Author: admin

Stress Fracture Incidence

Stress Fracture Assessment & Treatment

Stress Fracture Incidence
Stress Fracture Incidence

Stress fractures of bone are a common injury seen in all types of sport and are a debilitating injury which can hurt a lot, preventing sports participation and maximum performance. The media often mentions stress fractures when sportspeople are unavailable for their event/sport but there is usually a vague sense of no clear return to play when these injuries are discussed. No moment of injury is usually seen either which tends to add the mystique and angst that typically accompanies a stress fracture diagnosis. This lack of injury moment or trauma adds to the distress of the athlete too when they are advised to not play for many weeks despite not feeling anything sinister has occurred.

Stress fractures can affect almost any bone in the body depending on the type of activity you perform. Lower limb stress injuries are the most common with tibia stress fractures and foot stress fractures being the most common in runners and other impact sports. It is not uncommon for gymnasts and dancers to develop stress injuries of the upper limb and ribs. Dancers, gymnasts and cricket bowlers also commonly develop stress injuries in the spine (pars stress fractures) due to the unique movements associated with their sports.

Stress Fracture Symptoms

Typically, stress fractures evolve slowly and are noticed as a gradual increase in localised pain, usually over a bony area such as the middle of the shin bone (tibia). The pain is usually brought on by weight-bearing or impact activity. The pain is in response to the bone’s inability to tolerate the force going through it. Hence the pain is worse when exercising and usually much improved when resting the affected area. However, 50% of stress injuries can cause night pain.

Typical examination findings are a localised area of tenderness on a bone. This may be associated with a small lump and swelling. The pain is often worse with recurrent hopping.

Although most bone stress injuries show themselves as a progressive increase in pain, the concern is a sudden failure of the bone. Bone failure is most likely to be seen if the pain is ignored and usually requires surgical intervention and a prolonged recovery period. Most recently, sudden bone failure was seen in the UFC bout between Conor McGregor and Dustin Poirier where a reported underlying stress fracture resulted in a complete tibial fracture.

What is a Stress Fracture?

Bone stress injuries are an accumulation of bone fatigue that results in a loss of structural and functional integrity. Every time we load our bone we cause microdamage to the collagen fibres and bone matrix. This stimulates bone cells known as osteoblasts, octeoclasts and osteocytes to respond to this microdamage. Typically after exercise our body mops up this ‘microdamage’ and strengthens the bone and remodels so the bone can tolerate MORE load in the future. This process takes a period of time to occur. Higher training intensity, particularly impact training, results in more microdamage than lower training intensity. If you participate in regular high intensity training without allowing adequate time for bone repair and remodelling, the microdamage never fully recovers and slowly accumulates.

Normal Bone Response To Load
Normal Bone Response To Load

As microdamage accumulates, the bone can develop signs of further injury known as microcracks. These are more definable issues in the structure of the bone. These microcracks aren’t visible like a traumatic fracture but are the early stages of a stress fracture. This phase is referred to as a bone stress injury. There are microfractures present but no visible crack on imaging. Bone is often symptomatic at this stage although it is possible to have signs of bone stress on MRI without pain.


Bone micro cracks
Electron microspopy view of bone micro cracks

Persistence of exercise allows microfractures to coalesce into macrofractures. Macrofractures are visible on imaging techniques as cracks in the bone. These cracks can progress through the entire width of the bone with time and result in sudden decompensation of the bone as seen in McGregor’s leg in the above image.

Why Do Stress Fractures Happen?

Th primary reason for a bone stress fracture to happen is training overload. As mentioned previously, the bone is exposed to recurrent bouts of exercise that cause more damage than the bone can recover from over a short period of time. So any changes in training volume, frequency or intensity increase the odds of developing a stress injury. The largest risk though is increasing the amount of impact loading in your training program.

However, development of stress injuries is usually multifactorial. These other factors need to be assessed and addressed in your recovery pathway.

Significant risk factors include:


This can influence the amount of force that your bone is exposed too. Changing training surface or footwear can result in sudden changes of bone loading exposure (known as ground reaction forces) and increase microdamage accumulation.


Bone health (mineral density, collagen organisation and quantity) is influenced by many factors.

Calcium Intake: Bone mineral is predominantly formed from calcium, therefore a lack of adequate calcium means bones do not have the necessary building blocks to build and maintain normal healthy bone. A common mistake is thinking a normal calcium blood test means calcium intake is adequate. In fact, the body protects blood calcium at all costs and will leach calcium out of the bones to maintain normal blood calcium. A normal blood calcium test doesn’t tell you much about your bone health in most cases.

