Stress fractures are one of the most frustrating injuries for runners. They often appear gradually, forcing athletes to stop running for 6–12 weeks or longer while the bone heals. Among runners, the tibia (shin bone) is the most common location for stress fractures.
But why do some runners develop stress fractures while others running similar mileage stay injury-free? Research suggests that how you run — not just how much you run — may play an important role.
A study published in the Journal of Orthopaedic & Sports Physical Therapy examined the running mechanics of female distance runners with and without a history of tibial stress fractures.
Two Key Differences in Running Mechanics
The study found two biomechanical patterns that were more common in runners with a history of tibial stress fracture.
1. Increased Hip Adduction
Runners with stress fractures tended to show greater inward movement of the thigh (hip adduction) during the stance phase of running. This movement pattern can cause the knee and lower leg to shift inward, potentially altering how forces are distributed through the tibia.
2. Greater Rearfoot Eversion (Overpronation)
The same runners also showed greater rearfoot eversion, which is often described as increased pronation of the foot. When the foot rolls inward excessively, it may increase torsional forces through the tibia, potentially contributing to repetitive bone stress.
Why These Mechanics Matter
Bones adapt well to normal training loads. However, repetitive loading combined with subtle movement changes can gradually increase stress on specific tissues.
The researchers suggested that these running mechanics may change how forces travel through the lower leg, possibly increasing the risk of fatigue damage to the tibia over time.
Even small differences — only a few degrees of joint motion — may influence how stress accumulates across thousands of running steps.
The findings suggest that running mechanics may be one piece of the injury puzzle.
Other factors also influence stress fracture risk, including:
- Training volume and intensity
- Recovery time
- Nutrition and bone health
- Muscle strength and fatigue
- Running surface and footwear
What Runners Can Do to Reduce Injury Risk
The encouraging part is that running mechanics can be assessed and improved. Research suggests that several strategies may help address these biomechanical factors:
- Strengthening the hips
- Improving foot and ankle control
- Gait retraining
- Running assessments
How Aureum Physio Helps Runners
At Aureum Physio, we use a comprehensive evaluation approach for runners that includes:
- Running gait assessment
- Hip and lower-extremity strength testing
- Mobility and movement screening
- Injury risk analysis based on current research
From there, we build individualized programs to improve running mechanics, reduce injury risk, and enhance performance.
If you’re dealing with shin pain, recurring running injuries, or want to improve your running mechanics, a movement assessment can be a valuable first step.