues can weaken bones.
Rest and recovery strategies:
- Take at least 1-2 days off between high-impact workouts
- Cross-train with low-impact activities like swimming or cycling
- Replace athletic shoes every 300-500 miles of use
Listen to your body and don’t ignore pain that persists during activity.
For runners and athletes, increasing training intensity by no more than 10% per week helps bones adapt safely. This “10% rule” reduces the risk of developing stress fractures while still allowing for progress in your fitness routine.