Vitamin D Levels: Vitamin D plays a crucial role in how our body processes and absorbs calcium. 90% of our Vitamin D comes directly from sunlight. Low levels of Vitamin D increase the odds of poor bone health via its influence on calcium. Most blood tests suggest a Vitamin D level less than 50 nmol/L is low, but there is an increased incidence of bone stress injuries when levels are less than 75 nmol/L.

RELATIVE ENERGY DEFICIENCY SYNDROME (RED-S): Having persistently lower energy intake (dietary consumption of calories) than the amount of energy expended (calories burnt off) results in inefficiencies in many of the systems that maintain normal body function. Energy is required for normal bone remodelling and turnover. Low energy slows this process resulting in ‘stale’ bone that can be injured more easily. Low energy also affects sex hormone production (oestrogen and testosterone) and these hormones are anabolic to bone (promote growth and strength). If these hormones are not produced in adequate amounts, low bone mineral density and poor structure can result. This is a type of secondary osteopaenia / osteoporosis.

BIOMECHANICS & STRENGTH: Most areas of bone stress occur at specific points where load has been focussed. This focussing of load can be amplified by asymmetric biomechanics, abnormal movement patterns and muscle strength weakness. Interestingly though, there is no association of pes planus (flat feet) and the development of stress injuries.

GROWTH SPURTS: During growth spurts the bones grow faster than they can be mineralised. This results in a period of relative weakness (transient osteopaenia). Some studies suggest that growing by more than 0.6cm per month correlates to an increase in injury risk of 63%. This is why it is common to see teenagers with bone stress injuries.

FEMALE GENDER: Due to differences in bone width, muscle strength and hormonal influences as well as factors that are not understood, females have higher rates of stress injuries than males. In the military up to 17% of females develop bone stress injuries vs 6% of their male counterparts. These rates are higher in females with known alterations in their menstrual cycle. Normal menstrual cycle cannot be assessed in females using the oral contraceptive pill as the medication triggers menstruation regardless of the underlying physiology within the body. Taking the oral contraceptive pill does not compensate for having poor internal production of sex hormones.

OTHER: Several other factors influence vulnerability to bone stress injuries including your genetic risk (have your parents or siblings had any stress injuries?), parathyroid/thyroid hormone problems, smoking, excess alcohol consumption and other chronic illnesses.

Stress Fracture Diagnosis

Most stress fractures can be diagnosed clinically from the story you tell and the examination from the doctor. However, prognosis (how long it will take to recover) of the stress fracture and contribution of other factors to the injury may require further assessment including;

  • XR: Useful in chronic and higher grade injuries
  • MRI: Excellent at detecting early injuries and helps classify degree of stress injury present
  • Dietary assessment: sometimes a formal assessment with a SDA Sports Dietitian is needed to formally quantify your energy needs
  • Blood tests including assessment of bone physiology and hormone status
  • Bone mineral density testing via DEXA scan

Stress Fracture Grading

Stress injuries exist on a continuum. The further down the continuum towards a macrofracture, the longer the recovery time is likely to be. Several grading systems have been proposed but essentially the key components are:

  • Grade 1: Asymptomatic bone oedema (microfractures) without any fracture line
  • Grade 2: Symptomatic bone oedema (microfractures) without any fracture line
  • Grade 3: Bone oedema with an undisplaced macrofracture
  • Grade 4: A displaced macrofracture (see Conor McGregor’s leg)

In general, lower grade stress injuries tend to heal faster. Bone oedema cannot be seen on an X-ray, CT scan or MRI, so staging of early injuries needs an MRI or a bone scan. Bone scans are excellent diagnostic tools but expose patients to a moderate amount of radiation. Given MRI indentifies stress injuries just as well as a bone scan, an MRI is the investigation of choice as there is no radiation with an MRI.

Grade 2 Foot Bone Stress Injury
Grade 2 Foot Bone Stress Injury
Grade 3 Tibial Bone Stress Injury
Grade 3 Tibial Bone Stress Injury












Stress Fracture Treatment

The primary treatment is to stop exposing your stress injury to force that triggers pain. If you still have pain with walking, then your bone is struggling to cope with walking and you will need to stay off your feet or go on crutches.

A walking boot is often prescribed but this does not necessarily reduce the force going through your bones. However, it will probably slow you down so the total force your bone is exposed to throughout a day will be less. There are some foot stress injuries that will respond well to a boot if the boot has a forefoot rocker, this allows you to offload the forefoot.

