Femoral Neck Stress Fractures and Stress Reactions: What You Need to Know

Ever had hip or groin pain that creeps in during a run and eases once you stop? It could be more than just muscle tightness. Femoral neck stress fractures and stress reactions are uncommon, but they’re high-risk injuries that need early attention. The good news is that with the right approach, recovery is usually excellent.

What Is a Stress Fracture / Stress Reaction?

Bone is constantly breaking down and rebuilding itself in response to the loads we place on it. When training builds up faster than the bone can adapt, small areas of damage start to accumulate. Early on, this shows up as a stress reaction- swelling and irritation within the bone with no actual crack. If the loading continues, this can progress to a stress fracture- a visible crack in the bone. Femoral neck stress injuries are less common than stress fractures elsewhere in the body (like the shin or foot), but they’re taken seriously because of their location and the potential for complications if missed.

Risk Factors

• A rapid increase in training volume or intensity (a common trigger, especially in runners and military recruits)
• Low bone density
• Menstrual irregularities and/or inadequate nutrition relative to training demands (sometimes called RED-S, or the Female Athlete Triad)
• Being female
• Low body weight
• A previous stress fracture
• Training/biomechanical factors such as footwear or running technique
• Possible genetic factors affecting bone strength

Signs and Symptoms

• Gradual, non-traumatic onset of deep hip or groin pain
• Pain that worsens with running or weight-bearing activity
• Pain that eases with rest
• Occasionally felt more in the buttock or thigh than the groin
• Pain with certain hip movements, especially at end range
• Pain reproduced by hopping on the affected leg
• Symptoms that build over weeks alongside increasing training load

Diagnosis

Diagnosis starts with a thorough history (training load, menstrual history, nutrition) and a physical exam of the hip and surrounding areas. X-rays are often normal in the early stages, so MRI is the gold-standard test- it can pick up changes in the bone well before anything shows on an X-ray. Bloodwork (vitamin D, calcium) and sometimes a bone density scan may also be recommended. Because delayed diagnosis can lead to complications, it’s important to get persistent symptoms checked early rather than waiting it out.

Physiotherapy plays a key role in recovery, guided by one simple principle: reduce the load enough to let the bone heal, then gradually build it back up.

• Guiding an appropriate period of rest or reduced weight-bearing, based on the severity of the injury
• Keeping you fit through pain-free cross-training options like cycling or swimming
• Building strength through the hip and leg to support the bone as it heals
• A structured, step-by-step return to running program, progressed based on how the body responds rather than a fixed timeline
• Identifying and addressing the underlying cause e.g. training errors, nutrition, or bone health, to reduce the risk of it happening again
• Setting realistic expectations, since recovery can take anywhere from several weeks to a few months

The Takeaway

Femoral neck stress injuries are uncommon but important to catch early, especially in runners with gradually worsening hip or groin pain. Early diagnosis and a well-guided physiotherapy program give most people an excellent chance of a full return to activity.

If you have persistent hip or groin pain that builds with activity and eases with rest, get it assessed.