It is essential that any stress fracture is assessed by a health professional and preferably by a doctor. Certain stress fractures need specific treatment as they are at high risk of not healing. These high risk stress fractures include:

  • 5th metatarsal
  • Navicular (foot)
  • Anterior tibial
  • Neck of femur
  • Pelvic
  • Sacrum
  • Spinal (pars)

Return to sports programs are highly variable and need to be individualised. Any return to sport program should be supervised by a health professional with experience in stress fracture management.

Stress Fracture Return To Sport Pathway
Possible Stress Fracture Return To Sport Pathway

Once you have been able to walk painfree for over a week, you may be able to slowly return to some weight-bearing activity. There is no exact science to progressing your exercise but the underlying principle is that any activity should cause NO pain. Most people can return to alternate day training at approximately 30-50% of their pre-injury training volume once they have been walkking painfree for over a week. This training volume can be slowly increased week by week until a full return to sport is achieved. Any pain experienced normally means a period of rest before restarting at a slightly lower painfree exercise volume again.

Maintaining aerobic fitness is possible during this period by substituting non-impact training for your impact training, this is known as cross-training. Good cross-training options include deep water running, swimming, eliptical trainer, cycling and sometime seated or lying resistance training.

Restoration of normal strength and correction where possible of abnormal biomechanics will form part of your complete treatment pathway. This is where a good relationship between your treating doctor and physiotherapist is essential.

Complete treatment of a stress fracture needs assessment by a doctor that specialises in musculoskeletal injuries such as a Sports & Exercise Medicine Physician. They will assess all of the previous risk factors mentioned and try and correct these. This is an often overlooked but essential part of treatment and the reason why many athletes have recurrent injuries.

There are some additional treatments that can aid recovery as well. There is some preliminary science suggesting supplementing with Vitamin D and calcium during the period of bone healing can help recovery even in the absence of any deficiencies.

Some stress fractures benefit from a pneumatic air brace such as tibial stress fractures. Fractures that have delayed healing may benefit from a bone stimulator treatment known as Low-Intensity Pulsed UltraSound (or LIPUS). There are also some medications that are being researched into their effect on speeding up bone stress injury healing including teriparatide and bisphosphonates.

How Do You Prevent Stress Fractures

As with all injuries, prevention is better than cure. The prevention of these injuries comes back to our previous risk factors. To minimise your chance of a new or recurrent stress injury, my recommendation would be:

  • Do not change your total impact-related training volume by more than 10% per week.
  • Periodise your training to allow your body time to adapt to your training loads. This can be supervised by a health professional or strength and conditioning coach.
  • When changing surfaces, footwear, technique or going through a period of growth; temporarily reduce your training volumes and slowly phase in new changes.
  • Maintain an energy intake that meets your energy requirements. Warning signs include a lack of performance improvement despite training, alterations in your menstrual cycle and weight loss.
  • Meet your Vitamin D and calcium requirements. This is especially important in the pubertal years when most bone mineral is deposited. 90% of bone mass is accrued before you turn 18 years old.

At Newcastle Sports Medicine we strive to be the best we can so we can help patients with the most up to date treatment available and keep you active and healthy.

If you would like to see any of our health professionals you can book appointments online here with our physios or call (02) 4910 0805 to make an appointment with our team of Sports Medicine Doctors and Sports Physios.


Chronic Groin Pain – More Than Just Osteitis Pubis

Written by Tim Schneider – APA Titled Sports Physiotherapist

Groin Pain Background

Chronic groin pain is an often debilitating condition and one for which the recovery is rarely smooth. One of the biggest challenges when dealing with groin pain is that, put simply, there is a lot of stuff going on there. All the muscles, tendons, joints and ligaments are very close anatomically and interact with each other meaning that it is often difficult to differentiate between structures. Clients commonly present with multiple structures involved (research would suggest this occurs in over 40% of cases) meaning getting a clear answer or diagnosis can sometimes be difficult.

Groin Pain Incidence

Groin pain is responsible for approximately 25% of AFL season injuries, 21% of Football/Soccer injuries and is more common in kicking sports and Ice Hockey. Approximately 1 in 3 professional athletes carry groin pain over the season break and will then start the next season with a pre-existing injury for the next medical team to manage. Commonly, the diagnosis may have been oversimplified considering only the adductor muscles as a cause in isolation resulting in an inadequate rehabilitation program and delayed recovery.

In the past, any pain in the groin that persisted for longer than 6 weeks was termed “Osteitis Pubis” which still gets used in media reports today. Unfortunately, there was no clear definition of what this involved which then impacted on our ability to better manage and research it. So, a few years ago, they put a group of 25 experts into a room in Doha and didn’t let them out until they had some consensus on defining groin pain, which became known as the Doha Agreement. The terminology was simplified indicating a general structure using the specific entities of adductor-, inguinal-, pubic- and iliopsoas- related groin pain as well as hip-related groin pain. All of the areas can refer pain into the groin, but may require differing rehabilitation pathways to recovery.

Before we get to the rehabilitation pathway, it is important to understand some of the anatomical structures involved.

Pubic Symphysis Anatomy

The pubic symphysis is a secondary cartilaginous joint, consisting of a wedge-shaped fibrocartilaginous interpubic disc situated between two layers of hyaline cartilage, which line the medial surfaces of the pubic bones. It is reinforced by 4 strong ligaments and surrounding muscles. The adductor longus, adductor brevis and rectus abdominus attach either side of the anterior pubic ligament and interpubic disc. The attachment of the adductor muscles via the interpubic disc to the rectus abdominus provides a mechanism for force transmission across the pubic symphysis.

Pubic symphysis Anatomy

The pubic symphysis is most susceptible to shearing forces, suggesting that force created by the adductor muscles and rectus abdominis can influence injury risk. The activation of the transversus abdominis provides compression across the superior portion of the pubic symphysis and works with the inferior pubic ligament and pelvic floor muscles to increase stability of the pubic symphysis. This requires effective muscle activation and strength of the above muscles and possibly weakness or poor muscle activation patterns can influence injury presentation and recovery.

Pubic symphysis forces

Tendons around the Groin Region

Adductor Kicking forces

Tendons may be affected by overloading through excessive exercise or strain beyond their capacity, but conversely may also become pathological through underloading. This process usually affects the underside of the tendon and is known as “Stress Shielding” where the tendon is not loaded enough in exercise which then leads to deconditioning resulting in tendon degeneration.

The most common of these tendons involved in groin pain are the Adductor Longus and the Rectus Abdominis. This commonly relates to increased anterior pelvic tilt or pelvic rotation causing increased length and subsequent load in these tendons. This is particularly the case in kicking sports as this picture shows, however is also significantly loaded in change of direction activities and sports using large range of hip motion such as dance and gymnastics.

Inguinal Canal Anatomy

The inguinal canal is a passage in the abdominal wall which conveys the spermatic cord in men and the round ligament in women as well as two small nerves from the abdominal cavity. The canal is larger and more prominent in men and the surrounding musculature is less developed than that in females. There may be a potential weakness in the abdominal wall which may be genetic or acquired and therefore a common site of herniation. The sides and roof of the canal are comprised of abdominal muscles and fascia. Of particular note are the transversus abdominis and internal oblique muscles which are commonly described as creating a “co-joined” or “conjoint” tendon where they insert onto the pubic tubercle. On contraction, they create a “window shutter” type mechanism to reduce the size of the external opening during athletic activity. If this mechanism fails, the external opening remains open and creates greater potential for bulging of the posterior abdominal wall, causing potential hernia.  

Inguinal canal anatomy
Inguinal Canal Anatomy

Another potential source of injury around this region is to the external oblique musculotendinous complex which is responsible for trunk rotation. These structures can commonly interact and coexist with adductor related pain and once again is commonly found in kicking sports or martial arts.

The Iliopsoas Muscle

Iliopsoas anatomy function

The Iliopsoas comprises of both the Iliacus and Psoas Major muscles which in most people combine to form a fused tendon before it inserts on the femur. The Psoas Major originates from the lower border of the T12 vertebra to the upper border of the L5 vertebra and has a role as a lumbar stabiliser as well as a hip flexor, while the Iliacus works over the hip joint and is responsible for early hip flexion in the running cycle. These muscles have a large role to play in tasks and sports that involve kicking and high speed running as they constantly are being stretched and are consequently working in a lengthened position. The Iliopsoas is open to overload particularly when the athlete cannot control the amount of pelvic movement when running or kicking which may lead to injury.

Other Groin Pain Diagnosis

Of course, there are other potential causes of groin pain in addition to those already described. Pain can be referred from the spine or SIJ, or from abdominal organs such as in appendicitis. Additionally, nerve entrapment or irritation can refer pain into the groin and mimic a more mechanical presentation and requires careful assessment to identify. The most common of these to consider are those that pass through the inguinal canal- the ilioinguinal and genitofemoral nerves, which can present with nearly identical pain patterns as adductor, pubic or inguinal related groin pain. There are also some serious problems that must be considered and ruled out including infection, tumours and autoimmune conditions. 

Causes of Groin Pain

The factors leading to groin pain are often multi-factorial usually related to load but also the athlete’s mechanics of movement. There have been only a small handful of specific risk factors identified including adductor strength, previous injury, age and level of sport participation. Given this lack of information, it has made researching and preventing injuries more difficult. It is important to recognise any change in training or kicking loads, or changed team role that may have contributed to the onset of symptoms.

An interesting study by Falvey in 2016 suggested that those athletes with groin pain of any entity or cause had altered movement patterns when cutting or changing direction and he suggested that retraining these patterns may provide improvement of groin related symptoms and reduced injury recurrence.

There does also appear to be a relationship between hip range of motion and the risk of groin pain. While the type of groin pain implicated is not specific to any entity, the principle of absorbing high sports-related forces in a smaller “anatomical workspace” does make sense. Research by Igor Tak (2017) showed that if both hips have reduced total range of motion there is increased risk of some form of groin injury.

Groin Pain Treatment

There has not been much quality research on physiotherapy and exercise paradigms for long standing groin pain, however there have been 5 main studies over the past 20 years all using a similar protocol designed by Per Holmich in 1999. This study looked at athletes who had ceased sport participation and the undertook a 2 stage exercise program after which 78% returned to sport.

Holmich used a combination of abdominal and groin strengthening with balance and single leg control exercises loading across the pubic symphysis to achieve this outcome. While looking at this protocol, I  do question the exercise selection with our more recent understanding of this region however 4 subsequent studies that have either used of modified this protocol continue to report well over 50% success within 4 months.

Holmich Protocol Module 1
Holmich protocol – Module 1

More recently, research by Enda King, an Irish Sports Physiotherapist, has focussed on a more mechanical approach to improve movement patterns following on the work by Falvey. While this has not utilised specific adductor strengthening, his approach has showed significant promise with return to sport rates being high in significantly less time that protocols involving the Holmich exercises.

Holmich Protocol Module 2
Holmich Protocol – Module 2

While this may be seen as a significant change to the management of this often complex region, I do believe we need to consider both approaches with any individual athlete. Individual variations in presentation and cause are exceedingly high requiring a structured assessment to classify the entity or entities most likely involved in each case, which then requires an individual specific approach to maximise effectiveness of the program. This is certainly not an area that we adopt a one-size-fits-all policy and will likely require both specific exercise targeted at objective findings as well as mechanical retraining to improve outcomes and prevent a return of symptoms when the athlete restarts sport.

Other Groin Pain Treatment Options

In cases where groin pain has proven to be recalcitrant or not improving to allow the athlete to successfully return to sport, involvement of Sports and Exercise Physicians, sports Physiotherapsits or other groin specialists may be required. This can assist with treatment direction and consider other causes for the symptoms to persist as well as provide adjunctive treatment options. Surgery is commonly seen as another option and adductor lengthening surgery (an adductor tenotomy) can restore function in some patients.

Groin Pain Summary

Consequently, any client with longstanding groin pain needs a comprehensive history and examination to identify factors relating to the onset of their condition which can then allow more specific direction to plan an effective treatment plan. We have to recognise that the groin is a complex area, requiring a structured and evidence based approach allowing  consistently high outcomes. While recovery usually takes place over 3-6 months, there are effective management strategies to get you back on the field in the interim.

If you have chronic groin pain that is limiting your sporting activity and want to get on the road to recovery, call one of our team at Newcastle Sports Medicine on 4910 0805.

Sports physio training

Physiotherapists are Not All Equal – Neither are the Treatments Frequently Used

Do you know how to assess if you are seeing the correct physiotherapist? We explain the significance of post-graduate physiotherapy qualifications. We also discuss treatments that are considered not beneficial for treatment of common injuries such as ankle sprains and low back pain.

Read more

Injured Your Anterior Cruciate Ligament (ACL)? How To Improve Your Chances of Returning To The Sport You Love

Anterior cruciate ligament injuries can be devastating. Fortunately a lot can be done to improve your knee both before & after surgery. Did you know that pre-operative rehab improves your chances of returning to sport after an ACL reconstruction? Read about what you can do to optimise your recovery from an ACL injury.

Read more